Home > Products > State Listing > Indiana Data
Latest:
 AFDIND |  AFDIWX |
  [top]

000
FXUS63 KIND 011814 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
111 PM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...

ISSUED AT 1253 PM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL GO BACK AND FORTH IN BETWEEN MVFR AND IFR
FOR THE REST OF THIS AFTERNOON...LOWER TO IFR ONCE MORE THIS
EVENING WITH A FINAL PUSH OF SNOW MOVING THROUGH THE AREA AND THEN
IMPROVE TO MVFR EARLY MONDAY MORNING. THEN FINALLY VFR BY EARLY
MONDAY AFTERNOON.

A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE ACROSS SOUTH CENTRAL
INDIANA THIS EVENING AND PULL AWAY FROM THE AREA BY LATE MONDAY
MORNING. LIFT WITH THIS SYSTEM HAS INCREASED ACROSS THE REGION WHICH
HAS ALLOWED MANY DIFFERENT TYPES OF PRECIPITATION TO DEVELOP AT
THE TERMINALS...RANGING FROM PLAIN SNOW AT KLAF TO MAINLY RAIN
SOUTH AT KBMG. AND THEN ONE OR THE OTHER...OR EVEN A MIXTURE AT
SITES KIND AND KHUF. THIS HAS OF COURSE RESULTED IN THE LOWERING
OF FLIGHT CONDITIONS...MOSTLY TO MVFR BUT ALSO IFR IN A FEW CASES
OF MODERATE TO HEAVY RAIN OR SNOW.

COLDER AIR WILL WORK INTO THE AREA BY THIS EVENING AND ALL
TERMINALS SHOULD SEE A TRANSITION TO ALL -SN BEFORE THE SYSTEM
EXITS THE REGION. FLIGHT CONDITIONS SHOULD ALSO LOWER TO IFR...IF
THEY HAVE NOT ALREADY THROUGH THIS EVENING AND THEN THE AREA
SHOULD SEE SOME IMPROVEMENT TO MVFR AND LATER VFR AS THE SYSTEM
QUICKLY ACCELERATES FROM THE AREA LATER MONDAY MORNING.

SOUTHEAST WINDS AROUND 8 KNOTS CURRENTLY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS
AFTER THE SURFACE LOW PRESSURE SYSTEM PASSES THROUGH.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 011814 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
111 PM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...

ISSUED AT 1253 PM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL GO BACK AND FORTH IN BETWEEN MVFR AND IFR
FOR THE REST OF THIS AFTERNOON...LOWER TO IFR ONCE MORE THIS
EVENING WITH A FINAL PUSH OF SNOW MOVING THROUGH THE AREA AND THEN
IMPROVE TO MVFR EARLY MONDAY MORNING. THEN FINALLY VFR BY EARLY
MONDAY AFTERNOON.

A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE ACROSS SOUTH CENTRAL
INDIANA THIS EVENING AND PULL AWAY FROM THE AREA BY LATE MONDAY
MORNING. LIFT WITH THIS SYSTEM HAS INCREASED ACROSS THE REGION WHICH
HAS ALLOWED MANY DIFFERENT TYPES OF PRECIPITATION TO DEVELOP AT
THE TERMINALS...RANGING FROM PLAIN SNOW AT KLAF TO MAINLY RAIN
SOUTH AT KBMG. AND THEN ONE OR THE OTHER...OR EVEN A MIXTURE AT
SITES KIND AND KHUF. THIS HAS OF COURSE RESULTED IN THE LOWERING
OF FLIGHT CONDITIONS...MOSTLY TO MVFR BUT ALSO IFR IN A FEW CASES
OF MODERATE TO HEAVY RAIN OR SNOW.

COLDER AIR WILL WORK INTO THE AREA BY THIS EVENING AND ALL
TERMINALS SHOULD SEE A TRANSITION TO ALL -SN BEFORE THE SYSTEM
EXITS THE REGION. FLIGHT CONDITIONS SHOULD ALSO LOWER TO IFR...IF
THEY HAVE NOT ALREADY THROUGH THIS EVENING AND THEN THE AREA
SHOULD SEE SOME IMPROVEMENT TO MVFR AND LATER VFR AS THE SYSTEM
QUICKLY ACCELERATES FROM THE AREA LATER MONDAY MORNING.

SOUTHEAST WINDS AROUND 8 KNOTS CURRENTLY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS
AFTER THE SURFACE LOW PRESSURE SYSTEM PASSES THROUGH.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 011810
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
110 PM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...

ISSUED AT 1253 PM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL GO BACK AND FORTH IN BETWEEN MVFR AND IFR
FOR THE REST OF THIS AFTERNOON...LOWER TO IFR ONCE MORE THIS
EVENING WITH A FINAL PUSH OF SNOW MOVING THROUGH THE AREA AND THEN
IMPROVE TO MVFR EARLY MONDAY MORNING. THEN FINALLY VFR BY EARLY
MONDAY AFTERNOON.

A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE ACROSS SOUTH CENTRAL
INDIANA THIS EVENING AND PULL AWAY FROM THE AREA BY LATE MONDAY
MORNING. LIFT WITH THIS SYSTEM HAS INCREASED ACROSS THE REGION WHICH
HAS ALLOWED MANY DIFFERENT TYPES OF PRECIPITATION TO DEVELOP AT
THE TERMINALS...RANGING FROM PLAIN SNOW AT KLAF TO MAINLY RAIN
SOUTH AT KBMG...AND A ONE OF THE OTHER OR EVEN A MIXTURE AT SITES
KIND AND KHUF. THIS HAS OF COURSE RESULTED IN THE LOWERING OF FLIGHT
CONDITIONS...MOSTLY TO MVFR BUT ALSO IFR IN A FEW CASES OF
MODERATE TO HEAVY RAIN OR SNOW.

COLDER AIR WILL WORK INTO THE AREA BY THIS EVENING AND ALL
TERMINALS SHOULD SEE A TRANSITION TO ALL -SN BEFORE THE SYSTEM
EXITS THE REGION. FLIGHT CONDITIONS SHOULD ALSO LOWER TO IFR...IF
THEY HAVE NOT ALREADY THROUGH THIS EVENING AND THEN THE AREA
SHOULD SEE SOME IMPROVEMENT TO MVFR AND LATER VFR AS THE SYSTEM
QUICKLY ACCELERATES FROM THE AREA.

SOUTHEAST WINDS AROUND 8 KNOTS CURRENTLY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS
AFTER THE SURFACE LOW PRESSURE SYSTEM PASSES THROUGH.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 011810
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
110 PM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011800Z TAF ISSUANCE/...

ISSUED AT 1253 PM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL GO BACK AND FORTH IN BETWEEN MVFR AND IFR
FOR THE REST OF THIS AFTERNOON...LOWER TO IFR ONCE MORE THIS
EVENING WITH A FINAL PUSH OF SNOW MOVING THROUGH THE AREA AND THEN
IMPROVE TO MVFR EARLY MONDAY MORNING. THEN FINALLY VFR BY EARLY
MONDAY AFTERNOON.

A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE ACROSS SOUTH CENTRAL
INDIANA THIS EVENING AND PULL AWAY FROM THE AREA BY LATE MONDAY
MORNING. LIFT WITH THIS SYSTEM HAS INCREASED ACROSS THE REGION WHICH
HAS ALLOWED MANY DIFFERENT TYPES OF PRECIPITATION TO DEVELOP AT
THE TERMINALS...RANGING FROM PLAIN SNOW AT KLAF TO MAINLY RAIN
SOUTH AT KBMG...AND A ONE OF THE OTHER OR EVEN A MIXTURE AT SITES
KIND AND KHUF. THIS HAS OF COURSE RESULTED IN THE LOWERING OF FLIGHT
CONDITIONS...MOSTLY TO MVFR BUT ALSO IFR IN A FEW CASES OF
MODERATE TO HEAVY RAIN OR SNOW.

COLDER AIR WILL WORK INTO THE AREA BY THIS EVENING AND ALL
TERMINALS SHOULD SEE A TRANSITION TO ALL -SN BEFORE THE SYSTEM
EXITS THE REGION. FLIGHT CONDITIONS SHOULD ALSO LOWER TO IFR...IF
THEY HAVE NOT ALREADY THROUGH THIS EVENING AND THEN THE AREA
SHOULD SEE SOME IMPROVEMENT TO MVFR AND LATER VFR AS THE SYSTEM
QUICKLY ACCELERATES FROM THE AREA.

SOUTHEAST WINDS AROUND 8 KNOTS CURRENTLY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS WITH GUSTS TO 20 TO 25 KNOTS
AFTER THE SURFACE LOW PRESSURE SYSTEM PASSES THROUGH.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






  [top]

000
FXUS63 KIWX 011752
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1252 PM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 1238 PM EST SUN JAN 31 2015

LOW PRESSURE WILL MOVE NORTHEAST THROUGH SOUTHERN INDIANA TODAY
AND INTENSIFY. THE LOW WILL PUSH INTO CENTRAL PENNSYLVANIA BY
MONDAY MORNING. AS THIS MAJOR WINTER STORM CONTINUES TO TAKE
SHAPE...EXPECT MODERATE TO HEAVY SNOW TO CONTINUE INTO THE
EVENING. THEN INCREASING WINDS WILL CREATE BLOWING AND DRIFTING
SNOW FOR MUCH OF THE REGION THROUGH TONIGHT. TRAVEL WILL BECOME
DIFFICULT TO IMPOSSIBLE ACROSS MOST OF THE REGION THROUGH TONIGHT.
SNOW WILL DIMINISH THEN END FROM WEST TO EAST BY LATE TONIGHT AS
THE SYSTEM PULLS OFF TO THE EAST. SOME LINGERING LIGHT LAKE
EFFECT SNOW SHOWERS ARE POSSIBLE ACROSS SOUTHWEST LOWER MICHIGAN
AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY BRING
ADDITIONAL...BUT LESSER SNOW ACCUMULATIONS TO PORTIONS OF THE
SOUTHERN GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW
COMPLETE OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE
OHIO VALLEY AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG
WITH BLOWING AND DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK.
A PLUME OF MID AND UPPER LEVEL MOISTURE SPREADING INTO THE AREA
AHEAD OF THIS SYSTEM WILL HELP ENHANCE SNOWFALL AMOUNTS. THE
RIBBON OF -2C TO -5C AT 850 MB FAVORABLE FOR HEAVIER SNOW WILL
CONTINUE OVER MOST OF THE AREA FOR THE DURATION OF THE EVENT. THE
OVERALL TREND OF THE GFS IS FAVORED WITH A GRADUAL NORTH SHIFT OF
THE SFC LOW TRACK. FORECAST THERMAL PROFILES ALONG THE EXTREME
SOUTH PART OF THE FORECAST AREA VERY CLOSE TO A RAIN/SNOW MIX.
GIVEN THE NORTHERN MODEL SHIFT AND THE POTENTIAL FOR A RAIN/SNOW
MIX OVER THE FAR SOUTH...RAISED SNOWFALL AMOUNTS OVER FAR
SOUTHWEST LOWER MICHIGAN AND LOWERED AMOUNTS SLIGHTLY FROM MARION
TO PORTLAND. STILL EXPECT HEAVY SNOW WITH BLOWING SNOW THIS
AFTERNOON. THE COLD AIR WAS ALREADY SPREADING SOUTHWEST OUT OF
LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING RAPIDLY. THE
TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY
LATE AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT
SNOWFALL TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY
30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE
SUBSIDENCE ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY
ADDITIONAL ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN
CHANCE OF LIGHT SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN
RECENT TREND TO SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING
WINTER STORM SUNDAY NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED
ON TUESDAY OUTSIDE OF LAKE EFFECT CLOUDINESS WHICH WILL BE
ADVANCING EASTWARD WITH THE BACKING WIND PROFILES. NEW SNOW COVER
AND LOW LEVEL THERMAL TROUGHING ACROSS THE AREA WILL KEEP MAX
TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM
TRACKING INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH
ONLY A BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE
WILL KEEP LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE
PRONOUNCED WAVE IN NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY
LATE TUESDAY/WEDNESDAY WITH A BROAD ZONE OF ISENTROPIC UPGLIDE
ASSOCIATED WITH RETREATING COLD AIR DOME. GIVEN FAIRLY GOOD
AGREEMENT WITH OPERATIONAL EC/GFS AND BROAD NATURE OF FORCING
HAVE INCREASED TO POPS TO LIKELY FOR TUESDAY NIGHT WITH EARLY
INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH TYPE ACCUMULATION
POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA REGIME IN ADVANCE
OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF PRIMARY UPPER WAVE
USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS THE AREA...WHICH
MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER WEDNESDAY.
NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE FORECAST
WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1248 PM EST SUN FEB 1 2015

HEAVIEST SNOWFALL RATES COMBINED WITH BR/FZFG TO SUPPORT PRIMARILY
LIFR CONDS AT LEAST THROUGH LATE AFTERNOON/EARLY EVENING.
GRADUALLY VERTICAL MOTION AND THERMAL PROFILES WILL LEND TO
LESSENED RATES WITH IMPROVED CONDITIONS...WITH TRANSITION TO BLSN
AS PRIMARY VSBY REDUCING ELEMENT. FINALLY CONDS ABOVE
FUELING/ALTERNATE CRITERIA BY DAYBREAK AS SFC LOW BEGINS TO
ACCELERATE EWD...WITH SFC LOW INTO CNTL PA BY 12 UTC.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 011752
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1252 PM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 1238 PM EST SUN JAN 31 2015

LOW PRESSURE WILL MOVE NORTHEAST THROUGH SOUTHERN INDIANA TODAY
AND INTENSIFY. THE LOW WILL PUSH INTO CENTRAL PENNSYLVANIA BY
MONDAY MORNING. AS THIS MAJOR WINTER STORM CONTINUES TO TAKE
SHAPE...EXPECT MODERATE TO HEAVY SNOW TO CONTINUE INTO THE
EVENING. THEN INCREASING WINDS WILL CREATE BLOWING AND DRIFTING
SNOW FOR MUCH OF THE REGION THROUGH TONIGHT. TRAVEL WILL BECOME
DIFFICULT TO IMPOSSIBLE ACROSS MOST OF THE REGION THROUGH TONIGHT.
SNOW WILL DIMINISH THEN END FROM WEST TO EAST BY LATE TONIGHT AS
THE SYSTEM PULLS OFF TO THE EAST. SOME LINGERING LIGHT LAKE
EFFECT SNOW SHOWERS ARE POSSIBLE ACROSS SOUTHWEST LOWER MICHIGAN
AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY BRING
ADDITIONAL...BUT LESSER SNOW ACCUMULATIONS TO PORTIONS OF THE
SOUTHERN GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW
COMPLETE OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE
OHIO VALLEY AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG
WITH BLOWING AND DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK.
A PLUME OF MID AND UPPER LEVEL MOISTURE SPREADING INTO THE AREA
AHEAD OF THIS SYSTEM WILL HELP ENHANCE SNOWFALL AMOUNTS. THE
RIBBON OF -2C TO -5C AT 850 MB FAVORABLE FOR HEAVIER SNOW WILL
CONTINUE OVER MOST OF THE AREA FOR THE DURATION OF THE EVENT. THE
OVERALL TREND OF THE GFS IS FAVORED WITH A GRADUAL NORTH SHIFT OF
THE SFC LOW TRACK. FORECAST THERMAL PROFILES ALONG THE EXTREME
SOUTH PART OF THE FORECAST AREA VERY CLOSE TO A RAIN/SNOW MIX.
GIVEN THE NORTHERN MODEL SHIFT AND THE POTENTIAL FOR A RAIN/SNOW
MIX OVER THE FAR SOUTH...RAISED SNOWFALL AMOUNTS OVER FAR
SOUTHWEST LOWER MICHIGAN AND LOWERED AMOUNTS SLIGHTLY FROM MARION
TO PORTLAND. STILL EXPECT HEAVY SNOW WITH BLOWING SNOW THIS
AFTERNOON. THE COLD AIR WAS ALREADY SPREADING SOUTHWEST OUT OF
LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING RAPIDLY. THE
TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY
LATE AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT
SNOWFALL TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY
30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE
SUBSIDENCE ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY
ADDITIONAL ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN
CHANCE OF LIGHT SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN
RECENT TREND TO SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING
WINTER STORM SUNDAY NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED
ON TUESDAY OUTSIDE OF LAKE EFFECT CLOUDINESS WHICH WILL BE
ADVANCING EASTWARD WITH THE BACKING WIND PROFILES. NEW SNOW COVER
AND LOW LEVEL THERMAL TROUGHING ACROSS THE AREA WILL KEEP MAX
TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM
TRACKING INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH
ONLY A BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE
WILL KEEP LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE
PRONOUNCED WAVE IN NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY
LATE TUESDAY/WEDNESDAY WITH A BROAD ZONE OF ISENTROPIC UPGLIDE
ASSOCIATED WITH RETREATING COLD AIR DOME. GIVEN FAIRLY GOOD
AGREEMENT WITH OPERATIONAL EC/GFS AND BROAD NATURE OF FORCING
HAVE INCREASED TO POPS TO LIKELY FOR TUESDAY NIGHT WITH EARLY
INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH TYPE ACCUMULATION
POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA REGIME IN ADVANCE
OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF PRIMARY UPPER WAVE
USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS THE AREA...WHICH
MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER WEDNESDAY.
NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE FORECAST
WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1248 PM EST SUN FEB 1 2015

HEAVIEST SNOWFALL RATES COMBINED WITH BR/FZFG TO SUPPORT PRIMARILY
LIFR CONDS AT LEAST THROUGH LATE AFTERNOON/EARLY EVENING.
GRADUALLY VERTICAL MOTION AND THERMAL PROFILES WILL LEND TO
LESSENED RATES WITH IMPROVED CONDITIONS...WITH TRANSITION TO BLSN
AS PRIMARY VSBY REDUCING ELEMENT. FINALLY CONDS ABOVE
FUELING/ALTERNATE CRITERIA BY DAYBREAK AS SFC LOW BEGINS TO
ACCELERATE EWD...WITH SFC LOW INTO CNTL PA BY 12 UTC.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 011559
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1058 AM EST SUN FEB 1 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /REST OF TODAY AND TONIGHT/...

ISSUED AT 1058 AM EST SUN FEB 1 2015

WITH THE MORNING UPDATE HAVE ADDED SOME SNOW OR RAIN/SNOW BACK IN
SOUTH OF I70 FOR A FEW HOURS AS EVAPORATIVE COOLING HAS ALLOWED SOME
ACCUMULATING SNOW TO DEVELOP BUT THIS SHOULD BE BRIEF. THERE IS
STILL SIGNIFICANT WARM ADVECTION ALOFT AND EXPECT A CHANGEOVER TO
ALL RAIN FOR THESE AREAS MENTIONED BY EARLY THIS AFTERNOON. IN THE
EAST COULD SEE THE MIX EXTEND EVEN FURTHER NORTH. ACROSS THE
NORTHERN COUNTIES /WARNING AREA/ STILL LOOKING AT ALL SNOW...HEAVY
AT TIMES...AND DID NOT CHANGE AMOUNTS THERE. THE ADVISORY AREA COULD
SEE SOME MIX BUT THAT WAS ALREADY REFLECTED IN THOSE AMOUNTS. HIGH
TEMPERATURES STILL ON TRACK FOR LOW TO MID 30S NORTH AND LOW 40S
SOUTH.

PREVIOUS DISCUSSION FOLLOWS...

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 011443
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
943 AM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 011443
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
943 AM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 011443
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
943 AM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 011443
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
943 AM EST SUN FEB 1 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.

&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.

&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...

ISSUED AT 937 AM EST SUN FEB 1 2015

1430Z UPDATE...FEW CHANGES TO INTRODUCE PRECIP A FEW HOURS EARLIER
THAN ORIGINAL FORECAST. -SN BEING REPORTED AT HUF AND IND...AND
WILL BE SHORTLY AT LAF. WHILE -RA WILL CONTINUE AT BMG. A -RASN
MIX IS EXPECTED TO DEVELOP AND BECOME THE PREDOMINANT WX AT IND
WITH THE NEXT HOUR OR TWO...WITH IFR CONDITIONS TO FOLLOW.
OTHERWISE NO OTHER CHANGES WERE MADE AT THIS THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...SMF/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIWX 011153
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
653 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A MAJOR WINTER STORM WILL CONTINUE TO TAKE SHAPE TODAY...BRINGING
HEAVY SNOW ALONG WITH BLOWING AND DRIFTING SNOW TO MUCH OF THE
REGION THROUGH TONIGHT. TRAVEL WILL BECOME DIFFICULT TO IMPOSSIBLE
ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. SNOW WILL
DIMINISH LATE TONIGHT AS THE SYSTEM PULLS OFF TO THE EAST WITH
SOME LINGERING LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY
BRING ADDITIONAL SNOW ACCUMULATIONS TO PORTIONS OF THE SOUTHERN
GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 642 AM EST SUN FEB 1 2015

SNOW TO INCREASE IN INTENSITY...ESPECIALLY FROM MID MORNING TO
EARLY AFTERNOON AS ISENTROPIC LIFT CONTINUES TO STRENGTHEN AND AS
PRIMARY UPPER LEVEL TROUGH APPROACHES THE MID MS RIVER VALLEY.
LIFR CONDITIONS ARE EXPECTED THROUGH OF THE LATE MORNING THROUGH
EARLY EVENING PERIOD DUE TO THE COMBINATION OF HEAVY SNOW AND
INCREASING NORTHEAST WINDS (GUSTING TO AROUND 25 KNOTS) RESULTING
IN BLOWING SNOW/REDUCED VISIBILITIES. DEFORMATION FORCING TO ALLOW
SNOW TO CONTINUE INTO TONIGHT...BEFORE DIMINISHING DURING THE
OVERNIGHT HOURS. CONDITIONS TO IMPROVE TOWARD THE END OF THE
FORECAST VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 011153
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
653 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A MAJOR WINTER STORM WILL CONTINUE TO TAKE SHAPE TODAY...BRINGING
HEAVY SNOW ALONG WITH BLOWING AND DRIFTING SNOW TO MUCH OF THE
REGION THROUGH TONIGHT. TRAVEL WILL BECOME DIFFICULT TO IMPOSSIBLE
ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. SNOW WILL
DIMINISH LATE TONIGHT AS THE SYSTEM PULLS OFF TO THE EAST WITH
SOME LINGERING LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY
BRING ADDITIONAL SNOW ACCUMULATIONS TO PORTIONS OF THE SOUTHERN
GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 642 AM EST SUN FEB 1 2015

SNOW TO INCREASE IN INTENSITY...ESPECIALLY FROM MID MORNING TO
EARLY AFTERNOON AS ISENTROPIC LIFT CONTINUES TO STRENGTHEN AND AS
PRIMARY UPPER LEVEL TROUGH APPROACHES THE MID MS RIVER VALLEY.
LIFR CONDITIONS ARE EXPECTED THROUGH OF THE LATE MORNING THROUGH
EARLY EVENING PERIOD DUE TO THE COMBINATION OF HEAVY SNOW AND
INCREASING NORTHEAST WINDS (GUSTING TO AROUND 25 KNOTS) RESULTING
IN BLOWING SNOW/REDUCED VISIBILITIES. DEFORMATION FORCING TO ALLOW
SNOW TO CONTINUE INTO TONIGHT...BEFORE DIMINISHING DURING THE
OVERNIGHT HOURS. CONDITIONS TO IMPROVE TOWARD THE END OF THE
FORECAST VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 011153
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
653 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A MAJOR WINTER STORM WILL CONTINUE TO TAKE SHAPE TODAY...BRINGING
HEAVY SNOW ALONG WITH BLOWING AND DRIFTING SNOW TO MUCH OF THE
REGION THROUGH TONIGHT. TRAVEL WILL BECOME DIFFICULT TO IMPOSSIBLE
ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. SNOW WILL
DIMINISH LATE TONIGHT AS THE SYSTEM PULLS OFF TO THE EAST WITH
SOME LINGERING LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY
BRING ADDITIONAL SNOW ACCUMULATIONS TO PORTIONS OF THE SOUTHERN
GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 642 AM EST SUN FEB 1 2015

SNOW TO INCREASE IN INTENSITY...ESPECIALLY FROM MID MORNING TO
EARLY AFTERNOON AS ISENTROPIC LIFT CONTINUES TO STRENGTHEN AND AS
PRIMARY UPPER LEVEL TROUGH APPROACHES THE MID MS RIVER VALLEY.
LIFR CONDITIONS ARE EXPECTED THROUGH OF THE LATE MORNING THROUGH
EARLY EVENING PERIOD DUE TO THE COMBINATION OF HEAVY SNOW AND
INCREASING NORTHEAST WINDS (GUSTING TO AROUND 25 KNOTS) RESULTING
IN BLOWING SNOW/REDUCED VISIBILITIES. DEFORMATION FORCING TO ALLOW
SNOW TO CONTINUE INTO TONIGHT...BEFORE DIMINISHING DURING THE
OVERNIGHT HOURS. CONDITIONS TO IMPROVE TOWARD THE END OF THE
FORECAST VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 011153
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
653 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A MAJOR WINTER STORM WILL CONTINUE TO TAKE SHAPE TODAY...BRINGING
HEAVY SNOW ALONG WITH BLOWING AND DRIFTING SNOW TO MUCH OF THE
REGION THROUGH TONIGHT. TRAVEL WILL BECOME DIFFICULT TO IMPOSSIBLE
ACROSS THE REGION THIS AFTERNOON INTO THIS EVENING. SNOW WILL
DIMINISH LATE TONIGHT AS THE SYSTEM PULLS OFF TO THE EAST WITH
SOME LINGERING LAKE EFFECT SNOW SHOWERS POSSIBLE ACROSS SOUTHWEST
LOWER MICHIGAN AND NORTHWEST INDIANA ON MONDAY. ANOTHER SYSTEM MAY
BRING ADDITIONAL SNOW ACCUMULATIONS TO PORTIONS OF THE SOUTHERN
GREAT LAKES REGION TUESDAY NIGHT INTO EARLY WEDNESDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 642 AM EST SUN FEB 1 2015

SNOW TO INCREASE IN INTENSITY...ESPECIALLY FROM MID MORNING TO
EARLY AFTERNOON AS ISENTROPIC LIFT CONTINUES TO STRENGTHEN AND AS
PRIMARY UPPER LEVEL TROUGH APPROACHES THE MID MS RIVER VALLEY.
LIFR CONDITIONS ARE EXPECTED THROUGH OF THE LATE MORNING THROUGH
EARLY EVENING PERIOD DUE TO THE COMBINATION OF HEAVY SNOW AND
INCREASING NORTHEAST WINDS (GUSTING TO AROUND 25 KNOTS) RESULTING
IN BLOWING SNOW/REDUCED VISIBILITIES. DEFORMATION FORCING TO ALLOW
SNOW TO CONTINUE INTO TONIGHT...BEFORE DIMINISHING DURING THE
OVERNIGHT HOURS. CONDITIONS TO IMPROVE TOWARD THE END OF THE
FORECAST VALID PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 011101
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
600 AM EST SUN FEB 1 2015

.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.


&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.


&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.


&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...
ISSUED AT 600 AM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 011101
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
600 AM EST SUN FEB 1 2015

.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.


&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT
AREA...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.


&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.


&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 011200Z TAF ISSUANCE/...
ISSUED AT 600 AM EST SUN FEB 1 2015

FLIGHT CONDITIONS WILL WORSEN TO IFR OR LOWER BY MIDDAY AND THEN
IMPROVE TO MVFR AFTER MIDNIGHT MONDAY.

A STRENGTHENING LOW PRESSURE SYSTEM NEAR KANSAS MISSOURI BORDER WILL
MOVE TO SOUTH CENTRAL INDIANA BY 00Z MONDAY AND TO WESTERN
PENNSYLVANIA BY END OF THE FORECAST PERIOD.  MODELS INDICATE LIFT
WILL INCREASE ACROSS OUR REGION BY MIDDAY WHICH WILL ALLOW MIXED
RAIN AND SNOW TO INCREASE ACROSS OUR REGION.  THIS WILL RESULT WITH
LOWERING FLIGHT CONDITIONS.  LOW LEVEL THICKNESS INDICATE MOSTLY
SNOW AT KLAF AND MIXED RAIN AND SNOW ELSEWHERE...EXCEPT MOSTLY RAIN
AND KBMG. WITH MORE SNOW AT KLAF...FLIGHT CONDITIONS MAY BECOME LIFR
LATER TODAY.

SOUTHEAST WINDS UP TO 8 KNOTS TODAY WILL BECOME NORTHWEST THIS
EVENING AND INCREASE UP TO 15 KNOTS AND GUSTS TO 20 TO 25 KNOTS
AFTER SURFACE LOW PRESSURE SYSTEM PASSES BY.  COLDER AIR WILL SPREAD
INTO OUR REGION TONIGHT AND PRECIPITATION WILL BECOME ALL SNOW BY
MID OR LATE EVENING.

EXPECT FLIGHT CATEGORIES TO IMPROVE TO MVFR LATE TONIGHT AS LOW
PRESSURE CONTINUES ON TO THE EAST.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS











000
FXUS63 KIWX 011025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
525 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 011025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
525 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 524 AM EST SUN FEB 1 2015

MERGER OF NORTHERN STREAM AND SOUTHERN STREAM SYSTEMS NOW COMPLETE
OVER THE CENTRAL CONUS...WITH THIS STORM HEADED FOR THE OHIO VALLEY
AND WESTERN GREAT LAKES REGIONS. HEAVY SNOW ALONG WITH BLOWING AND
DRIFTING SNOW EXPECTED AS ADVERTISED LAST WEEK. A PLUME OF MID AND
UPPER LEVEL MOISTURE SPREADING INTO THE AREA AHEAD OF THIS SYSTEM
WILL HELP ENHANCE SNOWFALL AMOUNTS. THE RIBBON OF -2C TO -5C AT 850
MB FAVORABLE FOR HEAVIER SNOW WILL CONTINUE OVER MOST OF THE AREA
FOR THE DURATION OF THE EVENT. THE OVERALL TREND OF THE GFS IS
FAVORED WITH A GRADUAL NORTH SHIFT OF THE SFC LOW TRACK. FORECAST
THERMAL PROFILES ALONG THE EXTREME SOUTH PART OF THE FORECAST AREA
VERY CLOSE TO A RAIN/SNOW MIX. GIVEN THE NORTHERN MODEL SHIFT AND
THE POTENTIAL FOR A RAIN/SNOW MIX OVER THE FAR SOUTH...RAISED
SNOWFALL AMOUNTS OVER FAR SOUTHWEST LOWER MICHIGAN AND LOWERED
AMOUNTS SLIGHTLY FROM MARION TO PORTLAND. STILL EXPECT HEAVY SNOW
WITH BLOWING SNOW THIS AFTERNOON. THE COLD AIR WAS ALREADY SPREADING
SOUTHWEST OUT OF LOWER MICHIGAN WHERE TEMPERATURES WERE FALLING
RAPIDLY. THE TEMPERATURES DROP WAS MORE ACUTE THAN ADVOCATED BY THE
GFS...WHICH LENDS CREDENCE TO STRONGER WINDS THIS AFTERNOON INTO
EARLY TONIGHT. EXPECT SUBSTANTIAL BLOWING AND DRIFTING SNOW BY LATE
AFTERNOON...CAUSING SOME ROADS TO BECOME IMPASSIBLE. KEPT SNOWFALL
TOTALS IN THE DOUBLE DIGITS ALONG AND NORTH OF HIGHWAY 30.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 524 AM EST SUN FEB 1 2015

LONG TERM PERIOD TO BEGIN WITH CONCERN FOR LAKE EFFECT SNOW
SHOWERS...PRIMARILY ACROSS NORTHWEST INDIANA PORTIONS OF THE
FORECAST AREA WITH A PRIMARILY NORTHERLY FETCH. LIMITED/LOWERING
INVERSION HEIGHTS AND INCREASING MID LEVEL SYNOPTIC SCALE SUBSIDENCE
ALONG WITH BACKING LOW LEVEL WINDS SHOULD LIMIT ANY ADDITIONAL
ACCUMULATIONS TO LESS THAN AN INCH. DID MAINTAIN CHANCE OF LIGHT
SNOW ACROSS THE FAR EAST MONDAY MORNING GIVEN RECENT TREND TO
SLOWER/MORE AMPLIFIED SOLUTION REGARDING EXITING WINTER STORM SUNDAY
NIGHT. OTHERWISE...DECREASING CLOUDS EXPECTED ON TUESDAY OUTSIDE OF
LAKE EFFECT CLOUDINESS WHICH WILL BE ADVANCING EASTWARD WITH THE
BACKING WIND PROFILES. NEW SNOW COVER AND LOW LEVEL THERMAL
TROUGHING ACROSS THE AREA WILL KEEP MAX TEMPS IN THE TEENS.

AN ACTIVE NORTHWEST FLOW PATTERN IS IN STORE FOR MUCH OF THE
REMAINDER OF THE UPCOMING WEEK WITH A WEAK CLIPPER SYSTEM TRACKING
INTO THE AREA LATE MONDAY NIGHT/EARLY TUESDAY...BUT WITH ONLY A
BRIEF WINDOW OF DEEPER MOISTURE ASSOCIATED WITH THIS WAVE WILL KEEP
LOW CHANCE ACROSS MAINLY THE NORTHWEST. A MORE PRONOUNCED WAVE IN
NORTHWEST FLOW WILL REACH THE UPPER MS VALLEY LATE TUESDAY/WEDNESDAY
WITH A BROAD ZONE OF ISENTROPIC UPGLIDE ASSOCIATED WITH RETREATING
COLD AIR DOME. GIVEN FAIRLY GOOD AGREEMENT WITH OPERATIONAL EC/GFS
AND BROAD NATURE OF FORCING HAVE INCREASED TO POPS TO LIKELY FOR
TUESDAY NIGHT WITH EARLY INDICATIONS SUGGESTING A 1-3 OR 2-4 INCH
TYPE ACCUMULATION POSSIBLE. ANY MODERATION IN TEMPERATURES IN WAA
REGIME IN ADVANCE OF THIS WAVE WILL BE SHORT LIVED AS PASSAGE OF
PRIMARY UPPER WAVE USHERS IN ANOTHER ARCTIC FRONTAL BOUNDARY ACROSS
THE AREA...WHICH MAY ALSO SERVE AS A FOCUS FOR MORE LIGHT SNOW LATER
WEDNESDAY. NOT SIGNIFICANT CHANGES MADE TO THE REMAINDER OF THE
FORECAST WITH MODERATION IN TEMPERATURES EXPECTED AGAIN FOR
FRIDAY/SATURDAY.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...SKIPPER
LONG TERM...MARSILI
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 010952
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
452 AM EST SUN FEB 1 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 427 AM EST SUN FEB 1 2015

A STRONG STORM SYSTEM WILL IMPACT NORTHERN PORTIONS OF CENTRAL
INDIANA TODAY THROUGH EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES
AWAY FROM THE AREA ON MONDAY...FRIGID TEMPERATURES WILL RETURN TO
CENTRAL INDIANA. AFTER A BRIEF WARM-UP AROUND MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN AGAIN AT THE END OF THE WORK WEEK IN THE
WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD FRONT
WILL ALSO BE RESPONSIBLE FOR SNOW FROM TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT...MINOR ACCUMULATIONS EXPECTED.


&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

THE MAIN FOCUS CONTINUES TO BE THE WINTER STORM CURRENTLY
IMPACTING CENTRAL INDIANA.

CURRENT RADAR MOSAIC IS SHOWING A VAST AREA OF DRY CONDITIONS OVER
CENTRAL AND SOUTHERN INDIANA...WITH PRECIPITATION CONFINED TO THE
NORTHERN TIER OF COUNTIES. THIS COMBINED WITH WARMER TEMPS EARLIER
HAVE RESULTED IN LITTLE SNOW ACCUMULATION ACROSS MOST OF CENTRAL
INDIANA. LATEST IR SATELLITE SHOWS A LARGE PLUME OF MOISTURE OVER
MISSOURI AND ILLINOIS THAT WILL ENTER CENTRAL INDIANA LATER THIS
MORNING...BUT BY THAT TIME TEMPS WILL BE INCREASING AGAIN...MAKING
IT DIFFICULT FOR MUCH SNOW ACCUMULATION. AS A RESULT...HAD TO
BRING THE RAIN FARTHER NORTH INTO THE CENTRAL TIER OF COUNTIES AS
WELL...REDUCING SNOWFALL AMOUNTS DOWN TO 1 TO 3 INCHES OVER THAT AREA
...AND THUS RESULTING IN THE REMOVAL OF CENTRAL COUNTIES FROM ANY
HEADLINES. THE WARM AIR ALSO RESULTED IN DOWNGRADING SOME OF THE
NORTHERN COUNTIES FROM A WARNING TO ADVISORY CRITERIA AS WELL.
MODELS ARE TRENDING TOWARD WARMER TEMPERATURES WITH HIGHS IN THE
LOW 40S ACROSS THE SOUTHERN COUNTIES...MID TO UPPER 30S OVER
CENTRAL COUNTIES...AND LOW TO MID 30S OVER THE NORTHERN COUNTIES.
THE REMAINING COUNTIES STILL IN ADVISORY AREA CAN EXPECT 3 TO 6
INCHES OF SNOWFALL BY TOMORROW MORNING.

CONFIDENCE REMAINS HIGH IN LARGE SNOW AMOUNTS ACROSS THE NORTHERN
MOST COUNTIES WHERE PRECIP IS EXPECTED TO REMAIN IN THE FORM OF
SNOW FOR DURATION OF EVENT. THERE WILL STILL BE CONCERN FOR
BLOWING SNOW ACROSS THOSE COUNTIES AS WELL LATER TODAY AND
TONIGHT. EAST WINDS WILL BE SUSTAINED AT 10 TO 20 MPH WITH GUSTS
UP TO 35 MPH THIS AFTERNOON. THEY WILL THEN BECOME NORTHERLY AT 15
TO 20 MPH TONIGHT...GUSTING TO 35 MPH. BITTER COLD AIR WILL BE
FILTERING INTO THE AREA BY THAT POINT TOO...RESULTING IN WIND
CHILLS FROM -1 TO 9 DEGREES ACROSS THE NORTHERN COUNTIES...TO
TEENS OVER THE SOUTHERN COUNTIES.


&&

.SHORT TERM /TOMORROW THROUGH TUESDAY NIGHT/...

ISSUED AT 427 AM EST SUN FEB 1 2015

SYSTEM WILL PUSH TO THE EAST BY TOMORROW MORNING WITH JUST A FEW
LINGERING SNOW SHOWERS OVER EASTERN PORTIONS OF CENTRAL INDIANA
THROUGH THE MORNING HOURS. IN ADDITION...LIGHT LAKE EFFECT SNOW
SHOWERS WILL BE POSSIBLE OVER THE NORTH/NORTHWESTERN COUNTIES ON
MONDAY MORNING...BUT ACCUMULATIONS WILL BE MINIMAL. DAYTIME HIGHS
FOR MONDAY HAVE ALSO TRENDED WARMER WITH READINGS IN THE UPPER
TEENS TO UPPER 20S. MONDAY NIGHT STILL LOOKS TO BE FRIGID THOUGH
WITH LESS CLOUD COVER...OVERNIGHT LOWS WILL RANGE FROM THE SINGLE
DIGITS ACROSS THE NORTH...TO TEENS ELSEWHERE.

THE MAIN FOCUS OF THE SHORT TERM PERIOD IS ACTUALLY AT THE VERY
END OF THE PERIOD. DRY CONDITIONS WILL PERSIST THROUGH
TUESDAY...BUT A COLD FRONT AND WEAK WAVE ALOFT WILL BRING SNOW
CHANCES FOR TUESDAY NIGHT. AS OF NOW...ACCUMULATIONS APPEAR
MINIMAL.


&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 010900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST SUN FEB 1 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ035>037-
039>043.

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
038.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 010842
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SUN FEB 1 2015

.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 010900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST SUN FEB 1 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 010842
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SUN FEB 1 2015

.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF THE
MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER WITH
THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 010900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST SUN FEB 1 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 010830
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SUN FEB 1 2015

.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
THE ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF
THE MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER
WITH THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 010900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST SUN FEB 1 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 010830
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SUN FEB 1 2015

.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
ISSUED AT 330 AM EST SUN FEB 1 2015

A QUICK MOVING UPPER WEAK WAVE WILL MOVE ACROSS OUR REGION TUESDAY
NIGHT FOLLOWED BY ANOTHER ONE WEDNESDAY AFTERNOON AND EVENING.
MODELS INDICATE A COLD FRONT WILL PUSH SOUTH ACROSS OUR REGION.
RAISED POPS SOME WEDNESDAY EVENING AS BOTH THE GEMNH AND 00Z EURO
INDICATE SIGNIFICANT PRECIP TWILL FALL WEDNESDAY EVENING...WHILE
THE ALSO GFS HAS IT WEDNESDAY EVENING ACROSS OUR SOUTH HALF.  ALL OF
THE MODELS ARE SIMILAR...WITH THE GFS BEING ABOUT 6 HOURS QUICKER
WITH THIS 2ND SHORT WAVE AND PRECIP.

ARCTIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT AND MOVE
EAST ACROSS OUR REGION THURSDAY NIGHT. LOWERED TEMPERATURES A LITTLE
ACROSS OUR NORTH THURSDAY NIGHT DUE TO GOOD RADIATIONAL COOLING AND
SOME SNOW COVER THERE.   FRIDAY WILL BE DRY AND COLD...WHILE
SATURDAY IS DRY AND WARMER AS SOUTHERLY FLOW INCREASES ACROSS OUR
REGION AHEAD OF THE NEXT COLD FRONT.  MOST MODELS INDICATE MIXED
PRECIP WILL RETURN FOR THE 2ND HALF OF NEXT WEEKEND AS THE NEXT COLD
FRONT MOVES IN.

&&

.AVIATION /DISCUSSION FOR THE 010900Z KIND TAF UPDATE/...
ISSUED AT 330 AM EST SUN FEB 1 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIWX 010636
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
136 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 645 PM EST SAT JAN 31 2015

NO SGFNT CHANGES TO EARLIER ZONES ATTM. PRECIP LIFTING NE TOWARD
THE AREA BEING FORCED BY WK LEAD SHRTWV MOVG INTO THE UPR MS
VALLEY/MIDWEST. ALL RAIN UPSTREAM ACROSS IL ATTM BUT AMDAR
SOUNDINGS EAST OF CHICAGO SUGGEST A PROFILE SUPPORTIVE OF SNOW.
MAINTAINED GOING MIXED PRECIP WX GRIDS ACROSS SWRN PORTION OF THE
CWA THIS EVE... WITH JUST SNOW ACROSS THE REST OF THE AREA. 18Z
MODELS CONT TO SUPPORT FCST OF A MAJOR WINTER STORM IMPACTING THE
CWA LATE TONIGHT THROUGH SUNDAY NIGHT AS MAIN UPR TROF DIGS SE
INTO THE MIDWEST PRECEDED BY STRONG MOISTURE TRANSPORT FROM THE SW
AND ACCOMPANIED BY A DEEPENING SFC LOW MOVG EAST FROM KS THROUGH
THE OH VALLEY RESULTING IN INCREASING WINDS AND SGFNT DRIFTING
SNOW FOR THE LATTER HALF OF THE EVENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 010636
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
136 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 645 PM EST SAT JAN 31 2015

NO SGFNT CHANGES TO EARLIER ZONES ATTM. PRECIP LIFTING NE TOWARD
THE AREA BEING FORCED BY WK LEAD SHRTWV MOVG INTO THE UPR MS
VALLEY/MIDWEST. ALL RAIN UPSTREAM ACROSS IL ATTM BUT AMDAR
SOUNDINGS EAST OF CHICAGO SUGGEST A PROFILE SUPPORTIVE OF SNOW.
MAINTAINED GOING MIXED PRECIP WX GRIDS ACROSS SWRN PORTION OF THE
CWA THIS EVE... WITH JUST SNOW ACROSS THE REST OF THE AREA. 18Z
MODELS CONT TO SUPPORT FCST OF A MAJOR WINTER STORM IMPACTING THE
CWA LATE TONIGHT THROUGH SUNDAY NIGHT AS MAIN UPR TROF DIGS SE
INTO THE MIDWEST PRECEDED BY STRONG MOISTURE TRANSPORT FROM THE SW
AND ACCOMPANIED BY A DEEPENING SFC LOW MOVG EAST FROM KS THROUGH
THE OH VALLEY RESULTING IN INCREASING WINDS AND SGFNT DRIFTING
SNOW FOR THE LATTER HALF OF THE EVENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 010636
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
136 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 645 PM EST SAT JAN 31 2015

NO SGFNT CHANGES TO EARLIER ZONES ATTM. PRECIP LIFTING NE TOWARD
THE AREA BEING FORCED BY WK LEAD SHRTWV MOVG INTO THE UPR MS
VALLEY/MIDWEST. ALL RAIN UPSTREAM ACROSS IL ATTM BUT AMDAR
SOUNDINGS EAST OF CHICAGO SUGGEST A PROFILE SUPPORTIVE OF SNOW.
MAINTAINED GOING MIXED PRECIP WX GRIDS ACROSS SWRN PORTION OF THE
CWA THIS EVE... WITH JUST SNOW ACROSS THE REST OF THE AREA. 18Z
MODELS CONT TO SUPPORT FCST OF A MAJOR WINTER STORM IMPACTING THE
CWA LATE TONIGHT THROUGH SUNDAY NIGHT AS MAIN UPR TROF DIGS SE
INTO THE MIDWEST PRECEDED BY STRONG MOISTURE TRANSPORT FROM THE SW
AND ACCOMPANIED BY A DEEPENING SFC LOW MOVG EAST FROM KS THROUGH
THE OH VALLEY RESULTING IN INCREASING WINDS AND SGFNT DRIFTING
SNOW FOR THE LATTER HALF OF THE EVENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 010636
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
136 AM EST SUN FEB 1 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 645 PM EST SAT JAN 31 2015

NO SGFNT CHANGES TO EARLIER ZONES ATTM. PRECIP LIFTING NE TOWARD
THE AREA BEING FORCED BY WK LEAD SHRTWV MOVG INTO THE UPR MS
VALLEY/MIDWEST. ALL RAIN UPSTREAM ACROSS IL ATTM BUT AMDAR
SOUNDINGS EAST OF CHICAGO SUGGEST A PROFILE SUPPORTIVE OF SNOW.
MAINTAINED GOING MIXED PRECIP WX GRIDS ACROSS SWRN PORTION OF THE
CWA THIS EVE... WITH JUST SNOW ACROSS THE REST OF THE AREA. 18Z
MODELS CONT TO SUPPORT FCST OF A MAJOR WINTER STORM IMPACTING THE
CWA LATE TONIGHT THROUGH SUNDAY NIGHT AS MAIN UPR TROF DIGS SE
INTO THE MIDWEST PRECEDED BY STRONG MOISTURE TRANSPORT FROM THE SW
AND ACCOMPANIED BY A DEEPENING SFC LOW MOVG EAST FROM KS THROUGH
THE OH VALLEY RESULTING IN INCREASING WINDS AND SGFNT DRIFTING
SNOW FOR THE LATTER HALF OF THE EVENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM EST SUN FEB 1 2015

LEAD UPPER LEVEL SHORT WAVE HAS ALLOWED LIGHT SNOW TO OVERSPREAD
TERMINALS OVER PAST SEVERAL HOURS...AND WITH ISENTROPIC UPGLIDE
AND LOW LEVEL FGEN FORCING INCREASING OVER THE NEXT SEVERAL
HOURS....SNOW INTENSITY SHOULD PICK UP...PARTICULARLY TOWARD
DAYBREAK. AN EXTENDED PERIOD OF LIFR CONDITIONS EXPECTED AS POTENT
UPPER LEVEL SYSTEM BEGINS TO APPROACH MID MS RIVER VALLEY ON
SUNDAY WITH PERIODS OF HEAVY SNOW SUNDAY/SUNDAY EVENING BEFORE
DIMINISHING. DEEPENING SFC REFLECTION TRACKING SOUTH OF THE AREA
WILL ALLOW NORTHEAST WINDS TO INCREASE WITH SIGNIFICANT BLOWING
AND DRIFTING SNOW AND REDUCED VISIBILITIES. SNOW TO WIND DOWN IN
INTENSITY TOWARD THE END OF THIS FORECAST VALID PERIOD...ALTHOUGH
GUSTY NORTHEAST WINDS TO 25 TO 30 KNOTS WILL RESULT IN CONTINUED
BLOWING SNOW THROUGH END OF THE FORECAST PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR OHZ001-002-004-
     005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 010437
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1135 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1135 PM EST SAT JAN 31 2015

LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 010437
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1135 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1135 PM EST SAT JAN 31 2015

LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 010437
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1135 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1135 PM EST SAT JAN 31 2015

LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 010437
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1135 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1135 PM EST SAT JAN 31 2015

LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 010437
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1135 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010600Z TAFS/...
ISSUED AT 1135 PM EST SAT JAN 31 2015

LOWER CONFIDENCE IN THE FORECAST THAN USUAL WITH RESPECT TO
PRECIPITATION TYPE AND RESULTANT VISIBILITY RESTRICTIONS AS MODEL
DATA SUGGEST CRITICAL THICKNESSES FOR PRECIPITATION TYPE WILL BE
STRADDLING THE FORECAST AREA.

INITIAL BAND OF LIFT CURRENTLY MOVING INTO THE NORTHERN ZONES AT
THIS TIME IS EXPECTED TO CONTINUE TO PUSH OFF TO THE NORTH. SHORT
TERM MODELS SUGGEST THERE MAY BE ANOTHER AREA OF ENHANCED LIFT
AROUND 010800Z-011200Z...SO PRECIPITATION MAY TEMPORARILY INCREASE
AROUND THAT TIME. THICKNESSES HOLD ABOUT STEADY OVERNIGHT...SO
APPEARS KBMG WILL BE PREDOMINATELY RAIN...WHILE KLAF WILL BE MOSTLY
SNOW. KIND/KHUF LOOKS TO BE NEAR THE TRANSITION ZONE...SO EXPECTING
MIXED PRECIPITATION IN THOSE AREAS. THE MOST LIKELY AREAS FOR IFR
VISIBILITY RESTRICTIONS OVERNIGHT WILL BE IN THE KLAF/KHUF/KIND
AREAS WHERE THERE IS A HIGHER LIKELIHOOD OF SNOW.

STRONGER LIFT BEGINS MOVING INTO THE AREA BY THE LATE MORNING HOURS
ON SUNDAY...SO PRECIPITATION SHOULD BECOME MORE WIDESPREAD AND
HEAVIER BY THAT TIME. LATEST MODEL GUIDANCE INDICATES THICKNESSES
MAY RISE AFTER SUNRISE SUNDAY...WHICH WOULD TREND PRECIPITATION TYPE
MORE TOWARDS RAIN. FOR NOW...WILL HOLD WITH THE PREVIOUS IDEA OF
MAINLY RAIN AT KBMG...MIXED AT KIND/KHUF...AND MAINLY SNOW AT KLAF.
BY MIDDAY SUNDAY...APPEARS ALL TAF SITES WILL BE AT IFR OR LOWER
EITHER DUE TO CEILING OR VISIBILITY.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 100-130 DEGREES
BY LATE MORNING SUNDAY AS LOW APPROACHES...WITH SPEEDS GENERALLY
10-13 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 010305
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1005 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS












000
FXUS63 KIND 010305
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1005 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS











000
FXUS63 KIND 010305
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1005 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS











000
FXUS63 KIND 010305
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1005 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 1005 PM EST SAT JAN 31 2015

GIVEN THE WAY THINGS HAVE EVOLVED TONIGHT AND THE STATE OF SHORT
TERM MODEL DATA HAVE BUMPED THE RAIN CHANCES A BIT FURTHER NORTH
OVERNIGHT. WILL MAKE NO MAJOR CHANGES TO AMOUNTS AT THIS TIME
AS THEY WILL BE EXTREMELY SENSITIVE TO TINY TEMPERATURE CHANGES AND
NOT YET READY TO MAKE WHOLESALE ADJUSTMENTS. PREVIOUS DISCUSSION
FOLLOWS.

ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS












000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 010229
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
927 PM EST SAT JAN 31 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010300Z KIND TAF UPDATE/...
ISSUED AT 927 PM EST SAT JAN 31 2015

RADAR INDICATES ONE OR TWO MORE BANDS OF PRECIPITATION SHOULD PASS
OVER THE KIND TERMINAL OVER THE NEXT FEW HOURS. MOST OF THE
PRECIPITATION HAS BEEN SNOW...BUT DUAL POL SUGGESTS A MIX OR CHANGE
OVER TO RAIN IS POSSIBLE WITHIN THE NEXT HOUR OR SO.

SURFACE WINDS ARE IN THE PROCESS OF BACKING AROUND TO THE SOUTHEAST.
DROPPED WIND FORECAST TO LESS THAN 7 KTS FOR THE REST OF THE NIGHT.

PREVIOUS DISCUSSION FOLLOWS.

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 010035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
735 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 010035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
735 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS





000
FXUS63 KIND 010035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
735 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS





000
FXUS63 KIND 010035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
735 PM EST SAT JAN 31 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ISSUED AT 735 PM EST SAT JAN 31 2015

ADDED A CHANCE OF SLEET TO THE GRIDS AS SLEET HAS BEEN MIXING IN
WITH THE PRECIP AT LEAST INITIALLY. WILL CARRY THAT THROUGH THE
FIRST FEW HOURS OF THE EVENING AND THEN DROP IT. REMAINDER OF
FORECAST IN EXCELLENT SHAPE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...
ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIWX 312356
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
656 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 645 PM EST SAT JAN 31 2015

NO SGFNT CHANGES TO EARLIER ZONES ATTM. PRECIP LIFTING NE TOWARD
THE AREA BEING FORCED BY WK LEAD SHRTWV MOVG INTO THE UPR MS
VALLEY/MIDWEST. ALL RAIN UPSTREAM ACROSS IL ATTM BUT AMDAR
SOUNDINGS EAST OF CHICAGO SUGGEST A PROFILE SUPPORTIVE OF SNOW.
MAINTAINED GOING MIXED PRECIP WX GRIDS ACROSS SWRN PORTION OF THE
CWA THIS EVE... WITH JUST SNOW ACROSS THE REST OF THE AREA. 18Z
MODELS CONT TO SUPPORT FCST OF A MAJOR WINTER STORM IMPACTING THE
CWA LATE TONIGHT THROUGH SUNDAY NIGHT AS MAIN UPR TROF DIGS SE
INTO THE MIDWEST PRECEDED BY STRONG MOISTURE TRANSPORT FROM THE SW
AND ACCOMPANIED BY A DEEPENING SFC LOW MOVG EAST FROM KS THROUGH
THE OH VALLEY RESULTING IN INCREASING WINDS AND SGFNT DRIFTING
SNOW FOR THE LATTER HALF OF THE EVENT.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 633 PM EST SAT JAN 31 2015

CDFNT DROPPING SOUTH ACROSS THE GRTLKS WILL MOVE THROUGH THE
TERMINALS TONIGHT. WK SHRTWV LIFTING INTO THE UPR MIDWEST AHEAD OF
MAIN SYSTEM WILL SPREAD A BAND OF SNOW WITH IFR CONDITIONS TO THE
TERMINALS BY LATE EVE. DEEPENING LOW PRESSURE SYSTEM WILL TRACK FROM
ERN KS SUNDAY MORNING TO SRN INDIANA SUNDAY EVENING. SNOW WILL
BECOME HEAVIER AND E-NE WINDS STRONGER DURING THE DAY AS THE LOW
APPROACHES RESULTING IN LIFR AVIATION CONDITIONS WITH ACCUMULATING
SNOW AND BLSN.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...JT
SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 312340
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
640 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A COLD FRONT WILL MOVE SOUTH FROM THE GREAT LAKES TO THE OHIO
VALLEY TONIGHT. A STRENGTHENING LOW PRESSURE SYSTEM WILL MOVE EAST
ALONG THE FRONT THROUGH THE OHIO VALLEY SUNDAY AND SUNDAY NIGHT.
SNOW WILL OVERSPREAD OUR AREA TONIGHT AND BECOME HEAVY ON SUNDAY.
WINDS WILL INCREASE SUNDAY AND SUNDAY NIGHT CAUSING BLOWING AND
DRIFTING SNOW MAKING TRAVEL DIFFICULT...IF NOT IMPOSSIBLE. LOWS
TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 633 PM EST SAT JAN 31 2015

CDFNT DROPPING SOUTH ACROSS THE GRTLKS WILL MOVE THROUGH THE
TERMINALS TONIGHT. WK SHRTWV LIFTING INTO THE UPR MIDWEST AHEAD OF
MAIN SYSTEM WILL SPREAD A BAND OF SNOW WITH IFR CONDITIONS TO THE
TERMINALS BY LATE EVE. DEEPENING LOW PRESSURE SYSTEM WILL TRACK FROM
ERN KS SUNDAY MORNING TO SRN INDIANA SUNDAY EVENING. SNOW WILL
BECOME HEAVIER AND E-NE WINDS STRONGER DURING THE DAY AS THE LOW
APPROACHES RESULTING IN LIFR AVIATION CONDITIONS WITH ACCUMULATING
SNOW AND BLSN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIND 312234
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
532 PM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312234
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
532 PM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 010000Z TAFS/...
ISSUED AT 532 PM EST SAT JAN 31 2015

LOWER CONFIDENCE THAN USUAL TONIGHT AS MODEL DATA SUGGEST CRITICAL
THICKNESSES FOR PRECIPITATION TYPE WILL BE STRADDLING THE FORECAST
AREA. DIFFERENT PRECIPITATION TYPES WILL HAVE AN IMPACT ON
VISIBILITY RESTRICTIONS.

INITIAL BAND OF LIFT EXPECTED TO MOVE NORTHEAST ACROSS THE AREA
THROUGH ABOUT 010600Z OR SO. APPEARS KBMG WILL BE PREDOMINATELY
RAIN...WHILE KLAF WILL BE MOSTLY SNOW. KIND/KHUF LOOKS TO BE NEAR
THE TRANSITION ZONE...SO EXPECTING MIXED PRECIPITATION IN THOSE
AREAS. FOR THE MOST PART...THE RAIN OR RAIN/SNOW MIX WILL BE LIGHT
ENOUGH TO KEEP VISIBILITY RESTRICTIONS ABOVE IFR AT KBMG/KHUF/KIND.
A PERIOD OF IFR/LIFR VISIBILITY RESTRICTIONS MORE LIKELY IN KLAF
WHERE MOSTLY SNOW IS EXPECTED.

PRECIPITATION THREAT SHOULD DIMINISH TOWARDS/AFTER 010600Z AT THE
MORE SOUTHERN TAF SITES AS LIFT MOVES OFF TO THE NORTH. MORE
QUESTIONABLE WHETHER THERE WILL BE A BREAK IN KLAF LATER TONIGHT AS
BAND OF LIFT WILL EVENTUALLY SLOW DOWN AND BEGIN TO PIVOT BACK TO
THE SOUTH. NOT SURE AT THIS TIME WHETHER THAT POINT WILL BE OVER OR
NORTH OF KLAF. FOR NOW...WILL KEEP PERIODS OF IFR/LIFR IN KLAF
THROUGHOUT THE NIGHT...WITH A TENDENCY TOWARDS LOWER CONDITIONS AS
SUNRISE APPROACHES.

SURFACE WINDS EXPECTED TO GRADUALLY BACK AROUND TO 120-140 DEGREES
BY THE PRE DAWN HOURS AS LOW PRESSURE APPROACHES...BUT SPEEDS SHOULD
GENERALLY BE AT OR BELOW 7 KTS TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS











000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 312205 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
458 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTIES!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NORTHERN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION
WELL TO THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
AN EXTENDED PERIOD SUNDAY AFTERNOON.

THE LOW WILL BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING
AND COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY
SUNDAY NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL
PICK UP STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING
TIGHT PRESSURE GRADIENT WITH THIS SYSTEM AND THE SURFACE WINDS
ARE EXPECTED TO GUST UPWARDS OF 30 MPH. THIS WILL HAVE A NEGATIVE
IMPACT ON TRAVEL...AT LEAST FOR THE NORTHERN COUNTIES IN THE
WINTER STORM WARNING AND ADVISORY AREAS AS BLOWING SNOW BECOMES
AN ISSUE WHICH CAN REDUCE VISIBILITIES...IN ADDITION TO
PROBLEMATIC DRIFTING SNOW.

AS FOR TEMPERATURES DURING THIS PERIOD...GENERALLY STUCK WITH A
MOS BLEND BUT WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE
PRECIPITATION AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS
AND KNOCKED DOWN THESE TEMPERATURES A NOTCH OR TWO FOR THE SAME
REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY N/NW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 312137
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
437 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 312137
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
437 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 312137
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
437 PM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 435 PM EST SAT JAN 31 2015

A SIGNIFICANT STORM SYSTEM WILL IMPACT CENTRAL INDIANA STARTING
TONIGHT...AND CONTINUING THROUGH SUNDAY BEFORE FINALLY COMING TO AN
END EARLY MONDAY MORNING. AS THIS SYSTEM PUSHES AWAY FROM THE AREA
ON MONDAY...FRIGID TEMPERATURES WILL FILTER BACK INTO THE REGION.
THEN AFTER A RETURN TO NORMAL TEMPERATURES BY MID-WEEK...THE BITTER
COLD CONDITIONS WILL RETURN ONCE AGAIN FOR THE END OF THE WORK WEEK
IN THE WAKE OF A COLD FRONT MOVING THROUGH ON WEDNESDAY. THIS COLD
FRONT WILL ALSO BE RESPONSIBLE FOR WINTER PRECIPITATION FROM TUESDAY
NIGHT THROUGH WEDNESDAY NIGHT. COLD HIGH PRESSURE WILL BUILD BACK
OVER THE REGION FOR NEXT THURSDAY AND FRIDAY.

&&

.NEAR TERM /TONIGHT THROUGH SUNDAY NIGHT/...

ISSUED AT 435 PM EST SAT JAN 31 2015

FOCUS FOR THE NEXT 24 TO 36 HOURS IS THE STRONG LOW PRESSURE SYSTEM
DEVELOPING IN THE SOUTHERN PLAINS TONIGHT AND MOVING NORTHEAST INTO
THE OHIO VALLEY BY SUNDAY. FOR THE MOST PART...ALL THE 12Z MODELS
HAVE CONTINUED THE TREND OF PREVIOUS RUNS...WHICH TAKES THE LOW A
LITTLE FARTHER NORTHWARD. THIS IN TURN PULLS MORE WARM AIR INTO THE
REGION. AS STATED IN PREVIOUS FORECAST DISCUSSIONS...THERE WILL BE A
VERY SIGNIFICANT GRADIENT WITH REGARD TO SNOWFALL AMOUNTS ACROSS
CENTRAL INDIANA RANGING FROM LESS THAN AN INCH...POSSIBLY EVEN ZERO
TO A TRACE ACROSS THE FAR SOUTHERN COUNTIES...TO 9-12 INCHES ACROSS
THE NORTH IN CARROLL AND HOWARD COUNTY!

AHEAD OF THE LOW...ISENTROPIC LIFT DEVELOPS TONIGHT ALLOWING FOR A
MIXTURE OF SNOW AND POSSIBLY SOME RAIN TO OVERSPREAD THE AREA. A
COUPLE OF INCHES OF SNOW ACCUMULATION WILL BE POSSIBLE ACROSS THE
NRN COUNTIES TONIGHT...WITH VERY LITTLE IF ANY ACCUMULATION WELL TO
THE SOUTH OF THE I-70 CORRIDOR.

TEMPERATURES WILL WARM AHEAD OF THE LOW SUNDAY...ALLOWING FOR RAIN
TO MIX IN WITH SNOW...OR EVEN BECOME THE PREDOMINANT PRECIPITATION
TYPE FOR THE SOUTHERN HALF OF THE FORECAST AREA...ESPECIALLY DURING
A PERIOD SUNDAY AFTERNOON.

THE LOW BEGIN TO MOVE EAST OF THE REGION BY SUNDAY EVENING AND
COLDER AIR WILL THEN QUICKLY WORK IN ON THE BACKSIDE OF THE
SYSTEM...THUS CHANGING ALL THE PRECIPITATION BACK TO SNOW BY SUNDAY
NIGHT. IN ADDITION TO THE PRECIPITATION...THE WINDS WILL PICK UP
STARTING LATE SUNDAY AFTERNOON THANKS TO A STRENGTHENING TIGHT
PRESSURE GRADIENT WITH THIS SYSTEM AND WINDS WILL GUST UPWARDS OF 30
MPH. THIS WILL HAVE A NEGATIVE IMPACT ON TRAVEL...AT LEAST FOR THE
NORTHERN COUNTIES IN THE WINTER STORM WARNING AND ADVISORY AS
BLOWING SNOW BECOMES AN ISSUE WHICH CAN REDUCE VISIBILITIES AND ALSO
DRIFTING SNOW.

AS FOR TEMPERATURE DURING THIS PERIOD...GENERALLY STUCK WITH MOS BUT
WENT SLIGHTLY WARMER AT NIGHT TO ACCOUNT FOR ALL THE PRECIPITATION
AND CLOUD COVER AND WAS MORE CONSERVATIVE WITH HIGHS AND KNOCKED
DOWN HIGHS TEMPERATURES A NOTCH OR TWO FOR SAME REASONING.

&&

.SHORT TERM /MONDAY THROUGH TUESDAY/...

ISSUED AT 435 PM EST SAT JAN 31 2015

THE WINTER STORM WILL BE COMING TO AN END ON MONDAY MORNING...WITH
SOME LIGHT ADDITIONAL SNOW ACCUMULATIONS POSSIBLE BETWEEN 12 TO 18Z
MAINLY ACROSS THE EASTERN COUNTIES OF THE FORECAST AREA AS THE LOW
ACCELERATES AWAY FROM THE REGION. ON THE BACK SIDE OF THE
STRENGTHENING SURFACE LOW...GUSTY NNW FLOW WILL LEAD TO STRONG COLD
ADVECTION AND HIGH TEMPERATURES FOR MONDAY WILL BE WELL BELOW NORMAL
RANGING FROM THE LOW TEENS (NORTH) TO LOW 20S (SOUTH). STRONG
NORTHERLY WINDS WILL ALLOW WIND CHILLS TO DROP TO BELOW ZERO ON
MONDAY AND TUESDAY MORNINGS. HIGH PRESSURE IS QUICK TO REESTABLISH
ITSELF ACROSS THE AREA FOR THE BEGINNING OF THE WORK WEEK AND BY
TUESDAY HIGHS WILL BE BACK IN THE 30S WHICH IS NORMAL FOR THIS TIME
OF YEAR.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 7 AM EST MONDAY FOR INZ021-028>031-
035>042.

WINTER WEATHER ADVISORY UNTIL 7 AM EST MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIWX 312130
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
430 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. SIGNIFICANT HEAVY SNOW WITH
INCREASED BLOWING AND DRIFTING SNOW...ESPECIALLY SUNDAY AFTERNOON
INTO SUNDAY NIGHT WILL MAKE TRAVEL DIFFICULT...IF NOT IMPOSSIBLE.
LOWS TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETERIORATION INTO LONG LIVED LIFR EVENT
DURING DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO
MULTI MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY.
LATER FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL
BEGIN TO BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 312130
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
430 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. SIGNIFICANT HEAVY SNOW WITH
INCREASED BLOWING AND DRIFTING SNOW...ESPECIALLY SUNDAY AFTERNOON
INTO SUNDAY NIGHT WILL MAKE TRAVEL DIFFICULT...IF NOT IMPOSSIBLE.
LOWS TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETERIORATION INTO LONG LIVED LIFR EVENT
DURING DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO
MULTI MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY.
LATER FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL
BEGIN TO BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA










000
FXUS63 KIWX 312130
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
430 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. SIGNIFICANT HEAVY SNOW WITH
INCREASED BLOWING AND DRIFTING SNOW...ESPECIALLY SUNDAY AFTERNOON
INTO SUNDAY NIGHT WILL MAKE TRAVEL DIFFICULT...IF NOT IMPOSSIBLE.
LOWS TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETERIORATION INTO LONG LIVED LIFR EVENT
DURING DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO
MULTI MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY.
LATER FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL
BEGIN TO BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 312130
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
430 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 427 PM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. SIGNIFICANT HEAVY SNOW WITH
INCREASED BLOWING AND DRIFTING SNOW...ESPECIALLY SUNDAY AFTERNOON
INTO SUNDAY NIGHT WILL MAKE TRAVEL DIFFICULT...IF NOT IMPOSSIBLE.
LOWS TONIGHT WILL PRIMARILY BE IN THE 20S..WITH LITTLE IF ANY
TEMPERATURE RISE ON SUNDAY. MUCH COLDER TEMPERATURES ARE IN STORE
FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 418 PM EST SAT JAN 31 2015

INCREASED CONFIDENCE THROUGHOUT THE DAY WRT QUITE SIGNIFICANT
WINTER WX EVENT TARGETING CWA. WV IMAGERY AND UPSTREAM
PRECONDITIONING SETS STAGE FOR DEEP WALL OF MOISTURE
ADVECTION/MFLUX CONVERGNECE FOR PROLONGED PERIOD INTO CWA. PWAT
VALUES OVR CNTL PLAINS ON ORDER OF 200-300 PERCENT OF NORMAL.
EXPANSIVE BREADTH OF BULK MOISTURE WITH CONSISTENT 0.5 TO 0.65
INCH PWAT PIVOTING SLOWLY THROUGH SRN TWO THIRDS CWA THROUGH THE
EVENT...WITH CULMINATING 0.9 INCH PWAT TAP ACRS SWRN OH SUN
EVENING...ON ORDER OF 2 SD ABOVE CLIMATOLOGICAL
MEAN...IMPLICATING THIS EVENT WITH HIGH POTENTIAL FOR BEING SIG
OUTLIER TO CLIMATOLOGY. HIGHLY CONFLUENT/RAMPING I285/I290K ISENT
UPGLIDE OVER SERN MISSOURI THIS EVENING...TO 50-55KT LOW LEVEL
JET ENTERING FAR SRN IN BY SUN AFTN. STRONG TRAILING MID LEVEL
DEFORMATION WITH PROLONGED PERIOD OF SYSTEM RELATIVE ISENT
UPGLIDE PERSISTING THROUGH 06 UTC MONDAY...LENDING TO EXT IN TIME
TO ERN CWA UNTIL 12 UTC. BLSN TO IMPACT HIGHLY...ESPCLY ACRS E-W
ROADS ACRS NRN CWA WHERE EVENT SLR TO BE HIEST. 7H CLOSED LOW
TRACK ALONG WITH TROWAL/DEFORMATION AXIS PORTENDS TO AXIS OF
HEAVIEST SNOW FROM ABOUT KNOX TO TOLEDO...WITH A FAIRLY BROAD
20-30 MILES EITHER SIDE...BEFORE SIG SNOW TOTAL GRADIENTS FOUND.
EXTREME DEEPENING WITH SENSATIONAL MID TROPOPHERIC HEIGHT FALLS
RAMPING IN EXCESS OF 200M/12 HR THROUGH AS IT TRACKS EWD THROUGH
MID/OHIO VALLEY SUN NIGHT...AND MORE STRONGLY CLOSED 7H TRACK AND
PRESENCE OF DECREASED STATIC STATIC STABILITY SUN AFTERNOON INTO
EARLY EVENING GIVES CONCERN FOR POSSIBLE MESOBANDING LEADING TO
AMOUNTS UPWARDS OF 15 INCHES THROUGH FAR NRN IN ALONG NORTH OF
ROUTE 30...TO SCNTL LWR MI/EXTREME NWRN OH. 18 UTC NAM EVEN
GENERATING POCKETS OF 30-80 J/KG MUCAPE ACRS NRN TWO THIRDS CWA
SUNDAY INTO EARLY SUN NIGHT...PERHAPS POINTING TO CONVECTIVE
ELEMENTS...COMMENSURATE SNOWFALL RATES WOULD THEN LIKELY PEAK AT
2-4 INCHES PER HOUR...ALBEIT BRIEFLY.

FROM 03/09 UTC SREF WITH ITS INCREASED CLUSTERING OVER NRN/CNTL
CWA TO 12/18 UTC MODEL SUITE CONSISTENT MESSAGE APPEARS.
REMARKABLY EVEN THE LOWEST OUTLIER IN 09 UTC SREF MEMBERS ACRS
NRN CWA PEGGED AT 8-10 INCHES...WITH CONSENSUS MEANS ABOUT 6-8
INCHES HIR. IDYLLIC DEEP DGZ ALONG NORTH OF ROUTE 30...WITH
NAM/ARW DEPICTING 7-9KFT DGZ LAYER. STILL MINOR CONCERN WITH
SUPERSATURATION ABOVE TO INTRODUCE PLATES/NEEDLES FOR FINER SIZED
FLAKES...BUT CONCEDE QPF/DYNAMICS OF SYSTEM TO OFFSET. KSBN TO
KJYM MOST CONSTERNATION ACRS FAR SWRN/SRN INDIAN COUNTIES WHERE
INITIAL WARM 0-2KM WET BULB INTRUSION LENDING POSSIBLE MIX AT
ONSET AND LESSENED SLR THEREAFTER WITH PARTIAL MELT.

&&

.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 418 PM EST SAT JAN 31 2015

ONE OR MORE LAKE EFFECT SNOW BANDS WILL RESIDE NEAR OR JUST WEST
OF THE FORECAST AREA ACROSS LAKE AND PORTER COUNTIES. HI RES
MODELS TREND THIS FEATURE SLOWLY EAST THROUGH THE MORNING AND
THEN DISSIPATE AS IT SHIFTS ACROSS NORTHERN INDIANA. DESPITE WHAT
SHOULD BE A WELL FORMED BAND THAT MAY EXTEND THE LONG AXIS OF LK
MI...INVERSION HGTS WILL BE LOWERING AND MSTR WILL BE SOMEWHAT
LIMITED. ALSO EXACT EVOLUTION OF THE BAND WILL BE DETERMINED BY
ANY POTENTIAL INTENSIFICATION OF THE SFC LOW AND ITS FINAL TRACK.
AS A RESULT HAVE NOT MADE MANY CHANGES OTHER THAN TO INCREASE
POPS SLIGHTLY IN FAR NW AREAS AND TRY TO BRING THE BAND SOMEWHAT
EAST BEFORE WEAKENING.

ALTHOUGH NO BIG SYSTEMS ARE DURING THE PERIOD...A WEAK SYSTEM
WILL DROP SE TOWARDS THE REGION TUESDAY INTO EARLY WEDNESDAY.
LIGHT SNOW WILL BE POSSIBLE WITH THIS FEATURE FOLLOWED BY ANOTHER
BRIEF SHOT OF COLD AIR BEFORE SOME MODERATION AGAIN LATE WEEK
INTO THE WEEKEND.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETERIORATION INTO LONG LIVED LIFR EVENT
DURING DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO
MULTI MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY.
LATER FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL
BEGIN TO BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING UNTIL 4 AM EST /3 AM CST/ MONDAY FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR MIZ081.

     WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR MIZ077>080.

OH...WINTER STORM WARNING FROM 10 PM THIS EVENING TO 7 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MURPHY
LONG TERM...FISHER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA










000
FXUS63 KIND 311957
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
257 PM EST SAT JAN 31 2015

.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-028>031-035>042.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 311957
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
257 PM EST SAT JAN 31 2015

.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...

ISSUED AT 251 PM EST SAT JAN 31 2015

THE EXTENDED TIMEFRAME IS CHARACTERIZED BY A COUPLE OF LIGHT SNOW
PRODUCING UPPER WAVES AND A COUPLE OF WELL BELOW NORMAL TEMPERATURE
DAYS BRACKETED BY A COUPLE SEASONAL DAYS.

A QUICK MOVING WEAK UPPER WAVE WILL MOVE ACROSS THE OHIO RIVER
VALLEY TUESDAY AFTERNOON THROUGH TUESDAY NIGHT...BRINGING LIGHT
SNOW CHANCES TO THE NORTHERN HALF OF CENTRAL INDIANA MAINLY ON
TUESDAY NIGHT. AFTER A COLD FRONT SLIDES SOUTHEAST THROUGH THE
FORECAST AREA WEDNESDAY...TEMPERATURES SOME 10 TO 15 DEGREES
BELOW NORMAL ARE EXPECTED INTO FRIDAY INCLUDING A RETURN OF
SINGLE DIGIT LOWS OVER PORTIONS OF CENTRAL INDIANA. ACCORDING TO
THE 12Z GFS...THE SECOND UPPER WAVE BEGINS TO AFFECT THE OHIO
RIVER VALLEY WEDNESDAY NIGHT WIPING A SWATH OF LIGHT SNOW ACROSS
PORTIONS OF SOUTHERN INDIANA. THERE IS SOME AMBIGUITY AS TO THE
EVOLUTION OF THIS SYSTEM...AS THE 12Z ECMWF SENDS THIS WEAK TROUGH
ACROSS THE NORTHERN PLAINS AND INTO THE AREA WEDNESDAY NIGHT AND
THURSDAY...PRODUCING VERY LITTLE ACROSS THE AREA. THIS STANDS IN
CONTRAST TO THE 12Z GFS DIGGING A MORE AMPLIFIED TROUGH ACROSS THE
CENTRAL AND SOUTHERN PLAINS DURING THE SAME TIMEFRAME. ACCOUNTED
FOR THIS LIGHT SNOW POSSIBILITY WITH SLIGHT CHANCE POP GENERALLY
ACROSS OUR SOUTHERN TWO TIER OF COUNTIES.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-028>031-035>042.

WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
MONDAY FOR INZ043>049.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM....MRD
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIWX 311722
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1222 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY
AFTERNOON AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND
MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE
FINE TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH
DIMINISHED AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF
WARM WET BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C
WET BULB PER KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A
PARTIAL MELT OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS
OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW
OVERSPREAD THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH
IMPACT SNOW EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE
LONG TERM SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT
FROM 00Z THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER
STORM WATCH IN EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR
THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH
SOME MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS
THIS MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE
NEXT FEW HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE
NORTHERN GREAT LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE
FAR NORTH...BUT MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST
THROUGH EARLY AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS
IS EXPECTED LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR
UPCOMING SNOW EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES.
HIGH TEMPERATURES THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER
THAN YESTERDAY INTO THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST
IMPACTS WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED
IN LONG TERM SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING
APPROACHES THE REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS
COMING TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING
SNOW. MOISTURE LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER
LEVELS WILL ARRIVE IN TANDEM AS THE NORTHERN STREAM SYSTEM AND
THE SOUTHERN STREAM PHASE. PRECIPITATION EFFICIENCY WITH THIS
SETUP SHOULD BE VERY GOOD. FOR THIS EVENT...FAVORED A GFS
SOLUTION. THE GFS HAS BEEN TRENDING TOWARD A SLOWER AND MORE
NORTHERN TRACK AND A RELATIVELY LONG DURATION EVENT. ALSO...THIS
GFS SEEMS TO BE HANDLING ALL OF THE SIGNIFICANT PARAMETERS FOR
THIS WINTER STORM REASONABLY WELL. THE 290K GARCIA/MIXING RATIO
METHOD RENDERS 8 TO 12 INCHES OF SNOW...WITH LESSER AMOUNTS OVER
FAR SOUTHERN LOWER MICHIGAN. STILL SOME UNCERTAINTY OVER THIS FAR
NORTHERN PORTION OF THE AREA GIVEN LOWER MIXING RATIOS AND A
GREATER CHANCE FOR DRY AIR ENTRAINMENT WITH LOW LEVEL/DRIER
NORTHEAST FLOW DURING THE SECOND HALF OF THE EVENT. THEREFORE...
AFTER COORDINATION WITH SURROUNDING OFFICES... KEPT LOWER
MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO THE NEXT
SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF
AND NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH
FT WAYNE AND LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8
INCHES OR MORE IS RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY
5 TO 6.5 YEARS. FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE
HAPPENS ONLY ONCE IN EVERY 15 TO 25 YEARS. GIVEN THESE
FACTORS...AND CONSIDERING THE ABOVE...KEPT ONGOING SNOWFALL
AMOUNTS CLOSE TO THE ONGOING/INHERITED AMOUNTS...WITH THE LATEST
THINKING THAT TOTAL SNOWFALL AMOUNTS FROM THIS STORM SHOULD RANGE
FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL IMPACTS WILL BE MOUNTING
SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING AND DRIFTING SNOW.
RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING GIVEN THE NEW AND
FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT SURFACE PRESSURE
GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD END FROM WEST
TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED ROADS WILL
LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING WELL BELOW
ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETEORATION INTO LONG LIVED LIFR EVENT DURING
DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO MULTI
MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY. LATER
FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL BEGIN TO
BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311722
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1222 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY
AFTERNOON AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND
MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE
FINE TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH
DIMINISHED AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF
WARM WET BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C
WET BULB PER KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A
PARTIAL MELT OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS
OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW
OVERSPREAD THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH
IMPACT SNOW EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE
LONG TERM SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT
FROM 00Z THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER
STORM WATCH IN EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR
THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH
SOME MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS
THIS MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE
NEXT FEW HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE
NORTHERN GREAT LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE
FAR NORTH...BUT MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST
THROUGH EARLY AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS
IS EXPECTED LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR
UPCOMING SNOW EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES.
HIGH TEMPERATURES THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER
THAN YESTERDAY INTO THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST
IMPACTS WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED
IN LONG TERM SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING
APPROACHES THE REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS
COMING TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING
SNOW. MOISTURE LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER
LEVELS WILL ARRIVE IN TANDEM AS THE NORTHERN STREAM SYSTEM AND
THE SOUTHERN STREAM PHASE. PRECIPITATION EFFICIENCY WITH THIS
SETUP SHOULD BE VERY GOOD. FOR THIS EVENT...FAVORED A GFS
SOLUTION. THE GFS HAS BEEN TRENDING TOWARD A SLOWER AND MORE
NORTHERN TRACK AND A RELATIVELY LONG DURATION EVENT. ALSO...THIS
GFS SEEMS TO BE HANDLING ALL OF THE SIGNIFICANT PARAMETERS FOR
THIS WINTER STORM REASONABLY WELL. THE 290K GARCIA/MIXING RATIO
METHOD RENDERS 8 TO 12 INCHES OF SNOW...WITH LESSER AMOUNTS OVER
FAR SOUTHERN LOWER MICHIGAN. STILL SOME UNCERTAINTY OVER THIS FAR
NORTHERN PORTION OF THE AREA GIVEN LOWER MIXING RATIOS AND A
GREATER CHANCE FOR DRY AIR ENTRAINMENT WITH LOW LEVEL/DRIER
NORTHEAST FLOW DURING THE SECOND HALF OF THE EVENT. THEREFORE...
AFTER COORDINATION WITH SURROUNDING OFFICES... KEPT LOWER
MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO THE NEXT
SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF
AND NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH
FT WAYNE AND LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8
INCHES OR MORE IS RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY
5 TO 6.5 YEARS. FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE
HAPPENS ONLY ONCE IN EVERY 15 TO 25 YEARS. GIVEN THESE
FACTORS...AND CONSIDERING THE ABOVE...KEPT ONGOING SNOWFALL
AMOUNTS CLOSE TO THE ONGOING/INHERITED AMOUNTS...WITH THE LATEST
THINKING THAT TOTAL SNOWFALL AMOUNTS FROM THIS STORM SHOULD RANGE
FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL IMPACTS WILL BE MOUNTING
SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING AND DRIFTING SNOW.
RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING GIVEN THE NEW AND
FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT SURFACE PRESSURE
GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD END FROM WEST
TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED ROADS WILL
LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING WELL BELOW
ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETEORATION INTO LONG LIVED LIFR EVENT DURING
DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO MULTI
MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY. LATER
FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL BEGIN TO
BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311722
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1222 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY
AFTERNOON AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND
MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE
FINE TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH
DIMINISHED AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF
WARM WET BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C
WET BULB PER KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A
PARTIAL MELT OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS
OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW
OVERSPREAD THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH
IMPACT SNOW EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE
LONG TERM SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT
FROM 00Z THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER
STORM WATCH IN EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR
THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH
SOME MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS
THIS MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE
NEXT FEW HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE
NORTHERN GREAT LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE
FAR NORTH...BUT MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST
THROUGH EARLY AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS
IS EXPECTED LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR
UPCOMING SNOW EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES.
HIGH TEMPERATURES THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER
THAN YESTERDAY INTO THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST
IMPACTS WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED
IN LONG TERM SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING
APPROACHES THE REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS
COMING TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING
SNOW. MOISTURE LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER
LEVELS WILL ARRIVE IN TANDEM AS THE NORTHERN STREAM SYSTEM AND
THE SOUTHERN STREAM PHASE. PRECIPITATION EFFICIENCY WITH THIS
SETUP SHOULD BE VERY GOOD. FOR THIS EVENT...FAVORED A GFS
SOLUTION. THE GFS HAS BEEN TRENDING TOWARD A SLOWER AND MORE
NORTHERN TRACK AND A RELATIVELY LONG DURATION EVENT. ALSO...THIS
GFS SEEMS TO BE HANDLING ALL OF THE SIGNIFICANT PARAMETERS FOR
THIS WINTER STORM REASONABLY WELL. THE 290K GARCIA/MIXING RATIO
METHOD RENDERS 8 TO 12 INCHES OF SNOW...WITH LESSER AMOUNTS OVER
FAR SOUTHERN LOWER MICHIGAN. STILL SOME UNCERTAINTY OVER THIS FAR
NORTHERN PORTION OF THE AREA GIVEN LOWER MIXING RATIOS AND A
GREATER CHANCE FOR DRY AIR ENTRAINMENT WITH LOW LEVEL/DRIER
NORTHEAST FLOW DURING THE SECOND HALF OF THE EVENT. THEREFORE...
AFTER COORDINATION WITH SURROUNDING OFFICES... KEPT LOWER
MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO THE NEXT
SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF
AND NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH
FT WAYNE AND LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8
INCHES OR MORE IS RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY
5 TO 6.5 YEARS. FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE
HAPPENS ONLY ONCE IN EVERY 15 TO 25 YEARS. GIVEN THESE
FACTORS...AND CONSIDERING THE ABOVE...KEPT ONGOING SNOWFALL
AMOUNTS CLOSE TO THE ONGOING/INHERITED AMOUNTS...WITH THE LATEST
THINKING THAT TOTAL SNOWFALL AMOUNTS FROM THIS STORM SHOULD RANGE
FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL IMPACTS WILL BE MOUNTING
SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING AND DRIFTING SNOW.
RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING GIVEN THE NEW AND
FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT SURFACE PRESSURE
GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD END FROM WEST
TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED ROADS WILL
LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING WELL BELOW
ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETEORATION INTO LONG LIVED LIFR EVENT DURING
DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO MULTI
MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY. LATER
FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL BEGIN TO
BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311722
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1222 PM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY
AFTERNOON AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND
MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE
FINE TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH
DIMINISHED AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF
WARM WET BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C
WET BULB PER KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A
PARTIAL MELT OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS
OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW
OVERSPREAD THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH
IMPACT SNOW EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE
LONG TERM SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT
FROM 00Z THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER
STORM WATCH IN EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR
THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH
SOME MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS
THIS MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE
NEXT FEW HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE
NORTHERN GREAT LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE
FAR NORTH...BUT MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST
THROUGH EARLY AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS
IS EXPECTED LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR
UPCOMING SNOW EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES.
HIGH TEMPERATURES THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER
THAN YESTERDAY INTO THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST
IMPACTS WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED
IN LONG TERM SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING
APPROACHES THE REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS
COMING TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING
SNOW. MOISTURE LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER
LEVELS WILL ARRIVE IN TANDEM AS THE NORTHERN STREAM SYSTEM AND
THE SOUTHERN STREAM PHASE. PRECIPITATION EFFICIENCY WITH THIS
SETUP SHOULD BE VERY GOOD. FOR THIS EVENT...FAVORED A GFS
SOLUTION. THE GFS HAS BEEN TRENDING TOWARD A SLOWER AND MORE
NORTHERN TRACK AND A RELATIVELY LONG DURATION EVENT. ALSO...THIS
GFS SEEMS TO BE HANDLING ALL OF THE SIGNIFICANT PARAMETERS FOR
THIS WINTER STORM REASONABLY WELL. THE 290K GARCIA/MIXING RATIO
METHOD RENDERS 8 TO 12 INCHES OF SNOW...WITH LESSER AMOUNTS OVER
FAR SOUTHERN LOWER MICHIGAN. STILL SOME UNCERTAINTY OVER THIS FAR
NORTHERN PORTION OF THE AREA GIVEN LOWER MIXING RATIOS AND A
GREATER CHANCE FOR DRY AIR ENTRAINMENT WITH LOW LEVEL/DRIER
NORTHEAST FLOW DURING THE SECOND HALF OF THE EVENT. THEREFORE...
AFTER COORDINATION WITH SURROUNDING OFFICES... KEPT LOWER
MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO THE NEXT
SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF
AND NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS
NORTHERN INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH
FT WAYNE AND LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8
INCHES OR MORE IS RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY
5 TO 6.5 YEARS. FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE
HAPPENS ONLY ONCE IN EVERY 15 TO 25 YEARS. GIVEN THESE
FACTORS...AND CONSIDERING THE ABOVE...KEPT ONGOING SNOWFALL
AMOUNTS CLOSE TO THE ONGOING/INHERITED AMOUNTS...WITH THE LATEST
THINKING THAT TOTAL SNOWFALL AMOUNTS FROM THIS STORM SHOULD RANGE
FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL IMPACTS WILL BE MOUNTING
SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING AND DRIFTING SNOW.
RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING GIVEN THE NEW AND
FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT SURFACE PRESSURE
GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD END FROM WEST
TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED ROADS WILL
LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING WELL BELOW
ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1217 PM EST SAT JAN 31 2015

HIGH CONFIDENCE FOR DETEORATION INTO LONG LIVED LIFR EVENT DURING
DAYTIME HOURS SUNDAY. INCREASED CONFIDENCE WITH RESPECT TO MULTI
MODEL CONSENSUS FOR ALL SNOW EVENT/HEAVY AT TIMES SUNDAY. LATER
FORECAST ITERATIONS WILL INCLUDE BLSN AS SFC WINDS WILL BEGIN TO
BACK AND RAMP CONSIDERABLY LT SUNDAY AFTN INTO NIGHT.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MURPHY


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIND 311720
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1220 PM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 7 PM EST THIS EVENING THROUGH MONDAY
MORNING FOR INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 311720
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1220 PM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311800Z TAF ISSUANCE/...

ISSUED AT 1216 PM EST SAT JAN 31 2015

THE MAIN PROBLEM DURING THIS TAF CYCLE WILL BE PRECIPITATION
TYPE...ESPECIALLY ACROSS IND/HUF/BMG.

EXPECT VFR CONDITIONS TO CONTINUE THROUGH THE DAY TODAY WITH
MID/HIGH CLOUDS OVERSPREADING THE TAF SITES EARLY THIS AFTERNOON.
EXPECT TO SEE A SCATTERED DECK AT 2500 TO 3000 FEET ARRIVE LATE
THIS AFTERNOON AS THE SURFACE LOW PRESSURE BEGINS TO TAKE SHAPE
OVER THE CENTRAL PLAINS. AROUND 00Z SUNDAY...PRECIPITATION IS
EXPECTED TO PUSH INTO THE TAF SITES GENERALLY AS A MIX OF SNOW AND
RAIN. HOWEVER...WOULD NOT BE SURPRISED IF PRECIP STARTS AS RAIN
THEN TRANSITIONS TO THE MIX AND THEN TO SNOW LATE TONIGHT. SHORTLY
AFTER 00Z...CEILINGS ARE EXPECTED TO DROP INTO THE MVFR
CATEGORY...AROUND 1500 TO 2000 FEET. EXPECT CEILINGS TO STEADILY
DROP TO IFR SUNDAY AS THE HEAVIEST OF THE PRECIPITATION STARTS TO
FALL AROUND 14 TO 15Z FOR ALL SITES EXCEPT LAF...WHICH WILL OCCUR
A FEW HOURS EARLIER. BUFKIT SOUNDINGS INTRODUCE SOME WARM AIR INTO
THE TEMPERATURE PROFILE UP TO ABOUT 5000 FEET ACROSS THE
IND/HUF/BMG SITES AS THE LOW APPROACHES AND PUSHES EAST INTO
SOUTHERN INDIANA FROM THE WEST. THIS MAY BE ENOUGH TO CHANGE
PRECIPITATION BACK TO A MIX AT IND AND BACK TO RAIN AT HUF/BMG BY
18Z. DUE TO THE RECENT VARIABILITY IN THE TRACK OF THE
LOW...CONFIDENCE IS NOT HIGH ON PRECIPITATION TYPE AT IND/HUF/BMG
FOR SUNDAY AFTERNOON.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 7 PM EST THIS EVENING THROUGH MONDAY
MORNING FOR INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 311449
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
949 AM EST SAT JAN 31 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 7 PM EST THIS EVENING THROUGH MONDAY
MORNING FOR INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 311449
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
949 AM EST SAT JAN 31 2015

.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 943 AM EST SAT JAN 31 2015

0935Z UPDATE...MORNING UPDATE FOCUS WAS ON FOR THE REST OF TODAY
WHICH APPEARS TO BE IN GOOD SHAPE. ONLY NEEDED TO MAKE SOME MINOR
MODIFICATIONS BASED ON LATEST TEMP/DEW POINT/SKY TRENDS.

THE TENTATIVE PLAN WITH REGARD TO WINTER WEATHER HEADLINES IS TO
WAIT FOR THE REST OF THE GUIDANCE TO COME IN THIS
MORNING...EVALUATE AND HOPEFULLY MAKE A DECISION(S) BY EARLY THIS
AFTERNOON.

PREVIOUS DISCUSSION FOLLOWS...

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /THIS EVENING THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM 7 PM EST THIS EVENING THROUGH MONDAY
MORNING FOR INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...SMF/TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 311412
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
912 AM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 311412
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
912 AM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 311412
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
912 AM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 311412
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
912 AM EST SAT JAN 31 2015

.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES INTO
THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT NORTHERLY
SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP TO 9 TO 12
INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF COUNTIES WILL MOST
LIKELY HAVE TO BE ADDED TO THE WARNING WITH NEXT FORECAST ISSUANCE.
MEDIUM CONFIDENCE FORECAST ACROSS THE CENTRAL TIER OF
COUNTIES...WHICH WILL BE RIGHT ALONG SHARP PRECIPITATION GRADIENT.
ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE THE BEST CUT-OFF
POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3 TO 6 INCHES OF
TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE RECEIVING 6 TO 9
INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL CHANGE SINCE MOST
UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311500Z TAF ISSUANCE/...
ISSUED AT 912 AM EST SAT JAN 31 2015

UPDATED CURRENT CONDITIONS ONLY. PREVIOUS DISCUSSION FOLLOWS...

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH/CP

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIWX 311326
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
826 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE 30S...MUCH
COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE FINE
TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH DIMINISHED
AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF WARM WET
BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C WET BULB PER
KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A PARTIAL MELT
OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311326
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
826 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE 30S...MUCH
COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE FINE
TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH DIMINISHED
AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF WARM WET
BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C WET BULB PER
KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A PARTIAL MELT
OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311326
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
826 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE 30S...MUCH
COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE FINE
TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH DIMINISHED
AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF WARM WET
BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C WET BULB PER
KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A PARTIAL MELT
OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311326
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
826 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE 30S...MUCH
COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.UPDATE...
ISSUED AT 825 AM EST SAT JAN 31 2015

DISCONTENT WITH MICHIGAN COUNTIES UNDER WATCH ESPECIALLY GIVEN 03
UTC SREF/06 UTC NAM ALONG WITH WPC CONTINUING TO PEG NRN THIRD
WITH HIEST SNOW SWATH. DEGREE OF ISENT MOISTURE FLUX
CONVERGENCE/ADVECTION INTO SRN LWR MI TO EASILY OVERWHELM/SHUNT
NWD ANY DRY AIR ENTRAINMENT ISSUES. REVERT TO BROAD 6 TO 12 INCH
ACCUMS AND AWAIT 12 UTC MODEL SUITE/09 UTC SREF OUTPUT BEFORE FINE
TUNING WITH APPLICATION OF GREATER MESOSCALE DETAIL/WARNING
SEGMENTATION. ACTUALLY RIGHT NOW AM MORE CONCERNED WITH DIMINISHED
AMOUNTS FAR SWRN/SRN IN COUNTIES OWING TO MAGNITUDE OF WARM WET
BULB WEDGE EXTRUDED NWD THROUGH INDIANA. 1KFT PLUS 1C WET BULB PER
KGUS 06 UTC NAM PROFILE...WOULD SUGGEST AT LEAST A PARTIAL MELT
OVERNIGHT...LENDING TO LOWER SLR FOR FIRST 6-9 HOURS OF EVENT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 311148
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
648 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 311148
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
648 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 311148
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
648 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIWX 311148
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
648 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 641 AM EST SAT JAN 31 2015

VFR CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE DAY...WITH THE
POSSIBILITY OF SOME VFR LOW CLOUDS MOVING INTO NORTHERN INDIANA
LATER THIS MORNING IN ASSOCIATION WITH UPPER WAVE TRACKING ACROSS
THE GREAT LAKES. CONDITIONS TO DETERIORATE TONIGHT AS LEAD SHORT
WAVE AND ISENTROPIC LIFT INCREASE WITH LIGHT SNOW OVERSPREADING
THE TERMINALS. HAVE CONTINUED TREND FROM 06Z TAFS WITH TRANSITION
TO IFR VSBYS BY LATE EVENING...WITH INTENSITY OF SNOW INCREASING
TOWARD DAYBREAK SUNDAY. FURTHER DETERIORATION IS EXPECTED JUST
AFTER THIS FORECAST VALID PERIOD AS THE PRIMARY UPPER LEVEL SYSTEM
APPROACHES THE REGION WITH SIGNIFICANT SNOW ACCUMULATIONS FOR
SUNDAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 311113 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EST SAT JAN 31 2015

.UPDATE...
AVIATION SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311200Z TAF ISSUANCE/...
ISSUED AT 612 AM EST SAT JAN 31 2015

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 311113 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EST SAT JAN 31 2015

.UPDATE...
AVIATION SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311200Z TAF ISSUANCE/...
ISSUED AT 612 AM EST SAT JAN 31 2015

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 311113 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EST SAT JAN 31 2015

.UPDATE...
AVIATION SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311200Z TAF ISSUANCE/...
ISSUED AT 612 AM EST SAT JAN 31 2015

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 311113 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EST SAT JAN 31 2015

.UPDATE...
AVIATION SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAR AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 311200Z TAF ISSUANCE/...
ISSUED AT 612 AM EST SAT JAN 31 2015

VFR TODAY AND MVFR OR IFR FLIGHT CONDITIONS TONIGHT AND SUNDAY.

HIGH PRESSURE OVER THE EASTERN U.S. WILL MOVE ON TO THE EAST AS LOW
PRESSURE OVER THE ROCKIES MOVE INTO THE SOUTHERN PLAINS TONIGHT AND
INTO SOUTHERN INDIANA LATE SUNDAY.

FOR TODAY...EXPECT INCREASING MID/HIGH CLOUDS WITH RAIN/SNOW MOVING
INTO WESTERN SECTIONS LATE THIS AFTERNOON AND ELSEWHERE THIS
EVENING.  PRECIPITATION MAY START OUT AS RAIN AND THEN BECOMING
MIXED WITH OR CHANGING TO ALL SNOW LATER THIS EVENING.  SOME MODELS
INDICATE SOME IMPROVEMENT OVER SOUTHERN SECTIONS LATER TONIGHT WHILE
NORTHERN AREAS MAY BECOME MOSTLY IFR.

SOUTHWEST WINDS UP TO 8 TO 10 KNOTS TODAY WILL BECOME LIGHT THIS
EVENING AND EAST UP TO 5 KNOTS BY SUNDAY MORNING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIWX 311004
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
504 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 311004
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
504 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 311004
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
504 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 311004
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
504 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 501 AM EST SAT JAN 31 2015

A WINTER STORM WILL IMPACT THE REGION BEGINNING TONIGHT AND
CONTINUING INTO SUNDAY NIGHT. THE HEAVIEST SNOW WITH THIS SYSTEM
IS EXPECTED SUNDAY MORNING THROUGH EARLY SUNDAY EVENING...WITH
BLOWING AND DRIFTING SNOW ALSO BECOMING A CONCERN SUNDAY AFTERNOON
AND EVENING. AFTER MILDER CONDITIONS TODAY INTO THE
30S...MUCH COLDER TEMPERATURES ARE IN STORE FOR SUNDAY NIGHT AND MONDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 501 AM EST SAT JAN 31 2015

FORECAST CONCERNS FOR THE SHORT TERM WILL CENTER ON SNOW OVERSPREAD
THE AREA TONIGHT WHICH WILL LEAD INTO POTENTIALLY HIGH IMPACT SNOW
EVENT FOR THE AREA INTO SUNDAY NIGHT COVERED IN THE LONG TERM
SECTION BELOW. A WINTER STORM WARNING WILL BE IN EFFECT FROM 00Z
THIS EVENING THROUGH 09Z MONDAY MORNING WITH A WINTER STORM WATCH IN
EFFECT FOR SOUTHERN LOWER MICHIGAN COUNTIES FOR THE SAME TIMES.

QUIET WEATHER EXPECTED TO CONTINUE THROUGH MOST OF THE DAY WITH SOME
MID LEVEL WAA INDUCED CLOUDINESS ACROSS NORTHERN ILLINOIS THIS
MORNING EXPECTED TO SHIFT ACROSS NORTHERN INDIANA OVER THE NEXT FEW
HOURS. AN UPPER LEVEL SHORT WAVE TRACKING ACROSS THE NORTHERN GREAT
LAKES MAY ALLOW SOME LOW CLOUDS TO PUSH ACROSS THE FAR NORTH...BUT
MOST LOCATIONS SHOULD BE PARTLY CLOUDY AT LEAST THROUGH EARLY
AFTERNOON. AN INCREASE IN MID AND HIGH LEVEL CLOUDS IS EXPECTED
LATER THIS AFTERNOON AS PRIMARY SHORT OF INTEREST FOR UPCOMING SNOW
EVENT BEGINS TO DIG ACROSS THE CENTRAL ROCKIES. HIGH TEMPERATURES
THIS AFTERNOON SHOULD BE 3 TO 6 DEGREES WARMER THAN YESTERDAY INTO
THE LOWER AND MID 30S.

FOR TONIGHT A SHEARED UPPER LEVEL SHORT WAVE WILL LIFT INTO THE
SOUTHERN GREAT LAKES REGION DOWNSTREAM OF PRIMARY VORT MAX. BROAD
SYNOPTIC SUPPORT FOR UVM WILL ALSO INCREASE AS LOCAL AREA BECOMES
POSITIONED IN FAVORABLE RIGHT ENTRANCE OF UPPER JET. ISENTROPIC
ASCENT PER 290K SFC ALSO TO SIGNIFICANTLY RAMP UP TOWARD DAYBREAK
SUNDAY. OVERALL EXPECTING LIGHT SNOWFALL AMOUNTS IN THE 1 TO 3 INCH
RANGE FOR TONIGHT...WHICH WILL LEAD INTO PERIOD OF GREATEST IMPACTS
WITH THIS WINTER STORM ON SUNDAY/SUNDAY NIGHT DISCUSSED IN LONG TERM
SECTION BELOW AS STRONGER MID/UPPER LEVEL FORCING APPROACHES THE
REGION.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 501 AM EST SAT JAN 31 2015

HEAVY SNOW IS EXPECTED EARLY SUNDAY...CONTINUING THROUGH SUNDAY
EVENING BEFORE ENDING EARLY MONDAY. SEVERAL FAVORABLE FACTORS COMING
TOGETHER FOR A WINTER STORM WITH HEAVY SNOW AND BLOWING SNOW. MOISTURE
LADEN SUBTROPICAL MOISTURE IN THE MID TO UPPER LEVELS WILL ARRIVE IN
TANDEM AS THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM PHASE.
PRECIPITATION EFFICIENCY WITH THIS SETUP SHOULD BE VERY GOOD. FOR
THIS EVENT...FAVORED A GFS SOLUTION. THE GFS HAS BEEN TRENDING
TOWARD A SLOWER AND MORE NORTHERN TRACK AND A RELATIVELY LONG
DURATION EVENT. ALSO...THIS GFS SEEMS TO BE HANDLING ALL OF THE
SIGNIFICANT PARAMETERS FOR THIS WINTER STORM REASONABLY WELL. THE
290K GARCIA/MIXING RATIO METHOD RENDERS 8 TO 12 INCHES OF
SNOW...WITH LESSER AMOUNTS OVER FAR SOUTHERN LOWER MICHIGAN. STILL
SOME UNCERTAINTY OVER THIS FAR NORTHERN PORTION OF THE AREA GIVEN
LOWER MIXING RATIOS AND A GREATER CHANCE FOR DRY AIR ENTRAINMENT
WITH LOW LEVEL/DRIER NORTHEAST FLOW DURING THE SECOND HALF OF THE
EVENT. THEREFORE... AFTER COORDINATION WITH SURROUNDING OFFICES...
KEPT LOWER MICHIGAN IN A WINTER STORM WATCH FOR NOW AND DEFERRED TO
THE NEXT SHIFT THE OPTION TO UPDATE. WAS HESITANT TO RAISE HIGH END
SNOWFALL AMOUNTS IN LIGHT OF CLIMATE DATA...ALTHOUGH GFS...ECMWF AND
NAM ALL SUPPORT SNOWFALL TOTALS OF 12 TO 15 INCHES ACROSS NORTHERN
INDIANA AND NORTHWEST OHIO. CLIMATE PERCENTAGES AT BOTH FT WAYNE AND
LAFAYETTE INDICATE A TWO DAY SNOWFALL TOTAL OF 8 INCHES OR MORE IS
RARE...IT ONLY HAPPENS ON AVERAGE OF ONCE EVERY 5 TO 6.5 YEARS.
FURTHERMORE...A SNOWFALL OF 12 INCHES OR MORE HAPPENS ONLY ONCE IN
EVERY 15 TO 25 YEARS. GIVEN THESE FACTORS...AND CONSIDERING THE
ABOVE...KEPT ONGOING SNOWFALL AMOUNTS CLOSE TO THE ONGOING/INHERITED
AMOUNTS...WITH THE LATEST THINKING THAT TOTAL SNOWFALL AMOUNTS FROM
THIS STORM SHOULD RANGE FROM 7 TO 11 INCHES. SIGNIFICANT TRAVEL
IMPACTS WILL BE MOUNTING SUNDAY NIGHT AS WINDS INCREASE WITH BLOWING
AND DRIFTING SNOW. RAISED WIND SPEEDS CONSIDERABLY SUNDAY EVENING
GIVEN THE NEW AND FARTHER NORTH AND DEEPER GFS LOW WITH A TIGHT
SURFACE PRESSURE GRADIENT OVER THE AREA. OTHERWISE...SNOWFALL SHOULD
END FROM WEST TO EAST LATE SUNDAY NIGHT. SNOW DRIFTS ON UNPLOWED
ROADS WILL LIKELY MAKE SOME ROADS IMPASSIBLE. WIND CHILLS DROPPING
WELL BELOW ZERO EARLY MONDAY MORNING ARE EXPECTED.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 4
     AM EST /3 AM CST/ MONDAY FOR INZ003>009-012>018-020-022>027-
     032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH LATE SUNDAY NIGHT
     FOR MIZ077>081.

OH...WINTER STORM WARNING FROM 7 PM THIS EVENING TO 4 AM EST MONDAY
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MARSILI
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIND 311000 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
500 AM EST SAT JAN 31 2015

.UPDATE...
THE SHORT TERM SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAT AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 311000 AAA
AFDIND

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
500 AM EST SAT JAN 31 2015

.UPDATE...
THE SHORT TERM SECTION HAS BEEN CORRECTED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.

&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 457 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

.CORRECTION...
AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND HOWARD COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAT AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 310936
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
436 AM EST SAT JAN 31 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 352 AM EST SAT JAN 31 2015

SIGNIFICANT STORM SYSTEM IS STILL EXPECTED TO IMPACT CENTRAL
INDIANA FROM SATURDAY NIGHT THROUGH SUNDAY NIGHT. AS THE SYSTEM
PUSHES AWAY ON MONDAY...FRIGID TEMPS WILL FILTER INTO THE REGION.
AFTER A RETURN TO NORMAL TEMPS AROUND MID-WEEK...THE BITTER COLD
TEMPS WILL RETURN AT THE END OF THE WEEK IN THE WAKE OF A COLD
FRONT. THIS COLD FRONT WILL ALSO BE RESPONSIBLE FOR WINTER
PRECIPITATION FROM TUESDAY NIGHT THROUGH WEDNESDAY NIGHT.

&&

.NEAR TERM /THIS MORNING/...

ISSUED AT 352 AM EST SAT JAN 31 2015

CURRENT IR SAT SHOWS SOME INCREASING MID AND HIGH CLOUDS ACROSS
THE SOUTHWEST COUNTIES WITH HIGH PRESSURE CENTERED OVER THE OHIO
VALLEY. THE MAIN TREND FOR THIS MORNING AND TODAY WILL BE THE
INCREASING MID AND HIGH CLOUDS AS STORM SYSTEM APPROACHES FROM THE
WEST/SOUTHWEST. AS SOUTHWEST FLOW STRENGTHENS SLIGHTLY THIS
AFTERNOON...TEMPS WILL WARM INTO THE UPPER 30S/LOW 40S. TRENDED
TOWARD THE SLIGHTLY WARMER GFS FOR TODAY/S HIGHS...FEEL WARM
ADVECTION MAY BE UNDERDONE SLIGHTLY BY MOST MODELS.


&&

.SHORT TERM /TODAY THROUGH MONDAY NIGHT/...

ISSUED AT 352 AM EST SAT JAN 31 2015

THE MAIN FOCUS OF THE SHORT TERM PERIOD CONTINUES TO BE THE STORM
SYSTEM AND SNOWFALL AMOUNTS THIS WEEKEND.

TIMING...LATEST MODEL RUNS OF NAM/GFS/EURO HAVE ALL TAKEN A SLIGHTLY
MORE NORTHERLY ROUTE BUT REMAIN RATHER CONSISTENT IN THE TRACK
AND TIMING OF SYSTEM...THE EURO BEING JUST SLIGHTLY SLOWER THAN
THE NAM AND GFS. LIGHT RAIN SHOWERS SHOULD START ENTERING THE
WESTERN COUNTIES AROUND SUN 00Z...INCREASING SLIGHTLY AROUND SUN
03Z. ISENTROPIC LIFT/BEST DYNAMICS REALLY STRENGTHEN AROUND SUN
06Z AND REMAIN STRONG THROUGH MON 00Z.

PRECIP TYPE...THERE HAVE BEEN MODIFICATIONS TO PRECIP TYPE AND
AMOUNTS WITH LATEST MODEL RUNS. MAIN CONCERN IS THAT WARM
ADVECTION MAY BE UNDERDONE OVER THE SOUTHERN COUNTIES TODAY AND
TOMORROW. DECENT SOUTHWEST FLOW IS GOING TO ALLOW TEMPERATURES TO
CLIMB INTO THE UPPER 30S/LOW 40S OVER MOST OF THE FORECAST AREA
TODAY. COLDER AIR WILL HAVE TIME TO FILTER INTO CENTRAL TIER OF
COUNTIES BY THIS EVENING...BUT DO NOT THINK THE SOUTHERNMOST
COUNTIES WILL BE ABLE TO RECOVER FROM THE WARM TEMPERATURES OF
TODAY AND TOMORROW. BUFKIT SOUNDINGS INDICATE SNOW ACROSS
LAFAYETTE AND INDIANAPOLIS BY EARLY THIS EVENING...BUT NOT
A CHANGE TO SNOW AT TERRE HAUTE UNTIL AFTER SUN 04Z...AND
SOUTHERN COUNTIES NEVER CHANGE OVER FROM RAIN /EXCEPT BRIEFLY
LATE TONIGHT OVER SOUTHEAST COUNTIES/. AS A RESULT...REMOVED
VIGO...CLAY...AND OWEN COUNTIES FROM THE WINTER STORM WATCH.

AMOUNTS...HIGH CONFIDENCE IN LARGE AMOUNTS OF SNOW OVER THE
NORTHERNMOST COUNTIES...SO INSERTED CARROLL AND TIPTON COUNTIES
INTO THE WINTER STORM WARNING AT THIS TIME. DUE TO THE SLIGHT
NORTHERLY SHIFT IN THE STORM TRACK...THESE COUNTIES COULD SEE UP
TO 9 TO 12 INCHES OF SNOW ACCUMULATION...AND ANOTHER TIER OF
COUNTIES WILL MOST LIKELY HAVE TO BE ADDED TO THE WARNING WITH
NEXT FORECAST ISSUANCE. MEDIUM CONFIDENCE FORECAST ACROSS THE
CENTRAL TIER OF COUNTIES...WHICH WILL BE RIGHT ALONG SHARP
PRECIPITATION GRADIENT. ONCE AGAIN...THE I-70 CORRIDOR SEEMS TO BE
THE BEST CUT-OFF POINT...WITH THE SOUTHERN SIDE RECEIVING AROUND 3
TO 6 INCHES OF TOTAL SNOWFALL ACCUMULATION...AND THE NORTHERN SIDE
RECEIVING 6 TO 9 INCHES OF SNOW. AGAIN...THESE AMOUNTS COULD STILL
CHANGE SINCE MOST UNCERTAINTY LIES IN THIS PARTICULAT AREA.

SYSTEM WILL WIND DOWN BETWEEN MON 00-06Z WITH MOST OF PRECIP OUT
OF THE AREA BEFORE MONDAY MORNING COMMUTE. THERE WILL BE THE
POSSIBILITY FOR SOME LAKE EFFECT SNOW SHOWERS ACROSS THE FAR
NORTH/NORTHWESTERN COUNTIES ON MONDAY MORNING...BUT NO ADDITIONAL
ACCUMULATIONS ARE EXPECTED FROM THAT. MONDAY NIGHT WILL BE DRY WITH
BITTER COLD TEMPERATURES FALLING INTO THE SINGLE DIGITS ACROSS THE
NORTH...TO TEENS ACROSS THE SOUTH AS CLOUDS SCATTER A BIT.
DAYTIME HIGHS WILL NOT BE MUCH BETTER ON MONDAY EITHER...WITH
READINGS ONLY IN THE TEENS TO LOW 20S.


&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...TDUD
NEAR TERM...TDUD
SHORT TERM...TDUD
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 310843
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
340 AM EST FRI JAN 30 2015

.UPDATE...
LONG TERM AND AVIATION SECTION HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&


.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 310843
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
340 AM EST FRI JAN 30 2015

.UPDATE...
LONG TERM AND AVIATION SECTION HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&


.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 310843
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
340 AM EST FRI JAN 30 2015

.UPDATE...
LONG TERM AND AVIATION SECTION HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&


.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIND 310843
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
340 AM EST FRI JAN 30 2015

.UPDATE...
LONG TERM AND AVIATION SECTION HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&


.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 340 AM EST SAT JAN 31 2015

ALL MODELS CONTINUE A NORTHWEST FAST FLOW ALOFT THROUGH THE LONG
TERM. TEMPERATURES WILL AVERAGE BELOW NORMAL...BUT SIGNIFICANT DAY
TO DAY CHANGES WILL OCCUR AS A COUPLE OF SYSTEMS MOVE RAPIDLY ACROSS
OUR REGION.

MODELS DEVELOP A SOUTHWEST FLOW TUESDAY AS HIGH PRESSURE MOVES OFF
TO THE EAST.  THIS WILL ALLOW TEMPERATURES TO WARM BACK UP INTO THE
30S TUESDAY AFTER A COLD START TUESDAY MORNING.  THERE WILL BE
INCREASING CLOUDS TUESDAY NIGHT WITH A SLIGHT CHANCE OF SNOW LATE
TUESDAY NIGHT IN THE NORTH AS A COLD FRONT APPROACHES.  THIS COLD
FRONT WILL MOVE SOUTH ACROSS OUR REGION WEDNESDAY PRODUCING A SLIGHT
CHANCE OF SNOW OVER NORTHERN SECTIONS AND A SLIGHT CHANCE OF MIXED
PRECIPITATION ELSEWHERE...EXCEPT THE FAR SOUTH WILL REMAINS DRY
UNTIL WEDNESDAY EVENING.

GFS AND GEMNH MODELS INDICATE SLIGHT CHANCE POPS CENTRAL AND SOUTH
WEDNESDAY EVENING...WHILE THE EURO IS DRY.  MEANWHILE ALL MODELS
INDICATE DRY WEATHER REST OF THE LONG TERM AS AN ARCTIC HIGH
PRESSURE SYSTEM BUILDS EAST INTO THE SOUTHERN GREAT LAKES BY
THURSDAY NIGHT.

MODELS HAVE TRENDED A LITTLE WARMER TUESDAY INTO WEDNESDAY MORNING.
HOWEVER IT MAY BE A BIT TOO WARM NORTH WITH SNOW COVER. CUT
TEMPERATURES A LITTLE LATE WEDNESDAY ON...AS ARCTIC AIR MOVES BACK
INTO OUR REGION. SUB ZERO TEMPERATURES ARE POSSIBLE NORTH BY FRIDAY
MORNING.

&&

.AVIATION /DISCUSSION FOR THE 310900Z KIND TAF UPDATE/...
ISSUED AT 340 AM EST SAT JAN 31 2015

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES ARE NEEDED AT THIS TIME.

PREVIOUS AVIATION DISCUSSION FOLLOWS...
NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM THIS EVENING THROUGH MONDAY MORNING FOR
INZ028>030-035>049-054>057.

WINTER STORM WARNING FROM 7 PM THIS EVENING TO 7 AM EST MONDAY
FOR INZ021-031.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...JH
AVIATION...JAS/JH

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS







000
FXUS63 KIWX 310615
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     MIZ077>081.

OH...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 310615
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     MIZ077>081.

OH...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 310615
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     MIZ077>081.

OH...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 310615
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
115 AM EST SAT JAN 31 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1239 AM EST SAT JAN 31 2015

LIGHT SOUTHWEST FLOW THROUGH THIS AFTERNOON AS LOW LEVEL RIDGE
AXIS CONTINUES TO DROP SOUTHEAST ACROSS THE MID ATLANTIC STATES.
SOME INCREASE IN MID LEVEL WAA CLOUDS EXPECTED THIS MORNING...AND
SCT-BKN HIGH CLOUDINESS...BUT MVFR CIGS SHOULD HOLD OFF UNTIL
TONIGHT. LEAD UPPER VORT MAX ASSOCIATED WITH NEXT SIGNIFICANT
SYSTEM TO IMPACT THE AREA COMBINED WITH ISENTROPIC UPGLIDE WILL
ALLOW SNOW TO OVERSPREAD TERMINALS IN THE EVENING AND HAVE
INTRODUCED IFR VSBYS TOWARD THE END OF THIS PERIOD. SNOWFALL
INTENSITY/CIGS/VSBYS TO DETERIORATE MORE SIGNIFICANTLY AFTER THIS
FORECAST VALID PERIOD AND ESPECIALLY AFTER 12Z SUNDAY AS PRIMARY
UPPER LEVEL TROUGH APPROACHES FROM THE WEST.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     MIZ077>081.

OH...WINTER STORM WATCH FROM THIS EVENING THROUGH SUNDAY EVENING FOR
     OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...MARSILI


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIND 310403
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1103 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310600Z TAFS/...
ISSUED AT 1103 PM EST FRI JAN 30 2015

NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 310403
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1103 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310600Z TAFS/...
ISSUED AT 1103 PM EST FRI JAN 30 2015

NO SIGNIFICANT CLOUD COVER AND UNRESTRICTED VISIBILITY EXPECTED AT
THE TAF SITES THROUGH 311800Z.

LIGHT SURFACE WINDS OVERNIGHT EXPECTED TO BECOME 200-220 DEGREES AT
8-12 KTS BY LATE MORNING SATURDAY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 310256
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
956 PM EST FRI JAN 30 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 310256
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
956 PM EST FRI JAN 30 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 310256
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
956 PM EST FRI JAN 30 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 310256
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
956 PM EST FRI JAN 30 2015

.UPDATE...

THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY
MORNING. IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL
PREVAIL ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL
PRECIPITATION CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND
WEDNESDAY AS A COLD FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 956 PM EST FRI JAN 30 2015

GOING FORECAST IN EXCELLENT SHAPE AND NO SIGNIFICANT CHANGES
REQUIRED. SHOULD REMAIN CLEAR OR MOSTLY CLEAR MOST OF THE NIGHT WITH
PERHAPS A FEW HIGH CLOUDS STREAMING ACROSS PORTIONS OF THE AREA
LATE. PREVIOUS DISCUSSION FOLLOWS.

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...
ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST
AREA...EXCEPT FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES
TO A FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME
CONSISTENCY WITH REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE
OHIO VALLEY AND THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN
ARRIVES SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY
NIGHT INTO EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE
TEMPERATURES AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS
NOW POSSIBLE ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY
AFTERNOON. THIS WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO
REFLECT SNOW LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY
AFTERNOON/EARLY EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS
THIS AREA CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE
FROM THE SNOW TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP
SNOWFALL GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS
IN THE HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...

WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF/NIELD
SHORT TERM...SMF
LONG TERM...PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS






000
FXUS63 KIND 310220
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
918 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS














000
FXUS63 KIND 310220
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
918 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310300Z KIND TAF UPDATE/...
ISSUED AT 918 PM EST FRI JAN 30 2015

NO SIGNIFICANT CHANGES MADE TO THE FORECAST AT THIS TIME. PREVIOUS
DISCUSSION FOLLOWS.

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS













000
FXUS63 KIWX 302334
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
634 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 624 PM EST FRI JAN 30 2015

HIGH PRESSURE RIDGE ALONG THE INDIANA/ILLINOIS BORDER WILL MOVE EAST
ACROSS NRN INDIANA THIS EVE CAUSING LIGHT NW FLOW TO BACK SW. PLUME
OF LAKE EFFECT MVFR STRATO CU MOVG INTO FWA ATTM SHOULD CLEAR OUT BY
LATE EVE. SW FLOW WILL CONTINUE SATURDAY AND STRENGTHEN A BIT AS
HIGH MOVES EAST AND A WK CDFNT APPROACHES FROM THE NW. VFR
CONDITIONS EXPECTED TO CONTINUE LATE TONIGHT AND SATURDAY WITH JUST
SOME INCREASING HIGH CLOUDINESS MOVG IN FROM THE W-SW DURING THE DAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA






000
FXUS63 KIWX 302334
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
634 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

HIGH PRESSURE WILL MOVE SOUTHEAST ACROSS THE OHIO VALLEY TONIGHT
AND SATURDAY PROVIDING FAIR WEATHER ACROSS OUR AREA. LOWS TONIGHT
WILL RANGE FROM 11 TO 17... WITH HIGHS SATURDAY IN THE LOWER TO
MIDDLE 30S. LOW PRESSURE IS EXPECTED MOVE FROM THE THE PLAINS
SATURDAY NIGHT TO THE UPPER OHIO VALLEY SUNDAY NIGHT. THIS SYSTEM
WILL CAUSE SNOW... POSSIBLY HEAVY... IN OUR AREA SATURDAY NIGHT
THROUGH SUNDAY NIGHT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 624 PM EST FRI JAN 30 2015

HIGH PRESSURE RIDGE ALONG THE INDIANA/ILLINOIS BORDER WILL MOVE EAST
ACROSS NRN INDIANA THIS EVE CAUSING LIGHT NW FLOW TO BACK SW. PLUME
OF LAKE EFFECT MVFR STRATO CU MOVG INTO FWA ATTM SHOULD CLEAR OUT BY
LATE EVE. SW FLOW WILL CONTINUE SATURDAY AND STRENGTHEN A BIT AS
HIGH MOVES EAST AND A WK CDFNT APPROACHES FROM THE NW. VFR
CONDITIONS EXPECTED TO CONTINUE LATE TONIGHT AND SATURDAY WITH JUST
SOME INCREASING HIGH CLOUDINESS MOVG IN FROM THE W-SW DURING THE DAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...JT


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 302239
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
538 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310000Z TAFS/...
ISSUED AT 538 PM EST FRI JAN 30 2015

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS











000
FXUS63 KIND 302239
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
538 PM EST FRI JAN 30 2015

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 310000Z TAFS/...
ISSUED AT 538 PM EST FRI JAN 30 2015

LINGERING CLOUD COVER BASED AROUND 035 IN THE PROCESS OF DISSIPATING
AND SHOULD BE GONE BY ISSUANCE TIME.

OTHERWISE...UNLIMITED CEILING...UNRESTRICTED VISIBILITY...SURFACE
WINDS AT OR BELOW 5 KTS EXPECTED AT THE TAF SITES TONIGHT.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...JAS

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS










000
FXUS63 KIND 302153
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
453 PM EST FRI JAN 30 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 301800Z TAF CYCLE/...

ISSUED AT 1257 PM EST FRI JAN 30 2015

EXPECT VFR CONDITIONS TO CONTINUE...BUT JUST BARELY...AT ALL TAF
SITES DURING THIS CYCLE. CURRENT DECK OF CLOUDS OVER LAF/IND ARE
JUST SLIGHTLY IN THE VFR CATEGORY WITH BKN/OVR CEILINGS IN THE
3100 TO 3300 FOOT RANGE. THERE ARE A COUPLE OBS UPSTREAM OF THESE
TWO SITES THAT ARE DEPICTING CEILINGS AT OR BELOW 3000 FEET...HOWEVER
THOSE SITES ARE MORE ENTRENCHED WITHIN THE CURRENT CLOUD MASS.
WITH LAF/IND BEING ON THE WESTERN FRINGE...DECIDED TO KEEP THEM
VFR. NOT CURRENTLY DEALING WITH MUCH CLOUD COVER OVER HUF/BMG.
HOWEVER...WOULD NOT BE SURPRISED IF BMG GOES SCATTERED THIS
AFTERNOON. EXPECT THIS BAND OF CLOUDS FROM LAF TO IND AND EASTWARD
TO SCATTER LATER THIS AFTERNOON AND EVENING AS DRIER AIR MOVES IN.

THEN THE FOCUS TURNS TO SATURDAY AFTERNOON AND THE APPROACH OF THE
NEXT WEATHER SYSTEM. EXPECT SOME LOWER CEILINGS TO MOVE INTO THE
AREA TOWARD THE END OF THE TAF CYCLE. HOWEVER...DO BELIEVE THAT THE
LOWER MVFR/IFR CEILINGS WILL HOLD OFF UNTIL AFTER THIS PARTICULAR
TAF CYCLE.

AS HIGH PRESSURE CONTINUES TO APPROACH FROM THE WEST...EXPECT NORTH
WINDS TO CONTINUE TO DECREASE AND BECOME LIGHT TONIGHT. INCREASING
BACK TO AROUND 8 TO 10 KNOTS OUT OF THE SOUTHWEST SATURDAY
AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 302153
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
453 PM EST FRI JAN 30 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 301800Z TAF CYCLE/...

ISSUED AT 1257 PM EST FRI JAN 30 2015

EXPECT VFR CONDITIONS TO CONTINUE...BUT JUST BARELY...AT ALL TAF
SITES DURING THIS CYCLE. CURRENT DECK OF CLOUDS OVER LAF/IND ARE
JUST SLIGHTLY IN THE VFR CATEGORY WITH BKN/OVR CEILINGS IN THE
3100 TO 3300 FOOT RANGE. THERE ARE A COUPLE OBS UPSTREAM OF THESE
TWO SITES THAT ARE DEPICTING CEILINGS AT OR BELOW 3000 FEET...HOWEVER
THOSE SITES ARE MORE ENTRENCHED WITHIN THE CURRENT CLOUD MASS.
WITH LAF/IND BEING ON THE WESTERN FRINGE...DECIDED TO KEEP THEM
VFR. NOT CURRENTLY DEALING WITH MUCH CLOUD COVER OVER HUF/BMG.
HOWEVER...WOULD NOT BE SURPRISED IF BMG GOES SCATTERED THIS
AFTERNOON. EXPECT THIS BAND OF CLOUDS FROM LAF TO IND AND EASTWARD
TO SCATTER LATER THIS AFTERNOON AND EVENING AS DRIER AIR MOVES IN.

THEN THE FOCUS TURNS TO SATURDAY AFTERNOON AND THE APPROACH OF THE
NEXT WEATHER SYSTEM. EXPECT SOME LOWER CEILINGS TO MOVE INTO THE
AREA TOWARD THE END OF THE TAF CYCLE. HOWEVER...DO BELIEVE THAT THE
LOWER MVFR/IFR CEILINGS WILL HOLD OFF UNTIL AFTER THIS PARTICULAR
TAF CYCLE.

AS HIGH PRESSURE CONTINUES TO APPROACH FROM THE WEST...EXPECT NORTH
WINDS TO CONTINUE TO DECREASE AND BECOME LIGHT TONIGHT. INCREASING
BACK TO AROUND 8 TO 10 KNOTS OUT OF THE SOUTHWEST SATURDAY
AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 302153
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
453 PM EST FRI JAN 30 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 301800Z TAF CYCLE/...

ISSUED AT 1257 PM EST FRI JAN 30 2015

EXPECT VFR CONDITIONS TO CONTINUE...BUT JUST BARELY...AT ALL TAF
SITES DURING THIS CYCLE. CURRENT DECK OF CLOUDS OVER LAF/IND ARE
JUST SLIGHTLY IN THE VFR CATEGORY WITH BKN/OVR CEILINGS IN THE
3100 TO 3300 FOOT RANGE. THERE ARE A COUPLE OBS UPSTREAM OF THESE
TWO SITES THAT ARE DEPICTING CEILINGS AT OR BELOW 3000 FEET...HOWEVER
THOSE SITES ARE MORE ENTRENCHED WITHIN THE CURRENT CLOUD MASS.
WITH LAF/IND BEING ON THE WESTERN FRINGE...DECIDED TO KEEP THEM
VFR. NOT CURRENTLY DEALING WITH MUCH CLOUD COVER OVER HUF/BMG.
HOWEVER...WOULD NOT BE SURPRISED IF BMG GOES SCATTERED THIS
AFTERNOON. EXPECT THIS BAND OF CLOUDS FROM LAF TO IND AND EASTWARD
TO SCATTER LATER THIS AFTERNOON AND EVENING AS DRIER AIR MOVES IN.

THEN THE FOCUS TURNS TO SATURDAY AFTERNOON AND THE APPROACH OF THE
NEXT WEATHER SYSTEM. EXPECT SOME LOWER CEILINGS TO MOVE INTO THE
AREA TOWARD THE END OF THE TAF CYCLE. HOWEVER...DO BELIEVE THAT THE
LOWER MVFR/IFR CEILINGS WILL HOLD OFF UNTIL AFTER THIS PARTICULAR
TAF CYCLE.

AS HIGH PRESSURE CONTINUES TO APPROACH FROM THE WEST...EXPECT NORTH
WINDS TO CONTINUE TO DECREASE AND BECOME LIGHT TONIGHT. INCREASING
BACK TO AROUND 8 TO 10 KNOTS OUT OF THE SOUTHWEST SATURDAY
AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIND 302153
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
453 PM EST FRI JAN 30 2015

.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 348 PM EST FRI JAN 30 2015

THE MAIN FOCUS OF THE FORECAST PERIOD WILL BE A STORM SYSTEM
PROJECTED TO IMPACT THE AREA MAINLY EARLY SUNDAY THROUGH SUNDAY
NIGHT. MODELS HAVE THE SYSTEM APPROACHING FROM THE SOUTHWEST AND
IT IS EXPECTED TO BRING ACCUMULATING SNOWFALL BEGINNING LATE
SATURDAY NIGHT AND CONTINUING BEFORE EXITING THE REGION MONDAY MORNING.
IN THE WAKE OF THE SYSTEM...BELOW NORMAL TEMPERATURES WILL PREVAIL
ON MONDAY WITH HIGHS ONLY IN THE TEENS. ADDITIONAL PRECIPITATION
CHANCES WILL BE POSSIBLE ON TUESDAY NIGHT AND WEDNESDAY AS A COLD
FRONT MOVES THROUGH CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 348 PM EST FRI JAN 30 2015

FAIRLY QUIET NIGHT TONIGHT...AHEAD THIS LATE WEEKEND/S STORM. HIGH
PRESSURE WILL SLIDE TO THE EAST OF THE AREA. MOSTLY CLEAR SKIES
TONIGHT AND A BLEND OF GUIDANCE FOR TEMPERATURES SEEMS REASONABLE
FOR LOWS IN THE MID TEENS (NORTH) TO LOW 20S (SOUTH).

&&

.SHORT TERM /SATURDAY THROUGH MONDAY/...

ISSUED AT 348 PM EST FRI JAN 30 2015

AS MENTIONED IN UPDATE TO FORECAST EARLIER THIS AFTERNOON A WINTER
STORM WATCH WAS ISSUED FOR ALL COUNTIES ACROSS THE FORECAST AREA...EXCEPT
FOR THE SOUTHERN TWO TIER OF COUNTIES.

THERE IS MEDIUM CONFIDENCE IN THE FORECAST FOR THIS STORM.
YES...DEPENDING ON ANY GIVEN ONE LOCATION...SOME OF THE MODELS
DIFFER WIDELY ON PRECIP/SNOW AMOUNTS WITH ANYTHING FROM 1-2 INCHES TO A
FOOT OF SNOW. HOWEVER THERE IS STILL CONSENSUS AND SOME CONSISTENCY WITH
REGARD TO THE THE MOVEMENT OF THE LOW THROUGH THE OHIO VALLEY AND
THE TIMING OF THE EVENT.

THE MODEL GUIDANCE/SUITE AS A WHOLE HAS TRENDED NORTHWARD AND WETTER
FOR THE MOST PART...SAVE FOR THE GFS WHICH CAME IN SLIGHTLY DRIER
THIS RUN. TIMING LOOKS STILL TO BE BEGIN SATURDAY EVENING AND
LASTING UNTIL THE EARLY HOURS OF MONDAY MORNING...BEFORE THE SYSTEM
FINALLY PULLS AWAY FROM THE CWA. SO THIS IS A FAIRLY LONG DURATION
SNOW EVENT.

THERE IS A SHARP GRADIENT CUT-OFF WITH POPS WHICH ONCE AGAIN
MYSTERIOUSLY FALLS ROUGHLY ALONG/AROUND THE I-70 CORRIDOR...A
PHENOMENON IN WHICH FORECASTERS IN CENTRAL INDIANA ARE QUITE
FAMILIAR WITH. THE WINTER STORM WATCH WAS ISSUED FOR AROUND THIS
CUT-OFF ZONE AND NORTHWARD. AND THIS WAS BASED ON AN AVERAGE OF THE
THE EURO/SREF/NAM AND GFS AMOUNTS WHICH ARE IN GOOD/SIMILAR
AGREEMENT AND AMOUNTED TO A MEAN OF 6-9 INCHES BEING POSSIBLE
WITHIN THE WATCH AREA...AT THIS TIME OF ISSUANCE. WITH OF COURSE THE
HIGHEST AMOUNTS ACROSS THE NORTHERN COUNTY WARNING AREA.

OTHER THAN THE HEAVIER SNOW AMOUNTS BEING THE BIG STORY...THE
OTHER SIGNIFICANT STORY IS THE COUNTIES FOR SOUTH OF THE WATCH
AREA. AS THE GUIDANCE CAME IN THIS ROUND WITH A NORTHWARD
TREND...IT IS ALSO MUCH WARMER THAN PREVIOUSLY FORECAST. FIRST...A
FEW LIGHT RAIN SHOWERS MAY BE POSSIBLE BEFORE THIS SYSTEM EVEN ARRIVES
SATURDAY EVENING AND THE PRECIPITATION TYPE ON SATURDAY NIGHT INTO
EARLY SUNDAY LOOKS TO BE ALL SNOW. HOWEVER...SURFACE TEMPERATURES
AND THICKNESSES HAVE WARMED SO THAT A SNOW/RAIN MIX IS NOW POSSIBLE
ACROSS THE SOUTHERN COUNTIES MAINLY DURING SUNDAY AFTERNOON. THIS
WAS ACCOUNTED FOR AND THE FORECAST WAS UPDATED TO REFLECT SNOW
LIKELY WITH A CHANCE OF RAIN MIXING IN SUNDAY AFTERNOON/EARLY
EVENING. THIS WILL KNOCK DOWN SNOW TOTALS ACROSS THIS AREA
CONSIDERABLY...TO 1-4 INCHES...WHICH IS QUITE A DIFFERENCE FROM THE SNOW
TOTALS PREDICTED IN THE WATCH AREA...HENCE THE SHARP SNOWFALL
GRADIENT CUT-OFF MENTIONED EARLY. FOR NOW WILL MENTION THIS IN THE
HWO AND THE WX STORY AS THIS DOES NOT WARRANT ANY TYPE OF
STATEMENT AT THIS TIME.

FINALLY...THE SYSTEM LOOKS TO MOVE AWAY FROM THE AREA BY MONDAY
MORNING AND THE FORECAST FOR THE REST OF THE DAY LOOKS DRY. IT
DOES NOT APPEAR ANY WRAP AROUND SNOW SHOWERS OR FLURRIES ARE EVEN
POSSIBLE BY THE WAY THE THE SYSTEM APPEARS TO ACCELERATE FROM THE
AREA AND COLDER AND MUCH DRIER AIR (COLD AIR ADVECTION) BEGINS TO
FLOW OVER THE AREA IN EARNEST BY MONDAY AFTERNOON AND EVENING.

&&

.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...

ISSUED AT 204 PM EST FRI JAN 30 2015

ECMWF AND GFS AGREE ON A PERSISTENT COLD PATTERN AS NORTHWEST FLOW
IS PERSISTENT ALOFT. IN THE WAKE OF THE COLD FRONT ON MONDAY THE
FIRST OF TWO ARCTIC AIR MASSES IS EXPECTED TO SETTLE ACROSS THE
OHIO VALLEY...BRINGING DRY AND COLD WEATHER.

A WEAK COLD FRONT IS EXPECTED TO PUSH ACROSS THE AREA ON
WEDNESDAY...HOWEVER THE AIR MASS AHEAD AND BEHIND THIS SYSTEM
REMAIN QUITE DRY. FURTHERMORE...DYNAMICS ALOFT APPEAR VERY
LIMITED. THUS AS THIS SYSTEM PASSES ANY SNOWFALL THAT WILL OCCUR
SHOULD BE LIGHT. IN THE WAKE OF THE COLD FRONT YET ANOTHER ARCTIC
HIGH PRESSURE SYSTEM IS SET TO MOVE IN TO THE AREA...WITH ANOTHER
BLAST OF COLD AIR ADVECTION.

GIVEN THE COLD AIR ADVECTION THROUGH THE PERIOD AND THE
EXPECTATION OF SNOW ON THE GROUND FROM PREVIOUS SYSTEMS...HAVE
TRENDED TEMPS COOLER THAN MAVMOS.

&&

.AVIATION /DISCUSSION FOR THE 301800Z TAF CYCLE/...

ISSUED AT 1257 PM EST FRI JAN 30 2015

EXPECT VFR CONDITIONS TO CONTINUE...BUT JUST BARELY...AT ALL TAF
SITES DURING THIS CYCLE. CURRENT DECK OF CLOUDS OVER LAF/IND ARE
JUST SLIGHTLY IN THE VFR CATEGORY WITH BKN/OVR CEILINGS IN THE
3100 TO 3300 FOOT RANGE. THERE ARE A COUPLE OBS UPSTREAM OF THESE
TWO SITES THAT ARE DEPICTING CEILINGS AT OR BELOW 3000 FEET...HOWEVER
THOSE SITES ARE MORE ENTRENCHED WITHIN THE CURRENT CLOUD MASS.
WITH LAF/IND BEING ON THE WESTERN FRINGE...DECIDED TO KEEP THEM
VFR. NOT CURRENTLY DEALING WITH MUCH CLOUD COVER OVER HUF/BMG.
HOWEVER...WOULD NOT BE SURPRISED IF BMG GOES SCATTERED THIS
AFTERNOON. EXPECT THIS BAND OF CLOUDS FROM LAF TO IND AND EASTWARD
TO SCATTER LATER THIS AFTERNOON AND EVENING AS DRIER AIR MOVES IN.

THEN THE FOCUS TURNS TO SATURDAY AFTERNOON AND THE APPROACH OF THE
NEXT WEATHER SYSTEM. EXPECT SOME LOWER CEILINGS TO MOVE INTO THE
AREA TOWARD THE END OF THE TAF CYCLE. HOWEVER...DO BELIEVE THAT THE
LOWER MVFR/IFR CEILINGS WILL HOLD OFF UNTIL AFTER THIS PARTICULAR
TAF CYCLE.

AS HIGH PRESSURE CONTINUES TO APPROACH FROM THE WEST...EXPECT NORTH
WINDS TO CONTINUE TO DECREASE AND BECOME LIGHT TONIGHT. INCREASING
BACK TO AROUND 8 TO 10 KNOTS OUT OF THE SOUTHWEST SATURDAY
AFTERNOON.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SATURDAY EVENING THROUGH MONDAY MORNING
FOR INZ021-028>031-035>049-051>057.

&&

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM....PUMA
AVIATION...MRD

VISIT US AT HTTP://WWW.WEATHER.GOV/IND

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS








000
FXUS63 KIWX 302118 CCA
AFDIWX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE NORTHERN INDIANA
417 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 302118 CCA
AFDIWX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE NORTHERN INDIANA
417 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 302118 CCA
AFDIWX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE NORTHERN INDIANA
417 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 302118 CCA
AFDIWX

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE NORTHERN INDIANA
417 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...FISHER
LONG TERM...MURPHY
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA









000
FXUS63 KIWX 302108
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
408 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIWX 302108
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
408 PM EST FRI JAN 30 2015

.SYNOPSIS...
ISSUED AT 405 PM EST FRI JAN 30 2015

LAKE EFFECT CLOUDS AND FLURRIES WILL CONTINUE TO DIMINISH THIS
EVENING AS HIGH PRESSURE BUILDS ACROSS THE REGION. LOW
TEMPERATURES TONIGHT WILL DROP BACK INTO THE TEENS. HIGHS ON
SATURDAY WILL BE IN THE 30S. A DEVELOPING WINTER STORM WILL
IMPACT THE REGION STARTING SATURDAY NIGHT AND CONTINUING INTO
SUNDAY. WINTER STORM WATCHES REMAIN IN EFFECT.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 PM EST FRI JAN 30 2015

BENIGN WEATHER EXPECTED THROUGH SATURDAY AS HIGH PRESSURE DRIFTS
ACROSS THE REGION. BANDS OF LAKE EFFECT CLOUDS AND FLURRIES HAVE
BEEN STEADILY CONTRACTING PAST COUPLE OF HOURS WITH THIS TREND
LIKELY TO INCREASE AS WE CLOSE IN ON THE EARLY EVENING HOURS. THE
CLEAR SKIES AND DIMINISHING WINDS WILL ALLOW LOWS TO DROP INTO
THE TEENS AS THE HIGH DRIFTS OVERHEAD.

THE REGION WILL BE ON THE WARM SIDE OF THE HIGH ON SATURDAY
ALLOWING AFTERNOON HIGHS TO CLIMB TO NEAR OR ABOVE
FREEZING...ALLOWING FOR TEMPORARILY IMPROVING ROAD CONDITIONS
PRIOR TO THE ARRIVAL OF THE SNOW SATURDAY EVENING.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 PM EST FRI JAN 30 2015

12 UTC MODELS/COBB OUTPUT ALONG WITH 09/15 UTC SREF ENSEMBLE
PLUMES LENDING INCREASED CONFIDENCE FOR SIG EVENT SAT NIGHT
THROUGH SUN NIGHT...LEADING TO PRIOR MIDDAY ISSUANCE OF WINTER
STORM WATCH FOLLOWING WPC/INTEROFFICE COORD. SW/BAJA VORTEX
PUMPING EXTREME MOISTURE TRANSPORT NWD. 4-6 G/KG PLUS WITHIN
850-500 MB EXTRUDED NWD FM SWRN MEXICO INTO INTMTN/CENTRAL ROCKIES
TO HARMONIOUSLY MELD WITH HIGH MOISTURE LADEN WRN VANCOUVER WAVE
INTO SAT. PRESENCE OF HUDSON BAY AND SWRN VORTEX TO AID IN PHASING
TO SHARPLY HEWN SEWD DIVING SHORTWAVE THROUGH NRN PLAINS INTO MID
MS VLY. INCREASINGLY RAMPED HGHT FALLS WITH LONG DURATION TO AID
IN LARGE SCALE ASCENT. PROLONGED EWD REACH OF HGHT ADJUSTMENTS
NOTED AS HFC IN EXCESS OF 100M/12HR SUN AM INTENSIFIES UPWARDS OF
180M/12 HR AS IT INTO SWRN OH/NRN KY BY 12 UTC MON.
EXTREME/PROLONGED MFLUX CONVERGENCE IN E-W FASHION THROUGH NRN IL
INTO NWRN OH PER I285/I290K NAM ISENTROPIC SFCS. 50 KT SWRLY
JETLET ORTHOGONAL TO ISENT SFCS MOVES EWD FM SERN MO UP OHIO BASIN
SUN AM TO NEAR KCVG BY 00 UTC MON. 7H TRACK IN LARGELY
OPEN/POSITIVE TILT TO WEAKLY CLOSED ALONG ROUTE 6 CORRIDOR AND
HINT OF TROWAL AT I285K JUST SOUTH...ALONG WITH TIGHTER ENSEMBLE
SPREAD LENDS HIR CONFIDENCE TO FARTHER NWD SWATH OF HEAVIEST
SNOWFALL. WHILE CONFIDENCE OF SIG EVENT/6 PLUS INCHES IS VERY
HIGH...EVENTUAL PLACEMENT AND DETAILS ALONG N/S GRADIENT EDGES
STILL EVOKE HESITANCE/UNCERTAINTY. THEREFORE ENTIRE CWA UNDER WSW
FOR 6 TO 12 INCHES POSSIBLE...WITH LATER RUNS PROVIDING SUFFICIENT
CONFIDENCE FOR UPG WARNING/ADV DECISIONS...LIKELY EARLY AM SUN AND
CERTAINLY BY NOON SHOULD DEFERENCE BE MADE TO 12 UTC SUN MODEL
OUTPUT. WHAT COULD GO WRONG...INCLUSION OF PLATES/NEEDLES IN DEEP
SUPERSATURATION ABOVE THE DGZ COULD LEAD TO MORE GRANULAR FLAKES
AND ANY FARTHER NWD TREND WOULD BEGIN TO GREATLY LESSEN FAR SRN
CWA SLR AS COLUMN WARMS...THOUGH SRN CWA NAM BUFKIT SITES FIRM IN
FROZEN/SNOW PTYPE PER ENERGY NOMOGRAM. RAMPED GRADIENT FLOW TO
BRING PD OF BLSN ESP LATE SUN AFTN/EVE AS OH VLY SFC LOW DEEPENS
ALONG TRACK THROUGH MID INTO UPR OH VLY.

BRIEF LES IN WAKE OF SYSTEM...THOUGH INITIAL BAND MAY SET WEST OF
CWA UNTIL BACKING FLOW BY DAYBREAK MON. THEREAFTER DRY AIR
INTRUSION ALONG WITH LOWERING/STRENGTHENING SUBSIDENCE INVERSION
SHOULD GREATLY MITIGATE NWRN CWA ACCUMS. WEAK CLIPPER SYSTEM INTO
GRTLKS TUE NIGHT/WED...FOLLOWED AGAIN BY AT LEAST WEAK LES
RESPONSE AS PRIMARY TROF AXIS SHARPENS FM HUDSON BAY INTO LWR
GRTLKS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1245 PM EST FRI JAN 30 2015

MARGINAL MVFR CIGS WILL PERSIST AT KSBN THROUGH THE AFTERNOON WITH
EVENTUAL TREND TO CLEARING SKIES TONIGHT. RADAR RETURNS AND SFC
REPORTS SHOWING LITTLE MORE THAN FLURRIES HERE AND THERE SO NO
VSBY IMPACTS EXPECTED.

AFTER 00Z SAT LITTLE IN THE WAY OF SENSIBLE WEATHER CONCERNS AS
HIGH PRESSURE DOMINATES.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR INZ003>009-012>018-020-022>027-032>034.

MI...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR MIZ077>081.

OH...WINTER STORM WATCH FROM SATURDAY EVENING THROUGH SUNDAY EVENING
     FOR OHZ001-002-004-005-015-016-024-025.

LM...NONE.
&&

$$

SYNOPSIS...MURPHY
SHORT TERM...MARSILI
LONG TERM...SKIPPER
AVIATION...FISHER


VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







    US Dept of Commerce
    National Oceanic and Atmospheric Administration
    National Weather Service
    1325 East West Highway
    Silver Spring, MD 20910
    Page Author: NWS Internet Services Team
Disclaimer
Information Quality
Credits
Glossary
Privacy Policy
Freedom of Information Act (FOIA)
About Us
Career Opportunities