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000
FXUS63 KIND 201743
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1243 PM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1800Z TAF ISSUANCE/...

ISSUED AT 1232 PM EST SAT DEC 20 2014

PERSISTENT LOW LEVEL CLOUD DECK CONTINUES TO AFFECT TAF SITES.
MVFR/VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD
DESPITE HIGH PRESSURE OVER THE AREA. TIME CROSS SECTIONS CONTINUE
TO SHOW SUBSTANTIAL LOW LEVEL MOISTURE. VARIABLE WINDS WILL BECOME
MAINLY SOUTHEASTERLY TONIGHT WITH SUSTAINED SPEEDS OF 2 TO 4 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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 201743
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1243 PM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1800Z TAF ISSUANCE/...

ISSUED AT 1232 PM EST SAT DEC 20 2014

PERSISTENT LOW LEVEL CLOUD DECK CONTINUES TO AFFECT TAF SITES.
MVFR/VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD
DESPITE HIGH PRESSURE OVER THE AREA. TIME CROSS SECTIONS CONTINUE
TO SHOW SUBSTANTIAL LOW LEVEL MOISTURE. VARIABLE WINDS WILL BECOME
MAINLY SOUTHEASTERLY TONIGHT WITH SUSTAINED SPEEDS OF 2 TO 4 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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 201743
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1243 PM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1800Z TAF ISSUANCE/...

ISSUED AT 1232 PM EST SAT DEC 20 2014

PERSISTENT LOW LEVEL CLOUD DECK CONTINUES TO AFFECT TAF SITES.
MVFR/VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD
DESPITE HIGH PRESSURE OVER THE AREA. TIME CROSS SECTIONS CONTINUE
TO SHOW SUBSTANTIAL LOW LEVEL MOISTURE. VARIABLE WINDS WILL BECOME
MAINLY SOUTHEASTERLY TONIGHT WITH SUSTAINED SPEEDS OF 2 TO 4 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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 201743
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1243 PM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1800Z TAF ISSUANCE/...

ISSUED AT 1232 PM EST SAT DEC 20 2014

PERSISTENT LOW LEVEL CLOUD DECK CONTINUES TO AFFECT TAF SITES.
MVFR/VFR CONDITIONS WILL PREVAIL FOR DURATION OF TAF PERIOD
DESPITE HIGH PRESSURE OVER THE AREA. TIME CROSS SECTIONS CONTINUE
TO SHOW SUBSTANTIAL LOW LEVEL MOISTURE. VARIABLE WINDS WILL BECOME
MAINLY SOUTHEASTERLY TONIGHT WITH SUSTAINED SPEEDS OF 2 TO 4 KTS.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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 201715
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1215 PM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1210 PM EST SAT DEC 20 2014

LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH INVERSION RESULTING IN
PERSISTENT LOW CLOUDS AND SOME BR ACROSS NE INDIANA WHERE A LITTLE
BETTER RADIATIONAL COOLING OCCURRED LAST NIGHT. WK SHRTWV MOVG
ACROSS THE AREA THIS AFTN MAY CAUSE A FEW FLURRIES BUT PRBLY NOT
HAVE A SGFNT IMPACT ON VSBYS SO LEFT OUT OF TAF. LITTLE CHANGE
EXPECTED THIS TAF PERIOD WITH MVFR/LOW VFR CIGS PERSISTING AND
VSBYS OVER NE INDIANA LIKELY LOWERING AGAIN BY SUNDAY MORNING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
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 201715
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1215 PM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1210 PM EST SAT DEC 20 2014

LOW LEVEL MOISTURE REMAINS TRAPPED BENEATH INVERSION RESULTING IN
PERSISTENT LOW CLOUDS AND SOME BR ACROSS NE INDIANA WHERE A LITTLE
BETTER RADIATIONAL COOLING OCCURRED LAST NIGHT. WK SHRTWV MOVG
ACROSS THE AREA THIS AFTN MAY CAUSE A FEW FLURRIES BUT PRBLY NOT
HAVE A SGFNT IMPACT ON VSBYS SO LEFT OUT OF TAF. LITTLE CHANGE
EXPECTED THIS TAF PERIOD WITH MVFR/LOW VFR CIGS PERSISTING AND
VSBYS OVER NE INDIANA LIKELY LOWERING AGAIN BY SUNDAY MORNING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
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 201511
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1011 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.


&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1500Z TAF UPDATE/...

ISSUED AT 924 AM EST SAT DEC 20 2014

UPDATE...
CONDITIONS CONTINUE TO HOVER AT THE MVFR/VFR MARK AT KIND.

PREVIOUS DISCUSSION...
MVFR/VFR STRATUS TO PERSIST THROUGH THIS EVENING.

WEAK WAVE ALOFT QUICKLY SHIFTING EAST OF THE REGION EARLY THIS
MORNING AFTER PRODUCING A FEW HOURS OF LIGHT SNOW AT KBMG. DESPITE
SURFACE HIGH PRESSURE BUILDING INTO THE REGION TODAY...THICK
STRATUS DECK SHOWING NO SIGNS OF ABATING. LIGHT NORTHEAST FLOW
THROUGH THE BOUNDARY LAYER AND PRESENCE OF A LOW LEVEL INVERSION
WILL HELP TO MAINTAIN THE CLOUD DECK ALL DAY...WITH CEILINGS
VARYING BETWEEN 2500-3500FT IN GENERAL. DRIER AIR TRIES TO BUILD
INTO THE NEAR SURFACE LAYER TONIGHT...AND AT THE VERY LEAST SHOULD
ENABLE SOME SCATTERING OF THE STRATUS DECK TO A HIGHER CLOUD BASE.
LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 201511
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1011 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM /THIS AFTERNOON/...

ISSUED AT 952 AM EST SAT DEC 20 2014

SURFACE ANALYSIS WEAK HIGH PRESSURE IN PLACE ACROSS INDIANA...OHIO
AND THE TENNESSEE VALLEY. SATELLITE SHOW EXTENSIVE CLOUDINESS IN
PLACE ACROSS INDIANA. ALOFT A SHORT WAVE WAS EXITING THE AREA AND
RADAR WAS NOW QUIET AS SNOW SHOWERS ACROSS THE SOUTHEAST HAVE
EXITED THE FORECAST AREA.

TIME HEIGHTS CONTINUE TO SHOW SATURATED LOWER LEVELS THROUGH
TONIGHT AND INTO SUNDAY. GIVEN THIS...AND THE MODELS CONTINUING TO
HAVE DIFFICULTY IN HANDLING THE LOWER LEVEL MOISTURE...ALONG WITH
SATELLITE SHOWING EXTENSIVE CLOUDS ACROSS THE REGION...WILL
CONTINUE WITH A CLOUDY FORECAST.

GIVEN THE LACK OF SUN AND ONGOING WEAK COLD AIR ADVECTION...HAVE
TREND HIGHS COOLER...TOWARD THE 3 HOURLY VALUES OF THE MAVMOS.


&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1500Z TAF UPDATE/...

ISSUED AT 924 AM EST SAT DEC 20 2014

UPDATE...
CONDITIONS CONTINUE TO HOVER AT THE MVFR/VFR MARK AT KIND.

PREVIOUS DISCUSSION...
MVFR/VFR STRATUS TO PERSIST THROUGH THIS EVENING.

WEAK WAVE ALOFT QUICKLY SHIFTING EAST OF THE REGION EARLY THIS
MORNING AFTER PRODUCING A FEW HOURS OF LIGHT SNOW AT KBMG. DESPITE
SURFACE HIGH PRESSURE BUILDING INTO THE REGION TODAY...THICK
STRATUS DECK SHOWING NO SIGNS OF ABATING. LIGHT NORTHEAST FLOW
THROUGH THE BOUNDARY LAYER AND PRESENCE OF A LOW LEVEL INVERSION
WILL HELP TO MAINTAIN THE CLOUD DECK ALL DAY...WITH CEILINGS
VARYING BETWEEN 2500-3500FT IN GENERAL. DRIER AIR TRIES TO BUILD
INTO THE NEAR SURFACE LAYER TONIGHT...AND AT THE VERY LEAST SHOULD
ENABLE SOME SCATTERING OF THE STRATUS DECK TO A HIGHER CLOUD BASE.
LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...PUMA
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 201428
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
928 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1500Z TAF UPDATE/...

ISSUED AT 924 AM EST SAT DEC 20 2014

UPDATE...
CONDITIONS CONTINUE TO HOVER AT THE MVFR/VFR MARK AT KIND.

PREVIOUS DISCUSSION...
MVFR/VFR STRATUS TO PERSIST THROUGH THIS EVENING.

WEAK WAVE ALOFT QUICKLY SHIFTING EAST OF THE REGION EARLY THIS
MORNING AFTER PRODUCING A FEW HOURS OF LIGHT SNOW AT KBMG. DESPITE
SURFACE HIGH PRESSURE BUILDING INTO THE REGION TODAY...THICK
STRATUS DECK SHOWING NO SIGNS OF ABATING. LIGHT NORTHEAST FLOW
THROUGH THE BOUNDARY LAYER AND PRESENCE OF A LOW LEVEL INVERSION
WILL HELP TO MAINTAIN THE CLOUD DECK ALL DAY...WITH CEILINGS
VARYING BETWEEN 2500-3500FT IN GENERAL. DRIER AIR TRIES TO BUILD
INTO THE NEAR SURFACE LAYER TONIGHT...AND AT THE VERY LEAST SHOULD
ENABLE SOME SCATTERING OF THE STRATUS DECK TO A HIGHER CLOUD BASE.
LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 201428
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
928 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 20/1500Z TAF UPDATE/...

ISSUED AT 924 AM EST SAT DEC 20 2014

UPDATE...
CONDITIONS CONTINUE TO HOVER AT THE MVFR/VFR MARK AT KIND.

PREVIOUS DISCUSSION...
MVFR/VFR STRATUS TO PERSIST THROUGH THIS EVENING.

WEAK WAVE ALOFT QUICKLY SHIFTING EAST OF THE REGION EARLY THIS
MORNING AFTER PRODUCING A FEW HOURS OF LIGHT SNOW AT KBMG. DESPITE
SURFACE HIGH PRESSURE BUILDING INTO THE REGION TODAY...THICK
STRATUS DECK SHOWING NO SIGNS OF ABATING. LIGHT NORTHEAST FLOW
THROUGH THE BOUNDARY LAYER AND PRESENCE OF A LOW LEVEL INVERSION
WILL HELP TO MAINTAIN THE CLOUD DECK ALL DAY...WITH CEILINGS
VARYING BETWEEN 2500-3500FT IN GENERAL. DRIER AIR TRIES TO BUILD
INTO THE NEAR SURFACE LAYER TONIGHT...AND AT THE VERY LEAST SHOULD
ENABLE SOME SCATTERING OF THE STRATUS DECK TO A HIGHER CLOUD BASE.
LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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

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







000
FXUS63 KIND 201033
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
533 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR 201200Z TAF ISSUANCE/...
ISSUED AT 533 AM EST SAT DEC 20 2014

MVFR/VFR STRATUS TO PERSIST THROUGH THIS EVENING.

WEAK WAVE ALOFT QUICKLY SHIFTING EAST OF THE REGION EARLY THIS
MORNING AFTER PRODUCING A FEW HOURS OF LIGHT SNOW AT KBMG. DESPITE
SURFACE HIGH PRESSURE BUILDING INTO THE REGION TODAY...THICK
STRATUS DECK SHOWING NO SIGNS OF ABATING. LIGHT NORTHEAST FLOW
THROUGH THE BOUNDARY LAYER AND PRESENCE OF A LOW LEVEL INVERSION
WILL HELP TO MAINTAIN THE CLOUD DECK ALL DAY...WITH CEILINGS
VARYING BETWEEN 2500-3500FT IN GENERAL. DRIER AIR TRIES TO BUILD
INTO THE NEAR SURFACE LAYER TONIGHT...AND AT THE VERY LEAST SHOULD
ENABLE SOME SCATTERING OF THE STRATUS DECK TO A HIGHER CLOUD BASE.
LIGHT AND VARIABLE WINDS EXPECTED THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIWX 201027
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
527 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 201027
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
527 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 524 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 200830
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 200900Z TAF UPDATE/...
ISSUED AT 330 AM EST SAT DEC 20 2014

LIGHT SNOW LIKELY TO IMPACT KBMG FOR ANOTHER HOUR OR TWO WITH
VISIBILITIES DOWN TO 2SM PERIODICALLY. A FEW FLAKES MAY FLY
BRIEFLY AT KIND BUT SHOULD NOT CAUSE ANY RESTRICTIONS. MADE MINOR
TWEAKS TO CEILINGS BASED ON OBS OTHERWISE NO ADDITIONAL CHANGES
NEEDED.

06Z DISCUSSION FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MVFR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...SMF/RYAN

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIND 200830
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /TUESDAY THROUGH FRIDAY/...
ISSUED AT 330 AM EST SAT DEC 20 2014

ACTIVE WEATHER PATTERN THROUGH THE EXTENDED WITH FOCUS REMAINING ON
EXPECTED DEVELOPMENT OF AN INTENSE STORM SYSTEM OVER THE GREAT LAKES
BY WEDNESDAY BRINGING A MYRIAD OF WEATHER IMPACTS TO CENTRAL INDIANA
JUST IN TIME FOR CHRISTMAS.

SHARP UPPER RIDGE AXIS WILL BE ALIGNED JUST OFF THE PACIFIC COAST
TUESDAY MORNING...AND THIS WILL ENCOURAGE AMPLIFICATION OF A
DOWNSTREAM TROUGH EAST OF THE ROCKIES AS A POWERFUL POLAR JET RIDES
OVERTOP OF THE RIDGE AND CARVES OUT A PROGRESSIVELY DEEPER TROUGH.
THE POLAR JET ENERGY WILL INTERACT WITH THE SUBTROPICAL JET LIFTING
OUT OF THE GULF OF MEXICO BY TUESDAY NIGHT...PROMPTING RAPID
CYCLOGENESIS OVER THE REGION AS LOW PRESSURE OVER THE GREAT LAKES
LINKS UP WITH A SECONDARY LOW LIFTING NORTHEAST FROM THE LOWER
MISSISSIPPI VALLEY.

THE PRESENCE OF THE PRIMARY LOW APPROACHING FROM THE NORTHWEST AND
SOUTHERLY FLOW AHEAD OF IT WILL TRANSPORT DEEP MOISTURE INTO THE
OHIO VALLEY WITH WIDESPREAD RAIN ANTICIPATED ALL DAY TUESDAY. THE
PHASING OF THE JET ENERGY ALOFT WILL BEGIN LATE TUESDAY WITH A FULL
MERIDIONAL UPPER TROUGH QUICKLY TAKING ON A NEGATIVE TILT. AS STATED
ABOVE...THIS WILL PROMPT A RAPID INTENSIFICATION OF THE SECONDARY
LOW AS IT LIFTS NORTH AND ABSORBS THE GREAT LAKES SURFACE WAVE.

INDIVIDUAL MODELS STILL MAINTAIN DIFFERENCES WITH RESPECT TO HOW
QUICKLY THE PHASING OCCURS...RESULTING IN DIFFERENT TRACKS OF THE
SURFACE LOW. GGEM APPEARS TO BE THE FASTEST TO PHASE AND
STRENGTHEN...FOLLOWED BY THE ECMWF WITH THE OP GFS AND MAJORITY OF
ITS ENSEMBLE MEMBERS LAGGING BY 6 HOURS OR SO. TIMING OF THE PHASE
WILL BE CRITICAL IN DETERMINING HOW QUICKLY COLDER AIR CAN ARRIVE
AND CHANGE PRECIPITATION TO SNOW. A FASTER PHASED SYSTEM WILL PULL
THE TRACK OF THE LOW LEFT OR FURTHER WEST PER THE GGEM...WHILE A
SLOWER PHASE WOULD KEEP THE TRACK EAST AS PER THE ECMWF AND OP GFS.
THOSE DETAILS ARE STILL PROBABLY 36 TO 48 HOURS AWAY AT A MINIMUM
FROM BEING ENTIRELY WORKED OUT...BUT OVERALL MODEL CONSENSUS
SUPPORTS SLOWING THE P-TYPE TRANSFER TO LATE TUESDAY NIGHT/WEDNESDAY
MORNING.

CHRISTMAS EVE APPEARS TO BE THE POTENTIAL TRAVEL TROUBLE DAY AT THIS
POINT AS LOW LEVEL THERMALS AND BOUNDARY LAYER TEMPS CRASH WITH
COLDER AIR WRAPPING AROUND THE INTENSIFYING NORTHWARD MOVING LOW
TRACKING INTO THE GREAT LAKES. STILL QUITE A BIT OF UNCERTAINTY AS
TO HOW ROBUST PRECIP RATES WILL BE WITHIN THE COLD POOL WEDNESDAY...
ESPECIALLY WITH DEEPEST FORCING ALOFT ACCOMPANYING THE SURFACE WAVE
AND SETTING UP NORTHEAST OF THE FORECAST AREA. IT REMAINS PREMATURE
TO ADDRESS ANY SNOWFALL ACCUMULATIONS AT THIS TIME...BUT AN INCH OR
TWO CERTAINLY APPEAR PLAUSIBLE WITH THE SCENARIO PRESENTED ABOVE. AS
HAS BEEN MENTIONED...WIND IS LIKELY TO BE THE MORE SIGNIFICANT
IMPACT WITH SUCH AN INTENSE SURFACE LOW MOVING THROUGH THE REGION.
WIND DRIVEN SNOW SHOWERS WITH FALLING TEMPS WEDNESDAY INTO WEDNESDAY
NIGHT IS LIKELY TO CREATE DIFFICULT CONDITIONS FOR TRAVEL ACROSS THE
REGION. THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE
ENCOURAGED TO STAY TUNED IN THE COMING DAYS.

CHRISTMAS DAY LOOKS TO BE QUIET AS HIGH PRESSURE FINALLY ARRIVES IN
THE WAKE OF THE STRONG LOW PRESSURE. YET ANOTHER STORM SYSTEM
DEVELOPING OVER THE HIGH PLAINS WILL SWING INTO THE MIDWEST FOR
FRIDAY. MODELS ARE ALL OVER THE PLACE WITH THE EVOLUTION OF THIS
SYSTEM...BUT RECENT TRENDS SUGGEST THIS FEATURE TO TRACK NORTHWEST
OF THE FORECAST AREA AS WARMER AIR AND RIDGING ALOFT QUICKLY
RETURNS TO CENTRAL INDIANA. WILL CARRY CHANCE POPS FRIDAY FOR RAIN
AS TEMPS RETURN TO THE 40S...WITH COLDER AIR BEING DRAWN BACK INTO
THE OHIO VALLEY NEXT WEEKEND AS THE SYSTEM PASSES.

TO SUM UP IMPACTS AT THIS POINT...RAIN TUESDAY/WIND AND SNOW
WEDNESDAY/QUIET THURSDAY/RAIN FRIDAY. LONG RANGE MODEL TRENDS
SUGGEST ACTIVE PATTERN WILL CONTINUE BEYOND THE 7 DAY.

&&

.AVIATION /DISCUSSION FOR THE 200900Z TAF UPDATE/...
ISSUED AT 330 AM EST SAT DEC 20 2014

LIGHT SNOW LIKELY TO IMPACT KBMG FOR ANOTHER HOUR OR TWO WITH
VISIBILITIES DOWN TO 2SM PERIODICALLY. A FEW FLAKES MAY FLY
BRIEFLY AT KIND BUT SHOULD NOT CAUSE ANY RESTRICTIONS. MADE MINOR
TWEAKS TO CEILINGS BASED ON OBS OTHERWISE NO ADDITIONAL CHANGES
NEEDED.

06Z DISCUSSION FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MVFR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...SMF/RYAN

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIWX 200827
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
327 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
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000
FXUS63 KIWX 200827
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
327 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO SENSIBLE WEATHER CONCERNS THIS PERIOD AS LOW LEVEL RIDGE REMAINS
ANCHORED ACROSS THE REGION. UNFORTUNATELY RIDGE LOOKS TO REMAIN
DIRTY WITH LITTLE IN THE WAY OF FLOW/ADVECTION AND LOW SUN ANGLE
HELPING TO KEEP RESIDUAL BOUNDARY LAYER MOISTURE TRAPPED UNDER
INVERSION. THIS AND MID LEVEL CLOUD COVER/ASCENT ASSOCIATED WITH A
LOWER AMPLITUDE SHORTWAVE DROPPING SOUTHEAST FROM IA/NRN MO TODAY
SHOULD SUPPORT A MAINLY CLOUDY PERIOD (POSSIBLY A FEW FLURRIES)
AND A LIMITED DIURNAL TEMP RANGE.

&&

.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 327 AM EST SAT DEC 20 2014

NO REAL CHANGES IN LONG TERM ONCE AGAIN AS FOCUS REMAINS ON MID
WEEK WINTER STORM. MODELS CONTINUE TO ADVERTISE SAME LARGE SCALE
SYNOPTIC DEVELOPMENT OF A MAJOR STORM SYSTEM IN THE UPPER MIDWEST
AND GREAT LAKES REGION. DIFFERENCES CONTINUE IN THE DETAILS AND
EVOLUTION OF SYSTEM WITH CRITICAL STORM TRACK AND THERMAL DETAILS
STILL YET TO BE SORTED OUT.

POWERFUL 180+ KT JET OVER NORTHERN PACIFIC NEARING WEST COAST TODAY.
RAOB NETWORK TO LIKELY GET A BETTER SAMPLING OVER THE NEXT 24 TO 36
HOURS WHICH MAY HELP RESOLVE SOME OF THE DETAIL DISCREPANCIES. STILL
EXPECT INITIAL LOW TO DEVELOP MONDAY OVER THE MIDWEST WITH
INCREASING SOUTHERLY LOW LEVEL JET AND MOISTURE TRANSPORT INTO OUR
AREA. THERMAL PROFILES STILL WARM SUFFICIENTLY AND SHOULD SEE ALL
RAIN INTO TUESDAY EVENING. JET ENERGY EXPECTED TO AID IN DEVELOPMENT
OF SECOND LOW WITHIN BASE OF LONGWAVE TROUGH TUESDAY NIGHT. MODEL
DISPARITY CONTINUES WITH TRACK OF THIS DEEPENING LOW PRESSURE WHICH
APPROACHES BOMB STATUS WITH MODELS SHOWING 20 TO 25MB OF DEEPENING
BETWEEN 00Z WED AND 00Z THU. TRACK OF THIS NORTHWARD MOVING SURFACE
LOW VARIES FROM EASTERN OHIO TO WESTERN INDIANA. FURTHER EAST TRACK
WILL ALLOW COLDER AIR TO MOVE IN FASTER AND CHANGE PCPN OVER TO SNOW
FOR GREATER ACCUMS WHILE WESTERN TRACK DELAYS COLD AIR AND LIMITS
SNOW ACCUMS. AS MENTIONED BEFORE WITH THESE STRONG DYNAMIC SYSTEMS
TAKING ON A NEGATIVE TILT...WEST IS BEST APPROACH OFTEN WORKS WITH
REGARDS TO SURFACE LOW MOVEMENT. WILL CONTINUE TO RELY ON CONTINUITY
AND FEW CHANGES TO FORECAST WHICH STILL FITS WELL WITH MODEL
CONSENSUS AND ENSEMBLE APPROACH. WILL KEEP PCPN TYPE AS ALL RAIN
THROUGH 06Z WED FOLLOWED BY TRANSITION TO RAIN OR SNOW BY DAYBREAK
WED THEN ALL SNOW WEST ON WED. DID KEEP RAIN OR SNOW MENTION EAST ON
WED GIVEN THERMAL DIFFERENCES AMONG MODELS. AS LOW DEEPENS AND
GRADIENT TIGHTENS...WINDY CONDITIONS WILL DEVELOP LATER WEDNESDAY
AND WED NIGHT.


&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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

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







000
FXUS63 KIND 200800
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
300 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200600Z TAF ISSUANCE/...

ISSUED AT 1200 AM EST SAT DEC 20 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MFVR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD
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 200800
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
300 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200600Z TAF ISSUANCE/...

ISSUED AT 1200 AM EST SAT DEC 20 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MFVR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD
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 200800
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
300 AM EST SAT DEC 20 2014

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

&&

.SYNOPSIS...
ISSUED AT 300 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL KEEP DRY CONDITIONS ACROSS MUCH OF THE AREA
THROUGH THE WEEKEND. A POTENT LOW PRESSURE SYSTEM WILL BRING
PRECIPITATION TO CENTRAL INDIANA MONDAY THROUGH CHRISTMAS EVE NIGHT.
ANOTHER SYSTEM WILL BRING A CHANCE FOR MORE PRECIPITATION LATE NEXT
WEEK. ABOVE NORMAL TEMPERATURES EARLY IN THE WEEK WILL RETURN TO
AROUND NORMAL BY CHRISTMAS.

&&

.NEAR TERM.../TODAY/
ISSUED AT 300 AM EST SAT DEC 20 2014

FORCING FROM AN UPPER WAVE IS CREATING SOME LIGHT PRECIPITATION
ACROSS THE SOUTHERN HALF OF THE FORECAST AREA AT THE MOMENT. THE
MAJORITY OF THIS PRECIPITATION IS NOT REACHING THE GROUND PER
SURFACE OBSERVATIONS. THIS IS DUE TO THE DRY AIR NEAR THE SURFACE.

FORCING WITH THIS UPPER WAVE WILL BE EAST OF THE AREA BY 12Z SO WILL
HAVE NO MENTION OF SNOW THEN. ANOTHER UPPER WAVE WILL MOVE ACROSS
NORTHERN INDIANA DURING THE DAYLIGHT HOURS TODAY...BUT AGAIN
MOISTURE IS LACKING. FORCING IS WEAK AS WELL. THUS WILL KEEP
FORECAST DRY THROUGH THE DAY.

FOCUS THEN SHIFTS TO SKY COVER. SATELLITE SHOWS EXTENSIVE CLOUD
COVER STRETCHING ALL THE WAY BACK TO KANSAS. WITH THE UPPER WAVE
MOVING ACROSS TODAY SEE NO REASON FOR SKIES TO BE ANYTHING OTHER
THAN MOSTLY CLOUDY TO CLOUDY.

WITH THE CLOUDS AROUND WENT COOLER THAN MAV MOS FOR HIGHS...CLOSER
TO THE COOLER MET MOS.

&&

.SHORT TERM.../TONIGHT THROUGH MONDAY NIGHT/
ISSUED AT 300 AM EST SAT DEC 20 2014

FOCUS IS ON SKY COVER AND CHANCES FOR RAIN THROUGH THE PERIOD.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

MODELS TRY AND CLEAR THINGS OUT TONIGHT. CANNOT REALLY SEE THIS
HAPPENING PER RECENT EXPERIENCE AND NOTHING COMING IN TO SCOUR OUT
THE CLOUDS. WILL ONCE AGAIN GO MOSTLY CLOUDY MOST AREAS. WITH THE
CLOUDS WENT CLOSER TO OR EVEN ABOVE THE WARMEST MOS FOR LOWS.

SUNDAY SOME BREAKS IN THE CLOUDS MAY APPEAR ACROSS THE SOUTHERN
TWO-THIRDS OF THE FORECAST AREA AS FLOW BECOMES SOUTHEAST.
CONFIDENCE IS LOW IN THIS THOUGH. SINCE WENT WITH MORE CLOUDS THAN
MODELS SUGGEST...WENT COOLER THAN MAV MOS FOR HIGHS.

DRY CONDITIONS WILL CONTINUE SUNDAY NIGHT AHEAD OF THE APPROACHING
SYSTEM...BUT CLOUDS WILL INCREASE/THICKEN. FORCING INCREASES DURING
THE DAY MONDAY AS ONE UPPER IMPULSE MOVES THROUGH. WENT CHANCE
POPS...HIGHEST IN THE AFTERNOON.

MONDAY NIGHT THE FRONTAL SYSTEM GETS CLOSE TO THE AREA...AND AN
UPPER JET PROVIDES ADDITIONAL FORCING. SOUTHERLY FLOW WILL BRING IN
DECENT MOISTURE...SO WENT LIKELY POPS ALL AREAS.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200600Z TAF ISSUANCE/...

ISSUED AT 1200 AM EST SAT DEC 20 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MFVR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD
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 KIWX 200511
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1211 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...JT
LONG TERM...AGD
AVIATION...STEINWEDEL


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 200511
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1211 AM EST SAT DEC 20 2014

.SYNOPSIS...
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH PRESSURE WILL CONTINUE TO PROVIDE THE REGION WITH DRY
CONDITIONS...LIGHT WINDS...AND MOSTLY CLOUDY SKIES THIS WEEKEND.
HIGHS ARE FORECAST TO REACH THE LOW TO MID 30S TODAY AND THE MID
TO UPPER 30S ON SUNDAY. CHANCES FOR RAIN RETURN MONDAY INTO
TUESDAY AS AN UPPER LEVEL TROUGH DIGS INTO THE PLAINS AND GULF
MOISTURE STREAMS NORTH INTO THE REGION.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1210 AM EST SAT DEC 20 2014

HIGH MVFR TO LOW VFR MVFR CIGS ARE EXPECTED TO PERSIST THROUGH THE
TAF CYCLE AS MOISTURE REMAINS TRAPPED UNDER INVERSION/DIRTY HIGH.
DRY/LIGHT WINDS OTHERWISE WITH LOW LEVEL RIDGE IN PLACE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...JT
LONG TERM...AGD
AVIATION...STEINWEDEL


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 200441
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1141 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 956 PM EST FRI DEC 19 2014

UPPER WAVE MOVING IN FROM MISSOURI IS PRODUCING COOLING CLOUD TOPS
AND WEAK ECHOES UPSTREAM THAT ARE BEGINNING TO MOVE INTO SOUTHWEST
INDIANA BUT NOTHING IS YET REACHING THE GROUND IN INDIANA.
HRRR/RAP/NAM12 ARE ALL SHOWING THIS WAVE PRODUCING SMALL QPF
AMOUNTS ACROSS THE SOUTHERN COUNTIES. GIVEN THE SATELLITE
SIGNATURE WILL GO AHEAD AND ADD CHANCES FOR SNOW ACROSS THE
SOUTHERN COUNTIES WITH UP TO A COUPLE TENTHS OF AN INCH POSSIBLE
STARTING AFTER 6Z AND MOVING OUT OF THE AREA BY 12Z. ALSO
INCREASED CLOUD COVER BASED ON SATELLITE AND WITH THIS IN MIND
INCREASED LOW TEMPERATURES BY A FEW DEGREES AS WELL.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200600Z TAF ISSUANCE/...

ISSUED AT 1200 AM EST SAT DEC 20 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MFVR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
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 200441
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1141 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 956 PM EST FRI DEC 19 2014

UPPER WAVE MOVING IN FROM MISSOURI IS PRODUCING COOLING CLOUD TOPS
AND WEAK ECHOES UPSTREAM THAT ARE BEGINNING TO MOVE INTO SOUTHWEST
INDIANA BUT NOTHING IS YET REACHING THE GROUND IN INDIANA.
HRRR/RAP/NAM12 ARE ALL SHOWING THIS WAVE PRODUCING SMALL QPF
AMOUNTS ACROSS THE SOUTHERN COUNTIES. GIVEN THE SATELLITE
SIGNATURE WILL GO AHEAD AND ADD CHANCES FOR SNOW ACROSS THE
SOUTHERN COUNTIES WITH UP TO A COUPLE TENTHS OF AN INCH POSSIBLE
STARTING AFTER 6Z AND MOVING OUT OF THE AREA BY 12Z. ALSO
INCREASED CLOUD COVER BASED ON SATELLITE AND WITH THIS IN MIND
INCREASED LOW TEMPERATURES BY A FEW DEGREES AS WELL.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200600Z TAF ISSUANCE/...

ISSUED AT 1200 AM EST SAT DEC 20 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
GUIDANCE IS STILL HINTING AT SOME LOW END VFR BY THIS
AFTERNOON...HOWEVER BASED ON PERSISTENCE THE LAST 5 DAYS...BELIEVE
THIS IS VERY OPTIMISTIC AND UNREALISTIC...AND EVEN IF THIS DOES
HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND ALL TERMINALS
WILL RETURN TO MFVR BY THE EARLY EVENING.

WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
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 200306
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1006 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 956 PM EST FRI DEC 19 2014

UPPER WAVE MOVING IN FROM MISSOURI IS PRODUCING COOLING CLOUD TOPS
AND WEAK ECHOES UPSTREAM THAT ARE BEGINNING TO MOVE INTO SOUTHWEST
INDIANA BUT NOTHING IS YET REACHING THE GROUND IN INDIANA.
HRRR/RAP/NAM12 ARE ALL SHOWING THIS WAVE PRODUCING SMALL QPF
AMOUNTS ACROSS THE SOUTHERN COUNTIES. GIVEN THE SATELLITE
SIGNATURE WILL GO AHEAD AND ADD CHANCES FOR SNOW ACROSS THE
SOUTHERN COUNTIES WITH UP TO A COUPLE TENTHS OF AN INCH POSSIBLE
STARTING AFTER 6Z AND MOVING OUT OF THE AREA BY 12Z. ALSO
INCREASED CLOUD COVER BASED ON SATELLITE AND WITH THIS IN MIND
INCREASED LOW TEMPERATURES BY A FEW DEGREES AS WELL.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MVFR BY SAT EVENING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
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 200306
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1006 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 956 PM EST FRI DEC 19 2014

UPPER WAVE MOVING IN FROM MISSOURI IS PRODUCING COOLING CLOUD TOPS
AND WEAK ECHOES UPSTREAM THAT ARE BEGINNING TO MOVE INTO SOUTHWEST
INDIANA BUT NOTHING IS YET REACHING THE GROUND IN INDIANA.
HRRR/RAP/NAM12 ARE ALL SHOWING THIS WAVE PRODUCING SMALL QPF
AMOUNTS ACROSS THE SOUTHERN COUNTIES. GIVEN THE SATELLITE
SIGNATURE WILL GO AHEAD AND ADD CHANCES FOR SNOW ACROSS THE
SOUTHERN COUNTIES WITH UP TO A COUPLE TENTHS OF AN INCH POSSIBLE
STARTING AFTER 6Z AND MOVING OUT OF THE AREA BY 12Z. ALSO
INCREASED CLOUD COVER BASED ON SATELLITE AND WITH THIS IN MIND
INCREASED LOW TEMPERATURES BY A FEW DEGREES AS WELL.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MVFR BY SAT EVENING.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...CP
SHORT TERM...JK
LONG TERM....TDUD
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 200233
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
933 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
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 200233
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
933 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
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 200233
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
933 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
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 200233
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
933 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 932 PM EST FRI DEC 19 2014

0230Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

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

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000
FXUS63 KIWX 200025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
725 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 723 PM EST FRI DEC 19 2014

TRAPPED LOW LVL MSTR WITHIN DIRTY RIDGE WILL AGAIN LEAD TO
PERSISTENT MVFR CIGS THROUGH THE PD. W/SFC RIDGING IN PLACE
THROUGH SATURDAY...XPC WINDS WILL CONT TO BE LIGHT AND VARIABLE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
AVIATION...T


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

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







000
FXUS63 KIWX 200025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
725 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 723 PM EST FRI DEC 19 2014

TRAPPED LOW LVL MSTR WITHIN DIRTY RIDGE WILL AGAIN LEAD TO
PERSISTENT MVFR CIGS THROUGH THE PD. W/SFC RIDGING IN PLACE
THROUGH SATURDAY...XPC WINDS WILL CONT TO BE LIGHT AND VARIABLE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
AVIATION...T


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

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







000
FXUS63 KIWX 200025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
725 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 723 PM EST FRI DEC 19 2014

TRAPPED LOW LVL MSTR WITHIN DIRTY RIDGE WILL AGAIN LEAD TO
PERSISTENT MVFR CIGS THROUGH THE PD. W/SFC RIDGING IN PLACE
THROUGH SATURDAY...XPC WINDS WILL CONT TO BE LIGHT AND VARIABLE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
AVIATION...T


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

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







000
FXUS63 KIWX 200025
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
725 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 723 PM EST FRI DEC 19 2014

TRAPPED LOW LVL MSTR WITHIN DIRTY RIDGE WILL AGAIN LEAD TO
PERSISTENT MVFR CIGS THROUGH THE PD. W/SFC RIDGING IN PLACE
THROUGH SATURDAY...XPC WINDS WILL CONT TO BE LIGHT AND VARIABLE.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
AVIATION...T


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

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000
FXUS63 KIND 192343
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
643 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 640 PM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
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 192343
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
643 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.

&&

.AVIATION /DISCUSSION FOR THE 200000Z TAF ISSUANCE/...

ISSUED AT 640 PM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.

WINDS WILL BE LIGHT AND VARIABLE. GUIDANCE IS HINTING AT SOME LOW
END VFR BY SAT AFTERNOON...HOWEVER BASED ON LAST 4-5 DAYS...BELIEVE
EVEN IF THIS DOES HAPPEN AT A FEW OF THE SITES IT WILL BE BRIEF AND
ALL TERMINALS WILL RETURN TO MFVR BY SAT EVENING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
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
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000
FXUS63 KIWX 192056
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
356 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM EST FRI DEC 19 2014

NARROW BAND OF CLEARING WORKED SOUTHWARD INTO NRN INDIANA THIS
MORNING... HWVR CONSIDERABLE LOW LEVEL MOISTURE REMAINS TRAPPED
BENEATH THE INVERSION AT DTX/ILN THIS MORNING AND WITH RIDGE OVER
IL/WI MOVG VERY SLOWLY EAST... EXPECT MVFR CIGS TO BE PREDOMINANT
THROUGH THE PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
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 192056
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
356 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 353 PM EST FRI DEC 19 2014

HIGH PRESSURE OVER THE GREAT LAKES WILL MOVE SLOWLY EAST TO THE NEW
ENGLAND COAST BY SUNDAY CONTINUING TO PROVIDE GENERALLY FAIR WEATHER
ACROSS OUR AREA OVER THE WEEKEND. AN UPPER LEVEL TROUGH WILL MOVE
SOUTHEAST FROM THE NORTHERN PLAINS ACROSS OUR AREA SATURDAY...
POSSIBLY CAUSING SOME FLURRIES. LOWS TONIGHT WILL BE IN THE MID 20S
WITH HIGHS SATURDAY IN THE MID 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

SFC RIDGE FROM SE CANADA TO THE SRN PLAINS WILL MOVE SLOWLY EAST
THROUGH THIS PERIOD. ALTHOUGH THERE WAS SOME CLEARING TODAY OVER
NRN PORTIONS OF THE AREA... CONSIDERABLE LOW LEVEL MOISTURE WILL
REMAIN TRAPPED IN WK FLOW BENEATH A SUBSIDENCE INVERSION BASED
AROUND 3KFT WHICH SHOULD PROMOTE LOW CLOUDINESS OVER THE AREA
THROUGH SATURDAY. IN ADDITION... A SHRTWV DROPPING SE THROUGH SD
THIS AFTN IS EXPECTED TO MOVE ACROSS OUR AREA SATURDAY. MID/UPR
LEVEL MOISTURE/LIFT ASSOCIATED WITH THIS SYSTEM MAY BE SUFFICIENT
TO CAUSE SOME FLURRIES IN THE AREA... THOUGH A PERSISTENT 3-5KFT
DRY LAYER ABOVE THE LOW LEVEL INVERSION SUGGESTS MEASURABLE PRECIP
IS UNLIKELY. LITTLE CHANGE EXPECTED FROM RECENT TEMPERATURES WITH
LOWS GENERALLY IN M20S AND HIGHS IN THE M30S... THOUGH WITH
LIGHT/VARIABLE WINDS TONIGHT... LOCALLY COOLER MINS LIKELY IF ANY
AREAS CLEAR OUT FOR A FEW HOURS.

&&

.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 353 PM EST FRI DEC 19 2014

INCONSISTENCIES AMONG THE VARIOUS DETERMINISTIC NWP MEMBERS CONTINUE
WITH RESPECT TO POTENTIAL WINTER STORM DURING THE MIDDLE OF NEXT
WEEK. WILL CONTINUE TO TRY TO NARROW DOWN THE SCOPE OF THE EVENT IN
A MEANINGFUL YET JUDICIOUS WAY. NO IMPACTFUL WEATHER EXPECTED DURING
THE LATTER HALF OF THE WEEKEND SO WILL FOCUS ATTENTION ON POSSIBLE
HOLIDAY STORM NEXT WEEK.

THE LARGE SCALE PICTURE REMAINS UNCHANGED. LATEST WATER VAPOR
IMAGERY SHOWS IMPRESSIVE NORTH PACIFIC JET THAT WILL DRIVE THIS
EVENT. THIS JET STREAK WILL EVENTUALLY CARVE OUT A DEEP LONGWAVE
TROUGH OVER THE CENTRAL CONUS THAT WILL FORCE RAPID CYCLOGENESIS AS
IT ROUNDS THE BASE OF AN INCREASINGLY NEGATIVELY TILTED TROUGH. THE
DIFFICULTIES REVOLVE AROUND THE FACT THAT THE JET ENERGY WILL ARRIVE
IN TWO PIECES. THE LEAD WAVE/SURFACE LOW WILL MOVE INTO THE UPPER
MIDWEST ON MONDAY. THE MAIN JET CORE WILL THEN DIG SOUTHEAST AND
DEVELOP A SECONDARY/STRONGER LOW THAT WILL ABSORB THE NORTHERN WAVE
SOMEWHERE OVER THE OHIO VALLEY/GREAT LAKES. IT IS THE EXACT
TIMING/TRACK OF THIS MAIN JET STREAK THAT WILL DETERMINE SENSIBLE
WEATHER IMPACTS FOR OUR LOCAL AREA AND THIS IS WHAT MODELS CONTINUE
TO STRUGGLE WITH. 12Z GFS INDICATES A QUICKER ARRIVAL THAT FORCES
EARLIER PHASING AND A MORE NORTHWEST TRACK OF THE SURFACE LOW
COMPARED TO THE ECMWF AND GEM. THIS WOULD RESULT IN PRIMARILY A RAIN
EVENT FOR OUR AREA WITH JUST SOME LIGHT SNOW AND GUSTY WINDS LATE
WED/EARLY THURS. 12Z ECMWF AND GEM TRACK THIS LOW FURTHER EAST WITH
BETTER CHANCES FOR ACCUMULATING SNOWFALL. HOWEVER...WITH NO GOOD
SOURCE OF COLD AIR UPSTREAM...WILL TAKE TIME FOR PRECIP TO
CHANGEOVER REGARDLESS. SUCH FINER SCALE DETAILS ARE DIFFICULT TO PIN
DOWN THIS FAR OUT BUT WILL HAVE A LARGE IMPACT ON SNOWFALL
AMOUNTS...TIMING...AND LOCATION.

TO SUMMARIZE...STILL EXPECT A STRONG LOW PRESSURE SYSTEM SOMEWHERE
IN THE GREAT LAKES REGION CHRISTMAS EVE INTO CHRISTMAS DAY BUT
IMPORTANT DETAILS ARE STILL UNCLEAR. ALL OF THE PRECIP LATE MONDAY
THROUGH TUESDAY WILL BE IN THE FORM OF RAIN. CHANGEOVER TO SNOW
EXPECTED SOMETIME WEDNESDAY BUT EXACT TIMING AND AMOUNTS REMAIN
UNCERTAIN. SYSTEM WILL EXIT THE AREA ON THURSDAY. AGAIN...ANYONE
WITH CHRISTMAS EVE TRAVEL PLANS SHOULD STAY TUNED TO THE LATEST
FORECASTS AND BE PREPARED FOR HAZARDOUS CONDITIONS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM EST FRI DEC 19 2014

NARROW BAND OF CLEARING WORKED SOUTHWARD INTO NRN INDIANA THIS
MORNING... HWVR CONSIDERABLE LOW LEVEL MOISTURE REMAINS TRAPPED
BENEATH THE INVERSION AT DTX/ILN THIS MORNING AND WITH RIDGE OVER
IL/WI MOVG VERY SLOWLY EAST... EXPECT MVFR CIGS TO BE PREDOMINANT
THROUGH THE PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
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 192021
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
320 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/2100Z TAF ISSUANCE/...

ISSUED AT 320 AM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...TDUD/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 192021
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
320 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/2100Z TAF ISSUANCE/...

ISSUED AT 320 AM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...TDUD/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 192021
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
320 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/2100Z TAF ISSUANCE/...

ISSUED AT 320 AM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...TDUD/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 192021
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
320 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONSENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/2100Z TAF ISSUANCE/...

ISSUED AT 320 AM EST FRI DEC 19 2014

AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR THE
SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF PERIOD.
WINDS WILL BE LIGHT AND VARIABLE.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....TDUD
AVIATION...TDUD/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 191956
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
256 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONCENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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

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 191956
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
256 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONCENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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

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 191956
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
256 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONCENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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

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 191956
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
256 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.

&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...

ISSUED AT 235 PM EST FRI DEC 19 2014

THE MAIN FOCUS OF THE LONG TERM PERIOD WILL BE A STORM SYSTEM
PROGGED TO HIT CENTRAL INDIANA OVER THE CHRISTMAS HOLIDAY.

MODELS ARE IN DECENT CONCENSUS FOR THAT FAR OUT IN THE FORECAST.
EURO AND GFS BOTH INDICATE A RATHER STRONG CUT-OFF LOW CENTERED
OVER THE NORTHERN PLAINS ON MONDAY NIGHT WITH SIGNIFICANT RIDGING
OVER THE WEST COAST. PRECIP WILL BE IN THE FORECAST FOR THE
DURATION OF LONG TERM PERIOD...BUT IN THE FORM OF RAIN FROM MONDAY
NIGHT THROUGH TUESDAY NIGHT AS WARM ADVECTION AT THE SURFACE MOVES
IN AHEAD OF THE UPPER SYSTEM. AS ASSOCIATED COLD FRONT MOVES IN ON
TUESDAY NIGHT...RAIN WILL SLOWLY TRANSITION TO A RAIN/SNOW MIX.
PRECIP CHANCES ARE CURRENTLY IN THE 50 TO 60 PERCENT RANGE...BUT
ANTICIPATE THESE CHANCES TO INCREASE IN COMING DAYS. AT THIS
TIME...BEST VORTICITY MAXIMA SHOULD MOVE THROUGH THE FORECAST AREA
ON TUESDAY NIGHT/WEDNESDAY MORNING. AT THAT POINT...THE COLDER AIR
WILL START FILTERING INTO CENTRAL INDIANA...BUT SINCE BEST
DYNAMICS WILL ALREADY BE TO THE EAST OF FORECAST AREA...DO NOT
EXPECT HIGH SNOW ACCUMULATIONS AT THIS TIME. NONETHELESS...GUSTY
WEST WINDS COULD STILL RESULT IN BLOWING SNOW AND TRAVEL HAZARDS
ON WEDNESDAY AND THURSDAY.

THOSE WITH TRAVEL PLANS DURING THIS TIME PERIOD ARE ENCOURAGED TO
STAY TUNED IN THE COMING DAYS.


&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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

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 191904
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
204 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.


&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014


THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....RYAN
AVIATION...TDUD

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 191904
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
204 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.


&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014


THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....RYAN
AVIATION...TDUD

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 191904
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
204 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.


&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014


THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....RYAN
AVIATION...TDUD

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 191904
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
204 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 205 PM EST FRI DEC 19 2014

A HIGH PRESSURE SYSTEM WILL DOMINATE INDIANA WEATHER INTO SUNDAY AS
ITS CENTER SHIFTS FROM THE MID MISSISSIPPI VALLEY TO NEW ENGLAND.

FROM MONDAY INTO THURSDAY THE MOST IMPORTANT INFLUENCE ON HOOSIER
WEATHER IS GOING TO BE A LOW PRESSURE SYSTEM. THIS SYSTEM IS
FORECAST TO START DEVELOPING OVER THE PLAINS LATE IN THE WEEKEND. IT
IS EXPECTED TO HEAD EAST...GAINING STRENGTH AS IT DOES.

BY TUESDAY MORNING LOW PRESSURE WILL HAVE ARRIVED IN THE UPPER
MISSISSIPPI VALLEY. BY WEDNESDAY IT IS EXPECTED TO BE
VERY...VERY...STRONG AND CENTERED OVER SOUTHERN ONTARIO. LATE
CHRISTMAS DAY ITS INFLUENCE ON INDIANA WILL WEAKEN AS IT HEADS INTO
QUEBEC.

FRIDAY OUR WEATHER IS PREDICTED COME UNDER THE INFLUENCE OF ANOTHER
LOW PRESSURE SYSTEM COMING FROM THE PLAINS.


&&

.NEAR TERM /TONIGHT AND SATURDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014


THE MAIN ISSUE IS CLOUDINESS AND ITS AFFECT ON TEMPERATURES.

CLEARING DEVELOPED OVER MUCH OF ILLINOIS AND SOUTHWEST INDIANA
TODAY. HOWEVER LATEST SATELLITE PICTURES SHOW STRATUS MOVING TOWARD
THE CLEAR AREA FROM THE NORTHEAST...AND CLOUDS WITH A SHORT WAVE
APPROACHING FROM THE SOUTHWEST. TONIGHT SHOULD BE CLOUDY.

THE MODELS AGREE BY LATE SATURDAY THE SHORT WAVE IS GOING TO BE TO
OUR EAST AND THE ATMOSPHERIC COLUMN WILL BE DRYING. THEY ALSO AGREE
WE WILL BE UNDER AN INVERSION ON THE EAST SIDE OF A RIDGE WITH 925
MILLIBAR RELATIVE HUMIDITIES 70 PERCENT OR HIGHER.

SUCH A PATTERN FAVORS STRATUS. SATURDAY IS GOING TO BE ANOTHER
MOSTLY CLOUDY DAY. THE SOUTHWEST MIGHT GET A LITTLE SUN IN THE
AFTERNOON.

CLOUDS ARE GOING TO DAMPEN DIURNAL TEMPERATURES CHANGES. MAV AND MET
MINIMUMS ARE CLOSE OVERNIGHT. THEY LOOK OK CONSIDERING WHAT WE HAVE
NOW. THERE HAS BEEN A STRONG WARM BIAS IN SIMILAR SITUATIONS WITH
DAYTIME TEMPERATURES LATELY. THE COOLER MET TEMPERATURES ARE
PREFERRED SATURDAY. POSSIBLY EVEN THEY WILL BE TOO WARM.

&&

.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...

ISSUED AT 205 PM EST FRI DEC 19 2014

ALL THE MODELS AGREE IT WILL BE DRY THROUGH SUNDAY NIGHT WITH A
CHANCE OF RAIN MONDAY AS A WARM FRONT DEVELOPS OVER THE AREA. CLOUDS
AND TEMPERATURES ARE THE MAIN FORECAST ISSUES.

SATURDAY NIGHT WE SHOULD MOVE TO THE WEST SIDE OF A WEAK SURFACE
RIDGE. THIS WILL GIVE A CHANCE TO SCOUR OUT THE LOW LEVEL MOISTURE
THAT HAS BEEN PERSISTENT RECENTLY. HOWEVER AS THAT HAPPENS WARM
ADVECTION ALOFT SHOULD CAUSE MID LEVEL CLOUDINESS. WE CAN EXPECT
CLOUDY WEATHER TO CONTINUE.

THE RESULT IS GOING TO BE DAMPENED TEMPERATURE CHANGES...ALTHOUGH
NOT QUITE TO EXTENT AS EARLIER IN THE WEEK SINCE THE CLOUDS SHOULD
BE MID LEVEL AS OPPOSED TO LOW LEVEL. GUIDANCE TEMPERATES MAY BE
OK SATURDAY NIGHT CONSIDERING WHAT DAYTIME READINGS WILL BE. AFTER
THAT THE COOLER MET LOOKS BETTER FOR SUNDAY AND THE WARMER MAV
FOR SUNDAY NIGHT.

ON MONDAY STRONG WARM ADVECTION WILL COUNTERACT THICKENING CLOUDS AND
POSSIBLY RAIN AS A WARM FRONT FORMS OVER US. TEMPERATURES COULD
SURGE INTO THE 50S OR STAY IN THE 40S DEPENDING ON HOW THINGS COME
TOGETHER. A CONSENSUS BETWEEN THE MEX AND THE EUROPEAN GUIDANCE
WILL BE USED.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....RYAN
AVIATION...TDUD

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 191725
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1225 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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 191725
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1225 PM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1800Z TAF ISSUANCE/...

ISSUED AT 1156 AM EST FRI DEC 19 2014

A BRIEF PERIOD OF CLEARING OVER KHUF AND KBMG WILL COME TO AN END
WITHIN THE NEXT FEW HOURS AS PERSISTENT STRATUS FILTERS BACK INTO
THE TAF SITES. AN INVERSION WILL CONTINUE TO TRAP MOISTURE NEAR
THE SURFACE...RESULTING IN MVFR CONDITIONS FOR DURATION OF TAF
PERIOD.  WINDS WILL BE LIGHT AND NORTHERLY.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...TDUD

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIWX 191720
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1220 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM EST FRI DEC 19 2014

NARROW BAND OF CLEARING WORKED SOUTHWARD INTO NRN INDIANA THIS
MORNING... HWVR CONSIDERABLE LOW LEVEL MOISTURE REMAINS TRAPPED
BENEATH THE INVERSION AT DTX/ILN THIS MORNING AND WITH RIDGE OVER
IL/WI MOVG VERY SLOWLY EAST... EXPECT MVFR CIGS TO BE PREDOMINANT
THROUGH THE PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...JT


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

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






000
FXUS63 KIWX 191720
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1220 PM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1205 PM EST FRI DEC 19 2014

NARROW BAND OF CLEARING WORKED SOUTHWARD INTO NRN INDIANA THIS
MORNING... HWVR CONSIDERABLE LOW LEVEL MOISTURE REMAINS TRAPPED
BENEATH THE INVERSION AT DTX/ILN THIS MORNING AND WITH RIDGE OVER
IL/WI MOVG VERY SLOWLY EAST... EXPECT MVFR CIGS TO BE PREDOMINANT
THROUGH THE PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...JT


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

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







000
FXUS63 KIWX 191549
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1049 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 191549
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1049 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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

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







000
FXUS63 KIWX 191549
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1049 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 191549
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1049 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1047 AM EST FRI DEC 19 2014

A RIDGE OF HIGH PRESSURE WILL BRING DRY CONDITIONS THIS AFTERNOON
AND GENERALLY MOSTLY CLOUDY SKIES. TEMPERATURES WILL BE NEAR
NORMAL.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...FRAZIER
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 191422
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1500Z TAF UPDATE/...

ISSUED AT 919 AM EST FRI DEC 19 2014

UPDATE...
NO CHANGES.

PREVIOUS DISCUSSION...
MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 191422
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1500Z TAF UPDATE/...

ISSUED AT 919 AM EST FRI DEC 19 2014

UPDATE...
NO CHANGES.

PREVIOUS DISCUSSION...
MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 191422
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1500Z TAF UPDATE/...

ISSUED AT 919 AM EST FRI DEC 19 2014

UPDATE...
NO CHANGES.

PREVIOUS DISCUSSION...
MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 191422
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR THE 19/1500Z TAF UPDATE/...

ISSUED AT 919 AM EST FRI DEC 19 2014

UPDATE...
NO CHANGES.

PREVIOUS DISCUSSION...
MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN/TDUD

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 191135
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
635 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 191200Z TAF ISSUANCE/...
ISSUED AT 537 AM EST FRI DEC 19 2014

MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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 191135
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
635 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 635 AM EST FRI DEC 19 2014

CLOUD DECK IS MOVING SOUTH FASTER THAN PREVIOUSLY THOUGHT...SO
INCREASED CLOUD COVER AS NEEDED THIS MORNING.

PREVIOUS DISCUSSION FOLLOWS...
HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 191200Z TAF ISSUANCE/...
ISSUED AT 537 AM EST FRI DEC 19 2014

MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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 191037
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
537 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 191200Z TAF ISSUANCE/...
ISSUED AT 537 AM EST FRI DEC 19 2014

MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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

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000
FXUS63 KIND 191037
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
537 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 191200Z TAF ISSUANCE/...
ISSUED AT 537 AM EST FRI DEC 19 2014

MVFR CEILINGS POSSIBLE THROUGHOUT THE FORECAST PERIOD.

POCKET OF CLEAR SKIES EXTENDING SOUTHEAST FROM EXTREME EASTERN
IOWA INTO THE SOUTHERN HALF OF INDIANA EARLY THIS MORNING. STRATUS
LINGERS EITHER SIDE OF THIS AREA ACROSS THE REGION...AND REMAINS
THE PRIMARY CHALLENGE FOR THE FORECAST TODAY.

STRATUS ENCOMPASSING NORTHERN INDIANA HAS BEEN SLOWLY EXPANDING
SOUTH OVER THE LAST FEW HOURS...AND RAP/NAM 925MB ANALYSIS
SUGGESTS THIS TREND SHOULD CONTINUE THROUGH THE MORNING AIDED BY
WEAK NORTHEAST FLOW WITHIN THE BOUNDARY LAYER. IN ADDITION...MODEL
SOUNDINGS SHOW CONVECTIVE TEMPS ONLY AROUND 30F BY MIDDAY WITH
LIKELIHOOD THAT CU DEVELOPS AND COALESCES WITH THE STRATUS DECK.
WHILE THERE IS LIKELY TO BE PERIODS WITH SCATTERED CLOUD COVERAGE
THIS MORNING...OVERALL TREND SUPPORTS MORE OF A MOSTLY CLOUDY SKY
TODAY. BASES WILL LIKELY VARY ANYWHERE BETWEEN 2000-3500FT THROUGH
THE AFTERNOON.

HIGH PRESSURE REMAINS OVER THE AREA TONIGHT AS AN UPPER LEVEL WAVE
PASSES TO THE SOUTH. MODEL SOUNDINGS INDICATE CLOUDS ARE LIKELY TO
BE STUBBORN OVERNIGHT...WITH MOISTURE BECOMING TRAPPED ONCE AGAIN
UNDER AN INVERSION. WILL MAINTAIN MVFR CEILINGS AS A RESULT ALL
NIGHT. WINDS WILL BE LIGHT AND VARIABLE THROUGHOUT THE FORECAST
PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...RYAN

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

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000
FXUS63 KIWX 191030
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
530 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH MAY BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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000
FXUS63 KIWX 191030
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
530 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH MAY BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING (MAINLY
ALONG/NORTH OF US 30). THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN
WILL HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS
THE REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY
REMAINING TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 530 AM EST FRI DEC 19 2014

MVFR CIGS AND LIGHT WINDS THE HIGHLIGHT THIS PERIOD UNDER
LINGERING INVERSION/HIGH PRESSURE. WEAK SFC TROUGH MAY TOUCH OFF
SOME SPOTTY SHSN/FZDZ AND FUEL ALT CEILINGS THIS MORNING. DRY
CONDITIONS OTHERWISE WITH POTENTIAL FOR BRIEF IMPROVEMENT TO VFR
POSSIBLE MIDDAY/AFTERNOON.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 190900
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
400 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH WILL BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING MAINLY
ALONG/NORTH OF US 30. THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN WILL
HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS THE
REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY REMAINING
TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM EST FRI DEC 19 2014

WEAK SFC TROUGH NOW ACROSS FAR SOUTHERN LOWER MI WILL DROP INTO
NORTHERN IN THIS MORNING. THIS FEATURE AND SOME LAKE ENHANCEMENT
WILL LIKELY BRING A FEW SNOW SHOWERS AND POTENTIALLY PATCHY
FREEZING DRIZZLE TO MAINLY KSBN EARLY THIS MORNING. MAINLY
DRY/CLOUDY THEREAFTER AS TROUGH BECOMES INCREASINGLY DIFFUSE WITH
HIGH PRESSURE BECOMING BETTER ESTABLISHED. OTHERWISE...MVFR CIGS
EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD (MAY SEE BRIEF
IMPROVEMENT TO LOW VFR TOWARD MIDDAY/AFTERNOON) GIVEN RESIDUAL
MOISTURE UNDER LINGERING LOW LEVEL THERMAL INVERSION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 190900
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
400 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH WILL BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 355 AM EST FRI DEC 19 2014

WEAK SFC-850 MB TROUGH ACROSS SOUTHERN LOWER MI WILL BECOME
INCREASINGLY DIFFUSE INTO NRN IN/OH TODAY. THERE MAY BE JUST ENOUGH
LAKE ENHANCEMENT AND LOW LEVEL CONVERGENCE/MOISTURE TO FOCUS A FEW
FLURRIES OR PATCHY FREEZING DRIZZLE THROUGH MID MORNING MAINLY
ALONG/NORTH OF US 30. THIS COULD LEAD TO A FEW SLICK SPOTS EARLY
THIS MORNING. DRY/SEASONABLE OTHERWISE AS LOW AMPLITUDE SHORTWAVE
RIDGING OVERSPREADS IN ADVANCE OF A DISJOINTED HIGH PLAINS UPPER
TROUGH AXIS. THIS AND HIGH STATIC STABILITY THROUGH THE COLUMN WILL
HELP SFC HIGH PRESSURE BECOME MORE FIRMLY ESTABLISHED ACROSS THE
REGION INTO TONIGHT...WITH A BKN/OVC LOW CLOUD DECK LIKELY REMAINING
TRAPPED BENEATH A STUBBORN INVERSION FOR MOST LOCATIONS.

&&

.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 355 AM EST FRI DEC 19 2014

NOT A LOT OF CHANGE IN THINKING HERE WITH RESPECT TO WINTER STORM
NEXT WEEK...BUT AS EXPECTED MODELS CONTINUE TO JUMP AROUND WITH
POTENTIAL SOLUTIONS. CONFIDENCE REMAINS HIGH ON A STRONG WINTER
STORM IN THE MIDWEST AND GREAT LAKES REGION BUT THE IMPORTANT
DETAILS ON STORM TRACK...PCPN TYPE AND SNOW AMOUNTS REMAIN QUITE
UNCERTAIN.

NORTHERN HEMISPHERIC WATER VAPOR LOOP FROM THE PAST WEEK TELLS THE
STORY OF DEVELOPING PATTERN CHANGE AND ORIGIN OF ENERGY FOR UPCOMING
WINTER STORM. POWERFUL 160-180KT JET ENERGY CURRENTLY OVER NORTHERN
PACIFIC HANDLED FAIRLY WELL BY MODEL INITIATIONS PER GOES HIGH
DENSITY WIND PLOTS. VAPOR LOOP SHOWS IMPRESSIVE MOISTURE PLUME
STRETCHING BACK TO EAST ASIA AND THE SOUTH PACIFIC. THIS PLUME HAS
BEEN ENERGIZED BY RECURVING TROPICAL DISTURBANCES FROM THE SOUTH
PACIFIC AS WELL AS THE INDIAN OCEAN. THIS HAS HELPED STRENGTHEN
NORTHERN PACIFIC JET WITH ENERGY SET TO RIDE INTO WESTERN CONUS THIS
WEEKEND AND INTO NORTHERN PLAINS EARLY NEXT WEEK. BUILDING RIDGES IN
BOTH THE WESTERN ATLANTIC AND ESPECIALLY EASTERN PACIFIC WILL HELP
THIS JET ENERGY FORM A CLOSED LOW SOMEWHERE OVER THE MIDWEST TO
GREAT LAKES REGION. THIS IS WHERE THE UNCERTAINTY IN DETAILS LIES AS
MEDIUM RANGE MODELS CONTINUE TO DIVERGE ON HOW AND WHERE THIS LOW
WILL FORM AND EVOLVE.

THE GENERAL SYNOPTIC IDEA REMAINS SIMILAR AMONG THE MODELS WITH MID
LEVEL LOW FORMING TO OUR WEST ACROSS THE PLAINS STATES SUNDAY INTO
MONDAY. SOUTHERLY LOW LEVEL JET WILL INCREASE AHEAD OF THIS LOW
MONDAY INTO TUESDAY ALLOWING DEEP MOISTURE TRANSPORT INTO OUR AREA.
THERMAL PROFILES WARM ENOUGH FOR MAINLY RAIN THROUGH TUESDAY. PWATS
AROUND THREE QUARTERS OF AN INCH BEING SHOWN BY MEDIUM RANGE MODELS
WHICH IS CLOSE TO BEING 2 STANDARD DEVIATIONS ABOVE NORMAL. THUS
SOME CONCERN GROWING WITH THIS LATEST MODEL RUN OF MODERATE TO HEAVY
RAINFALL RELATIVE TO MID DECEMBER. FORTUNATELY NO SNOW PACK TO WORRY
ABOUT AND RIVERS RUNNING NEAR NORMAL.

AS STORM DEEPENS AND TAKES ON A NEGATIVE TILT TUESDAY...SECONDARY
ENERGY IN BASE OF ELONGATED TROUGH BECOMES THE PROBLEMATIC FEATURE
FOR MODELS AND THE DETERMINING FACTOR FOR HOW MUCH SNOW WE WILL SEE
TUE NIGHT INTO WED. LATEST 00Z ECMWF AND GEM NOW REVERTING BACK TO
PREVIOUS SOLUTIONS WITH SECONDARY LOW FORMING IN MID MS VALLEY AND
MOVING NORTHEAST THROUGH WESTERN OH AS A PANHANDLE HOOK TYPE SCENARIO.
BOTH OF THESE MODELS HAVE A SUB 990MB LOW NOW OVER WESTERN OH BY 12Z
WED WITH POTENTIAL FOR DECENT SNOWFALL OVER PARTS OF THE CWA.
OPERATIONAL GFS IS SIMILAR BUT MUCH WEAKER WITH THIS SFC LOW.
MEANWHILE...PARALLEL GFS SHOWS A SIMILAR SOLUTION TO ECMWF/GEM BUT
TAKES THE LOW NORTH ALONG THE IN/IL STATE LINE WITH A 979MB SFC LOW
OVER LAKE MICHIGAN BY 12Z WED. OBVIOUSLY THIS WOULD GIVE US MUCH
LESS SNOWFALL. CONFIDENCE REMAINS LOW IN DETAILS FOR CHANGEOVER TO
SNOWFALL AND POTENTIAL AMOUNTS GIVEN THIS PLETHORA OF SOLUTIONS AND
MAIN PLAYERS STILL OVER THE DATA SPARSE NORTH PACIFIC. PAST
EXPERIENCE HAS SHOWN THAT THESE WINTER STORMS WITH A STRONG NEGATIVE
TILT TEND TO FAVOR A MORE WESTWARD SOLUTION.

WILL MAINTAIN CONSISTENCY WITH PREVIOUS FORECAST AND SURROUNDING
SITES USING SUPERBLEND INIT BUT GIVEN DECENT AGREEMENT ON
PRECIPITATION ACROSS THE AREA MONDAY NIGHT THROUGH TUESDAY NIGHT DID
NUDGE ENTIRE AREA INTO LIKELY POP CATEGORY FOR THESE PERIODS. ALSO
INCREASED SKY COVER AND WINDS. AS FOR PCPN TYPE...KEPT IT ALL RAIN
THROUGH TUESDAY AND LEFT TUE NIGHT AS RAIN OR SNOW GIVEN
UNCERTAINTY. BY WED THE STORM SHOULD BE OCCLUDING AND MOST LIKELY
NORTH OF US SO COLD AIR SHOULD BE WRAPPED AROUND AND IN PLACE GIVEN
ALL CURRENT SOLUTIONS. THUS HAVE ALL SNOW FOR WED AND WED NIGHT.
LAKE RESPONSE THEN LIKELY INTO CHRISTMAS DAY WITH WINDY CONDITIONS
OVER ENTIRE AREA. STRONG WINDS AND SHORT WNW FETCH OVER THE LAKE MAY
ACTUALLY BE A DETRIMENT TO LAKE EFFECT BUT STILL WORTHY OF CHANCE
POPS IN FAVORED NW AREAS.

NOT TO FORGET THE EARLY PART OF THE LONG TERM PERIOD BUT WEATHER
WILL BE BENIGN WITH A FEW SUBTLE SHORT WAVES. WEAK PV ANOMALY AND
SHORT WAVE ON SATURDAY MAY SQUEEZE OUT A FEW FLURRIES BUT MOISTURE
LACKING FOR ACCUMULATIONS. WARMING TREND INTO NEXT WEEK AHEAD OF
DEVELOPING STORM.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM EST FRI DEC 19 2014

WEAK SFC TROUGH NOW ACROSS FAR SOUTHERN LOWER MI WILL DROP INTO
NORTHERN IN THIS MORNING. THIS FEATURE AND SOME LAKE ENHANCEMENT
WILL LIKELY BRING A FEW SNOW SHOWERS AND POTENTIALLY PATCHY
FREEZING DRIZZLE TO MAINLY KSBN EARLY THIS MORNING. MAINLY
DRY/CLOUDY THEREAFTER AS TROUGH BECOMES INCREASINGLY DIFFUSE WITH
HIGH PRESSURE BECOMING BETTER ESTABLISHED. OTHERWISE...MVFR CIGS
EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD (MAY SEE BRIEF
IMPROVEMENT TO LOW VFR TOWARD MIDDAY/AFTERNOON) GIVEN RESIDUAL
MOISTURE UNDER LINGERING LOW LEVEL THERMAL INVERSION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...STEINWEDEL
LONG TERM...LASHLEY
AVIATION...STEINWEDEL


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 190833
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
333 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 190900Z TAF UPDATE/...
ISSUED AT 333 AM EST FRI DEC 19 2014

POCKETS OF CLEARING CONTINUE ACROSS THE AREA EARLY THIS MORNING AS
HIGH PRESSURE BUILDS IN. STILL ANTICIPATE PERIODS WITH
BROKEN/OVERCAST MVFR FOR THE NEXT FEW HOURS AND WILL CONTINUE WITH
A TEMPO GROUP. TWEAKED WIND DIRECTION BASED ON CURRENT
OBS...OTHERWISE NO ADDITIONAL CHANGES.

06Z DISCUSSION FOLLOWS.

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...CP/RYAN

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 190833
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
333 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 190900Z TAF UPDATE/...
ISSUED AT 333 AM EST FRI DEC 19 2014

POCKETS OF CLEARING CONTINUE ACROSS THE AREA EARLY THIS MORNING AS
HIGH PRESSURE BUILDS IN. STILL ANTICIPATE PERIODS WITH
BROKEN/OVERCAST MVFR FOR THE NEXT FEW HOURS AND WILL CONTINUE WITH
A TEMPO GROUP. TWEAKED WIND DIRECTION BASED ON CURRENT
OBS...OTHERWISE NO ADDITIONAL CHANGES.

06Z DISCUSSION FOLLOWS.

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...CP/RYAN

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 190833
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
333 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 190900Z TAF UPDATE/...
ISSUED AT 333 AM EST FRI DEC 19 2014

POCKETS OF CLEARING CONTINUE ACROSS THE AREA EARLY THIS MORNING AS
HIGH PRESSURE BUILDS IN. STILL ANTICIPATE PERIODS WITH
BROKEN/OVERCAST MVFR FOR THE NEXT FEW HOURS AND WILL CONTINUE WITH
A TEMPO GROUP. TWEAKED WIND DIRECTION BASED ON CURRENT
OBS...OTHERWISE NO ADDITIONAL CHANGES.

06Z DISCUSSION FOLLOWS.

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...CP/RYAN

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 190833
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
333 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /MONDAY THROUGH THURSDAY/...
ISSUED AT 333 AM EST FRI DEC 19 2014

A MUCH MORE ACTIVE AND UNSETTLED WEATHER PATTERN SETTING UP FOR
THE HOLIDAY WEEK...HIGHLIGHTED BY A POTENTIAL LARGE STORM SET TO
IMPACT THE GREAT LAKES AND OHIO VALLEY TUESDAY THROUGH CHRISTMAS.
LOTS TO TALK ABOUT THIS MORNING.

STRONG RIDGING ALOFT SET TO DEVELOP OFF THE PACIFIC COAST AT THE
BEGINNING OF THE EXTENDED...AND THIS WILL PROMPT FALLING HEIGHTS
DOWNSTREAM EAST OF THE ROCKIES AS THE UPPER LEVEL FLOW AMPLIFIES.
QUITE A BIT OF ENERGY COURTESY OF A VERY STRONG UPPER LEVEL JET
PLOWING INTO THE PACIFIC NORTHWEST SET TO DIVE INTO THE EXPANDING
TROUGH AND LEAD TO PHASING WITH SOUTHERN STREAM JET ENERGY. AT THE
SURFACE...LOW PRESSURE SET TO TRACK OUT OF THE NORTHERN PLAINS ON
MONDAY WITH A TRAILING COLD FRONT. MOISTURE WILL BE DRAWN NORTH
INTO THE REGION AS THE FRONT AND SURFACE WAVE APPROACH...WITH RAIN
BECOMING LIKELY BY MONDAY NIGHT.

RAIN WILL CONTINUE ON TUESDAY AS THE AFOREMENTIONED SURFACE WAVE
TRACKS INTO THE GREAT LAKES. A SECOND AREA OF LOW PRESSURE SET TO
ORGANIZE OVER THE NORTHWEST GULF/LOWER MISSISSIPPI VALLEY DURING
THE DAY TUESDAY AS THE SUBTROPICAL JET ENERGY LINKS UP WITH THE
NORTHERN STREAM JET. THE UPPER TROUGH WILL QUICKLY GAIN A NEGATIVE
TILT WITH RAPID CYCLOGENESIS COMMENCING TUESDAY NIGHT INTO EARLY
WEDNESDAY.

INDIVIDUAL MODEL RUNS THIS MORNING DIFFER WITH REGARDS TO TIMING
AND LOCATION OF THE PHASING SURFACE WAVE...BUT THE KEY TAKEAWAY IS
THAT MODEL CONSENSUS INCLUDING BULK OF THE ENSEMBLE RUNS ALL SHOW
THE DEEPENING SYSTEM OVER THE EASTERN PART OF THE COUNTRY.
CONFIDENCE CONTINUES TO GROW IN A HIGH IMPACT SYSTEM FOR THE
REGION FROM LATE TUESDAY INTO EARLY THURSDAY...BUT THE DETAILS ARE
YET TO BE IRONED OUT AND LIKELY WILL NOT BE FOR ANOTHER FEW DAYS
UNTIL THE INTENSE UPPER JET ENERGY APPROACHING THE PACIFIC
NORTHWEST IS PROPERLY SAMPLED BY THE UPPER AIR NETWORK. AT THIS
POINT...HAVE LEANED IN THE DIRECTION OF THE GLOBAL MODELS WHICH
FAVOR A FASTER PHASING...BUT ALL POSSIBILITIES REMAIN OPEN AT THIS
EARLY STAGE UNTIL GREATER MODEL CONSENSUS CAN BE REACHED.

WITH ALL OF THIS BEING SAID...ANTICIPATE RAIN MIXING WITH THEN
CHANGING TO SNOW TUESDAY NIGHT INTO WEDNESDAY. FAR TOO EARLY TO
TALK POTENTIAL ACCUMULATIONS WEDNESDAY THROUGH EARLY THURSDAY...BUT
THESE LOOK RELATIVELY LIGHT AT THIS POINT. WIND IS LIKELY TO BE A
MORE SIGNIFICANT FACTOR CONSIDERING THE PROGGED INTENSITY OF THE
LOW TO SUB-980MB LEVELS AND POSSIBLY LOWER BY EARLY THURSDAY. EVEN
IF SNOW AMOUNTS ARE LIGHT...WIND DRIVEN SNOW SHOWERS COULD CREATE
TRAVEL DIFFICULTIES AT THE WORST POSSIBLE TIME...CHRISTMAS EVE
INTO EARLY CHRISTMAS MORNING. THOSE WITH TRAVEL PLANS DURING THIS
TIME PERIOD ARE ENCOURAGED TO STAY TUNED IN THE COMING DAYS. AND THIS
MAY JUST BE THE START...AS AN ACTIVE PATTERN LIKELY PERSISTS BEYOND
THE 7 DAY INTO NEXT WEEKEND.

&&

.AVIATION /DISCUSSION FOR 190900Z TAF UPDATE/...
ISSUED AT 333 AM EST FRI DEC 19 2014

POCKETS OF CLEARING CONTINUE ACROSS THE AREA EARLY THIS MORNING AS
HIGH PRESSURE BUILDS IN. STILL ANTICIPATE PERIODS WITH
BROKEN/OVERCAST MVFR FOR THE NEXT FEW HOURS AND WILL CONTINUE WITH
A TEMPO GROUP. TWEAKED WIND DIRECTION BASED ON CURRENT
OBS...OTHERWISE NO ADDITIONAL CHANGES.

06Z DISCUSSION FOLLOWS.

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....RYAN
AVIATION...CP/RYAN

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000
FXUS63 KIND 190752
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
252 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD/JP
AVIATION...CP

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000
FXUS63 KIND 190752
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
252 AM EST FRI DEC 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL KEEP CENTRAL INDIANA DRY THROUGH THE
WEEKEND...EVEN THOUGH UPPER SYSTEMS WILL MOVE ACROSS THE AREA. A
LARGE LOW PRESSURE SYSTEM WILL BRING CHANCES FOR PRECIPITATION
MONDAY THROUGH CHRISTMAS EVE. TEMPERATURES WILL WARM TO ABOVE
AVERAGE BY EARLY NEXT WEEK THEN COOL AGAIN BY MID WEEK.

&&

.NEAR TERM.../TODAY/
ISSUED AT 252 AM EST FRI DEC 19 2014

HIGH PRESSURE WILL REMAIN ACROSS THE AREA TODAY...KEEPING THINGS DRY.

LARGE HOLES HAVE DEVELOPED IN THE CLOUD COVER THANKS TO SOME OF THE
DRIER AIR MOVING IN WITH THE HIGH. THE HOLES ROUGHLY FOLLOW THE
SURFACE RIDGE AXIS. MODELS SHOW SOME OF THIS DRY AIR PERSISTING
THROUGH THE DAY...BUT SOME OF THE HOLES ARE ALREADY CLOSING IN IOWA
AT THE MOMENT.

THUS SKY COVER FORECAST IS TOUGH TODAY AND CONFIDENCE IS LOW. KEPT
SKIES MOSTLY CLOUDY ACROSS THE NORTHEAST FORECAST AREA TODAY CLOSER
TO SOME COOLER AIR ALOFT WHICH WILL HELP KEEP THE CLOUDS THERE
INTACT. ACROSS THE SOUTHWEST HALF ALLOWED FOR SOME PARTLY CLOUDY
SKIES TODAY BASED ON LATEST TRENDS AND MODEL MOISTURE FORECASTS.

WHERE SKIES HAVE CLEARED...TEMPERATURES HAVE DIPPED TO AROUND 20
EARLY THIS MORNING. THE COLD START IN THESE AREAS...ALONG WITH
CLOUDS INHIBITING TEMPERATURE RISES ELSEWHERE...SHOULD LEAD TO HIGHS
A LITTLE COLDER THAN MAV MOS WOULD SUGGEST MOST AREAS.

&&

.SHORT TERM.../TONIGHT THROUGH SUNDAY NIGHT/
ISSUED AT 252 AM EST FRI DEC 19 2014

FOCUS IS ON ANY THREAT FOR PRECIPITATION AS WELL AS ON SKY COVER.
MODELS ARE CLOSE ENOUGH THAT A BLEND WAS USED.

AN UPPER TROUGH WILL MOVE ACROSS THE AREA LATER TONIGHT AND
SATURDAY. BULK OF FORCING AND MOISTURE WILL BE CONFINED WELL SOUTH
OF CENTRAL INDIANA. HIGH PRESSURE WILL REMAIN IN CONTROL AT THE
SURFACE.

THUS JUST EXPECT A THICKER CLOUD COVER TO MOVE IN ONCE AGAIN DURING
THIS PERIOD BUT NO MEASURABLE PRECIPITATION. CANNOT ABSOLUTELY RULE
OUT SOME FLURRIES SATURDAY...BUT AT THE MOMENT FEEL THAT THE ODDS
ARE TOO LOW TO MENTION.

SUNDAY AND SUNDAY NIGHT CENTRAL INDIANA WILL REMAIN IN BETWEEN
SYSTEMS TO THE NORTHWEST AND SOUTHEAST. SOME MODELS TRY TO BRING
SOME PRECIPITATION INTO THE FAR SOUTHEAST SUNDAY NIGHT...BUT DO NOT
FEEL THAT ODDS ARE GOOD ENOUGH TO WARRANT A MENTION YET.

THUS WILL JUST KEEP SKIES PARTLY TO MOSTLY CLOUDY THROUGH THE
PERIOD. NOT SURE THAT PARTLY CLOUDY CONDITIONS WILL REALLY
HAPPEN...BUT SOME HOLES COULD DEVELOP IN THE SKY COVER LIKE WHAT IS
HAPPENING AT THE MOMENT.

FOR TEMPERATURES...GENERALLY STAYED COOLER THAN MAV MOS FOR HIGHS
DUE TO EXPECTED CLOUD COVER. FOR LOWS STUCK WITH A BLEND.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....TDUD/JP
AVIATION...CP

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000
FXUS63 KIWX 190521
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1221 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH WILL BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM EST FRI DEC 19 2014

WEAK SFC TROUGH NOW ACROSS FAR SOUTHERN LOWER MI WILL DROP INTO
NORTHERN IN THIS MORNING. THIS FEATURE AND SOME LAKE ENHANCEMENT
WILL LIKELY BRING A FEW SNOW SHOWERS AND POTENTIALLY PATCHY
FREEZING DRIZZLE TO MAINLY KSBN EARLY THIS MORNING. MAINLY
DRY/CLOUDY THEREAFTER AS TROUGH BECOMES INCREASINGLY DIFFUSE WITH
HIGH PRESSURE BECOMING BETTER ESTABLISHED. OTHERWISE...MVFR CIGS
EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD (MAY SEE BRIEF
IMPROVEMENT TO LOW VFR TOWARD MIDDAY/AFTERNOON) GIVEN RESIDUAL
MOISTURE UNDER LINGERING LOW LEVEL THERMAL INVERSION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...STEINWEDEL
SHORT TERM...JT
LONG TERM...AGD
AVIATION...STEINWEDEL


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000
FXUS63 KIWX 190521
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1221 AM EST FRI DEC 19 2014

.SYNOPSIS...
ISSUED AT 1220 AM EST FRI DEC 19 2014

A WEAK TROUGH WILL BRING LIGHT SCATTERED SNOW SHOWERS AND PATCHY
DRIZZLE TO FAR NORTHERN INDIANA AND SOUTHERN MICHIGAN EARLY THIS
MORNING. OTHERWISE...A RIDGE OF HIGH PRESSURE WILL BRING DRY
CONDITIONS TO THE REGION THROUGH THE WEEKEND WITH NEAR SEASONABLE
TEMPERATURES.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1220 AM EST FRI DEC 19 2014

WEAK SFC TROUGH NOW ACROSS FAR SOUTHERN LOWER MI WILL DROP INTO
NORTHERN IN THIS MORNING. THIS FEATURE AND SOME LAKE ENHANCEMENT
WILL LIKELY BRING A FEW SNOW SHOWERS AND POTENTIALLY PATCHY
FREEZING DRIZZLE TO MAINLY KSBN EARLY THIS MORNING. MAINLY
DRY/CLOUDY THEREAFTER AS TROUGH BECOMES INCREASINGLY DIFFUSE WITH
HIGH PRESSURE BECOMING BETTER ESTABLISHED. OTHERWISE...MVFR CIGS
EXPECTED TO PERSIST THROUGH MUCH OF THE PERIOD (MAY SEE BRIEF
IMPROVEMENT TO LOW VFR TOWARD MIDDAY/AFTERNOON) GIVEN RESIDUAL
MOISTURE UNDER LINGERING LOW LEVEL THERMAL INVERSION.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...STEINWEDEL
SHORT TERM...JT
LONG TERM...AGD
AVIATION...STEINWEDEL


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

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000
FXUS63 KIND 190446
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1146 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190446
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1146 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190446
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1146 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190446
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1146 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190600Z TAF ISSUANCE/...

ISSUED AT 1141 PM EST THU DEC 18 2014

HIGH PRESSURE BUILDING INTO THE AREA WILL KEEP WINDS LIGHT TO CALM
THROUGH THE PERIOD. BASED ON SATELLITE OBSERVATIONS AND TIME
HEIGHT CROSS SECTIONS EXPECT CEILINGS TO BOUNCE BETWEEN MVFR AND
VFR FOR THE NEXT FEW HOURS AT LEAST. COULD SEE VFR AFTER THAT FOR
AWHILE BUT UNCERTAINTY IS STILL PRETTY HIGH. KEPT A SCATTERED DECK
AROUND 2500 FT GOING THROUGH THE PERIOD AS COMPLETE CLEARING SEEMS
UNLIKELY. ALSO INCLUDED A FEW HOURS OF MVFR VISIBILITIES AT KBMG
AS THEY HAVE ALREADY SEEN NUMBERS DROP A BIT AND CALM WINDS WILL
NOT BE MIXING ANYTHING.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190258
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
958 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190258
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
958 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 955 PM EST THU DEC 18 2014

0250Z UPDATE...FORECAST APPEARS TO BE IN GOOD SHAPE. FLURRIES ARE
WANING/EXITING THE AREA BUT LEFT IN MENTION FOR THE NEXT COUPLE
HOURS. OTHER THAN A FEW TWEAKS TO CURRENT TEMP/DEW POINT AND SKY
COVER TRENDS DID NOT NEED TO MAKE ANY MAJOR CHANGES TO THE
OVERNIGHT PERIOD. PREVIOUS DISCUSSION FOLLOWS.

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...SMF/PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190244
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
944 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 190244
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
944 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 190244
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
944 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 190244
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
944 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 940 PM EST THU DEC 18 2014

LATE EVENING UPDATE WILL BE SENT SHORTLY TO EXPAND PATCHY FREEZING
DRIZZLE MENTION SOUTHWARD ACROSS FAR NORTHERN INDIANA DURING THE
EARLY OVERNIGHT HOURS. SOME REPORTS OF SLICK CONDITIONS HAVE BEEN
RECEIVED JUST NORTH OF FORECAST AREA ACROSS SOUTHERN LOWER
MICHIGAN. BASED ON CURRENT OBSERVATIONAL TRENDS AND CONTINUED
PROFILES SUPPORTIVE OF -FZDZ HAVE EXPANDED MENTION ACROSS FAR
NORTHERN INDIANA. WILL HOLD OFF ON ADVISORY AT THIS TIME WITH
STILL SOME LOWER CONFIDENCE ON EXTENT OF HAZARDOUS
CONDITIONS...BUT HAVE ISSUED SPS TO COVER -FZDZ THREAT OVER THE NEXT
FEW HOURS.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
AVIATION...MARSILI


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

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000
FXUS63 KIND 190222
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...CP

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

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WWW.YOUTUBE.COM/NWSINDIANAPOLIS









000
FXUS63 KIND 190222
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...CP

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 190222
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...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 190222
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
922 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT
ACCUMULATIONS WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190300Z TAF ISSUANCE/...

ISSUED AT 922 PM EST THU DEC 18 2014

CEILINGS CONTINUE TO BOUNCE BETWEEN MVFR AND VFR SO WENT WITH A
TEMPO GROUP AT KIND FOR THE NEXT FEW HOURS INDICATING THE
VARIABILITY WITH THE UPDATE. PREVIOUS DISCUSSION FOLLOWS...

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...CP

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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000
FXUS63 KIWX 190055
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
755 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH WILL DROP INTO SOUTHWEST LOWER MICHIGAN LATE
THIS EVENING ALLOWING FOR SCATTERED SNOW SHOWERS TO CONTINUE
SOUTHWARD PROGRESSION INTO NORTHWEST PORTIONS OF THE AREA. UPPER
LEVEL SHORT WAVE TROUGH DROPPING ACROSS SOUTHEAST ONTARIO/NORTHERN
LAKE HURON NOT LIKELY TO MAKE MUCH SOUTHWARD PROGRESS OVERNIGHT
WITH WEAK SHORT WAVE RIDGING BUILDING INTO THE WESTERN GREAT LAKES
TOWARD MORNING. LAKE EFFECT PARAMETERS STILL LOOK ON THE MEAGER
SIDE WITH LOW INVERSION HEIGHTS/DRY MID LEVEL AIR. WITH UPSTREAM
TROUGH CONTINUING TO SHEAR OUT AND LOSE SOUTHWARD PROGRESSION
OVERNIGHT...LIMITED DEPTH OF MOISTURE APPEARS TO SUPPORT AT LEAST
SOME THREAT OF LIGHT FREEZING DRIZZLE...WHICH HAS ALSO BEEN NOTED
IN RECENT UPSTREAM SFC OBS ACROSS SRN LOWER MICHIGAN. HAVE
MAINTAINED PREVIOUS LOW TO MID RANGE SCT -SHSN POPS TONIGHT IN
VICINITY OF LAKE MICHIGAN AND ADDED CHANCE -FZDZ ACROSS SOUTHWEST
LOWER MICHIGAN. CURRENTLY NOT EXPECTING ANY PATCHY FREEZING DRIZZLE
TO BE SIGNIFICANTLY IMPACTFUL GIVEN RELATIVELY DRY SUBCLOUD LAYER.
HAVE HELD OFF ON -FZDZ INCLUSION FOR NW INDIANA AND WILL MONITOR
UPSTREAM TRENDS TO DETERMINE IF THIS MENTION NEEDS TO EXPANDED
SOUTHWARD OVERNIGHT FOLLOWING PROGRESSION OF THE TROUGH. HAVE
MAINTAINED PREVIOUS ACCUMULATIONS OF A TENTH OF AN INCH OR
TWO...WITH BEST CHANCE OF THIS DUSTING IN VICINITY OF SFC TROUGH
AS IT PROGRESSES SOUTHWARD OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 190055
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
755 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH WILL DROP INTO SOUTHWEST LOWER MICHIGAN LATE
THIS EVENING ALLOWING FOR SCATTERED SNOW SHOWERS TO CONTINUE
SOUTHWARD PROGRESSION INTO NORTHWEST PORTIONS OF THE AREA. UPPER
LEVEL SHORT WAVE TROUGH DROPPING ACROSS SOUTHEAST ONTARIO/NORTHERN
LAKE HURON NOT LIKELY TO MAKE MUCH SOUTHWARD PROGRESS OVERNIGHT
WITH WEAK SHORT WAVE RIDGING BUILDING INTO THE WESTERN GREAT LAKES
TOWARD MORNING. LAKE EFFECT PARAMETERS STILL LOOK ON THE MEAGER
SIDE WITH LOW INVERSION HEIGHTS/DRY MID LEVEL AIR. WITH UPSTREAM
TROUGH CONTINUING TO SHEAR OUT AND LOSE SOUTHWARD PROGRESSION
OVERNIGHT...LIMITED DEPTH OF MOISTURE APPEARS TO SUPPORT AT LEAST
SOME THREAT OF LIGHT FREEZING DRIZZLE...WHICH HAS ALSO BEEN NOTED
IN RECENT UPSTREAM SFC OBS ACROSS SRN LOWER MICHIGAN. HAVE
MAINTAINED PREVIOUS LOW TO MID RANGE SCT -SHSN POPS TONIGHT IN
VICINITY OF LAKE MICHIGAN AND ADDED CHANCE -FZDZ ACROSS SOUTHWEST
LOWER MICHIGAN. CURRENTLY NOT EXPECTING ANY PATCHY FREEZING DRIZZLE
TO BE SIGNIFICANTLY IMPACTFUL GIVEN RELATIVELY DRY SUBCLOUD LAYER.
HAVE HELD OFF ON -FZDZ INCLUSION FOR NW INDIANA AND WILL MONITOR
UPSTREAM TRENDS TO DETERMINE IF THIS MENTION NEEDS TO EXPANDED
SOUTHWARD OVERNIGHT FOLLOWING PROGRESSION OF THE TROUGH. HAVE
MAINTAINED PREVIOUS ACCUMULATIONS OF A TENTH OF AN INCH OR
TWO...WITH BEST CHANCE OF THIS DUSTING IN VICINITY OF SFC TROUGH
AS IT PROGRESSES SOUTHWARD OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 190055
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
755 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH WILL DROP INTO SOUTHWEST LOWER MICHIGAN LATE
THIS EVENING ALLOWING FOR SCATTERED SNOW SHOWERS TO CONTINUE
SOUTHWARD PROGRESSION INTO NORTHWEST PORTIONS OF THE AREA. UPPER
LEVEL SHORT WAVE TROUGH DROPPING ACROSS SOUTHEAST ONTARIO/NORTHERN
LAKE HURON NOT LIKELY TO MAKE MUCH SOUTHWARD PROGRESS OVERNIGHT
WITH WEAK SHORT WAVE RIDGING BUILDING INTO THE WESTERN GREAT LAKES
TOWARD MORNING. LAKE EFFECT PARAMETERS STILL LOOK ON THE MEAGER
SIDE WITH LOW INVERSION HEIGHTS/DRY MID LEVEL AIR. WITH UPSTREAM
TROUGH CONTINUING TO SHEAR OUT AND LOSE SOUTHWARD PROGRESSION
OVERNIGHT...LIMITED DEPTH OF MOISTURE APPEARS TO SUPPORT AT LEAST
SOME THREAT OF LIGHT FREEZING DRIZZLE...WHICH HAS ALSO BEEN NOTED
IN RECENT UPSTREAM SFC OBS ACROSS SRN LOWER MICHIGAN. HAVE
MAINTAINED PREVIOUS LOW TO MID RANGE SCT -SHSN POPS TONIGHT IN
VICINITY OF LAKE MICHIGAN AND ADDED CHANCE -FZDZ ACROSS SOUTHWEST
LOWER MICHIGAN. CURRENTLY NOT EXPECTING ANY PATCHY FREEZING DRIZZLE
TO BE SIGNIFICANTLY IMPACTFUL GIVEN RELATIVELY DRY SUBCLOUD LAYER.
HAVE HELD OFF ON -FZDZ INCLUSION FOR NW INDIANA AND WILL MONITOR
UPSTREAM TRENDS TO DETERMINE IF THIS MENTION NEEDS TO EXPANDED
SOUTHWARD OVERNIGHT FOLLOWING PROGRESSION OF THE TROUGH. HAVE
MAINTAINED PREVIOUS ACCUMULATIONS OF A TENTH OF AN INCH OR
TWO...WITH BEST CHANCE OF THIS DUSTING IN VICINITY OF SFC TROUGH
AS IT PROGRESSES SOUTHWARD OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
AVIATION...MARSILI


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

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIWX 190055
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
755 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK UPPER LEVEL DISTURBANCE DROPPING ACROSS THE SOUTHERN GREAT
LAKES WILL BRING SOME SCATTERED LIGHT SNOW SHOWERS TO SOUTHERN
LOWER MICHIGAN AND NORTHWEST INDIANA TONIGHT. OTHERWISE...A RIDGE
OF HIGH PRESSURE WILL BRING DRY CONDITIONS TO THE REGION THROUGH
THE WEEKEND WITH NEAR SEASONABLE TEMPERATURES. LOW TEMPERATURES
TONIGHT WILL DROP INTO THE LOWER TO MID 20S WITH HIGHS ON FRIDAY
REACHING INTO THE LOWER TO MID 30S.

&&

.UPDATE...
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH WILL DROP INTO SOUTHWEST LOWER MICHIGAN LATE
THIS EVENING ALLOWING FOR SCATTERED SNOW SHOWERS TO CONTINUE
SOUTHWARD PROGRESSION INTO NORTHWEST PORTIONS OF THE AREA. UPPER
LEVEL SHORT WAVE TROUGH DROPPING ACROSS SOUTHEAST ONTARIO/NORTHERN
LAKE HURON NOT LIKELY TO MAKE MUCH SOUTHWARD PROGRESS OVERNIGHT
WITH WEAK SHORT WAVE RIDGING BUILDING INTO THE WESTERN GREAT LAKES
TOWARD MORNING. LAKE EFFECT PARAMETERS STILL LOOK ON THE MEAGER
SIDE WITH LOW INVERSION HEIGHTS/DRY MID LEVEL AIR. WITH UPSTREAM
TROUGH CONTINUING TO SHEAR OUT AND LOSE SOUTHWARD PROGRESSION
OVERNIGHT...LIMITED DEPTH OF MOISTURE APPEARS TO SUPPORT AT LEAST
SOME THREAT OF LIGHT FREEZING DRIZZLE...WHICH HAS ALSO BEEN NOTED
IN RECENT UPSTREAM SFC OBS ACROSS SRN LOWER MICHIGAN. HAVE
MAINTAINED PREVIOUS LOW TO MID RANGE SCT -SHSN POPS TONIGHT IN
VICINITY OF LAKE MICHIGAN AND ADDED CHANCE -FZDZ ACROSS SOUTHWEST
LOWER MICHIGAN. CURRENTLY NOT EXPECTING ANY PATCHY FREEZING DRIZZLE
TO BE SIGNIFICANTLY IMPACTFUL GIVEN RELATIVELY DRY SUBCLOUD LAYER.
HAVE HELD OFF ON -FZDZ INCLUSION FOR NW INDIANA AND WILL MONITOR
UPSTREAM TRENDS TO DETERMINE IF THIS MENTION NEEDS TO EXPANDED
SOUTHWARD OVERNIGHT FOLLOWING PROGRESSION OF THE TROUGH. HAVE
MAINTAINED PREVIOUS ACCUMULATIONS OF A TENTH OF AN INCH OR
TWO...WITH BEST CHANCE OF THIS DUSTING IN VICINITY OF SFC TROUGH
AS IT PROGRESSES SOUTHWARD OVERNIGHT.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 750 PM EST THU DEC 18 2014

A WEAK SFC TROUGH DROPPING SOUTHWARD ACROSS SOUTHERN LOWER
MICHIGAN WILL EVENTUALLY REACH NORTHWEST/NORTH CENTRAL INDIANA
OVERNIGHT. SOME LAKE ENHANCEMENT WITH THIS TROUGH WILL LIKELY
PROVIDE A PERIOD OF SNOW SHOWERS AT KSBN PARTICULARLY IN THE 04Z-
08Z TIMEFRAME. HAVE MAINTAINED MVFR VSBYS RESTRICTIONS WITH THE
SNOW SHOWERS DURING THIS PERIOD...ALTHOUGH VERY BRIEF IFR VSBYS
ARE A POSSIBILITY. OTHERWISE...MVFR CIGS ARE EXPECTED TO HOLD
OVERNIGHT AT TERMINALS...GENERALLY AOA 2K FT. DID INCLUDE CIGS
BELOW 2K FT IN ASSOCIATION WITH SCATTERED SNOW SHOWERS AT KSBN IN
THAT 04Z-08Z PERIOD. SOME IMPROVEMENT TO HIGHER END MVFR OR VFR
CIGS BY MIDDAY FRIDAY...BUT GIVEN LINGERING LOW INVERSION HEIGHTS
WILL MAINTAIN MVFR CONDITIONS THROUGH THIS PERIOD.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

UPDATE...MARSILI
SYNOPSIS...MARSILI
SHORT TERM...JT
LONG TERM...AGD
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 182251
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
551 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT ACCUMULATIONS
WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR 190000Z TAF ISSUANCE/...

ISSUED AT 545 PM EST THU DEC 18 2014

SITES WILL START OUT WITH MAINLY MVFR CEILINGS BUT COULD BOUNCE
BETWEEN THAT AND VFR FOR SEVERAL HOURS THIS EVENING AS DRY AIR
TRIES TO WORK INTO THE AREA WITH HIGH PRESSURE BUILDING IN AT THE
SURFACE BUT THE INVERSION FROM THE HIGH CONTINUES TO TRAP THE
LEFTOVER LOW LEVEL MOISTURE. WILL PROBABLY SEE DECKS SCATTER
HIGHER DURING THE OVERNIGHT. LOOKING AT TIME HEIGHTS EXPECT AT
LEAST A SCATTERED LOWER LEVEL DECK TO FORM AGAIN DURING THE DAY
FRIDAY BUT STILL UNCERTAIN WHETHER COVERAGE WILL GO TO BROKEN SO
WILL JUST INCLUDE SCT FOR NOW. WINDS WILL BE LIGHT AROUND 5 KTS OR
LESS THROUGH THE PERIOD.

&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...CP

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 182041
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
341 PM EST THU DEC 18 2014

.UPDATE...
AVIATION SECTION UPDATED.

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT ACCUMULATIONS
WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR THE 182100Z IND TAF UPDATE/...

ONGOING TAF IN VERY GOOD SHAPE. MVFR WILL CONTINUE.

SHORT WAVE EXITING INDIANA AND -SHSN/--SHSN EXPECTED TO DIMINISH
AS THE AFTERNOON AND EVENING PROGRESS. WILL KEEP MVFR CIGS IN
PLACE ACROSS TAF SITES AS PLENTIFUL CLOUDS REMAIN UPSTREAM ALONG
WITH ONGOING MILD COLD AIR ADVECTION.

PREVIOUS DISCUSSION BELOW

/DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...TDUD

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 182041
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
341 PM EST THU DEC 18 2014

.UPDATE...
AVIATION SECTION UPDATED.

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT ACCUMULATIONS
WILL BE POSSIBLE.

&&

.AVIATION /DISCUSSION FOR THE 182100Z IND TAF UPDATE/...

ONGOING TAF IN VERY GOOD SHAPE. MVFR WILL CONTINUE.

SHORT WAVE EXITING INDIANA AND -SHSN/--SHSN EXPECTED TO DIMINISH
AS THE AFTERNOON AND EVENING PROGRESS. WILL KEEP MVFR CIGS IN
PLACE ACROSS TAF SITES AS PLENTIFUL CLOUDS REMAIN UPSTREAM ALONG
WITH ONGOING MILD COLD AIR ADVECTION.

PREVIOUS DISCUSSION BELOW

/DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....TDUD/JP
AVIATION...TDUD

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSINDIANAPOLIS
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIWX 182023
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
323 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 314 PM EST THU DEC 18 2014

HIGH PRESSURE OVER THE UPPER MIDWEST WILL MOVE SLOWLY EAST
PROVIDING FAIR WEATHER WITH SEASONABLE TEMPERATURES THROUGH THE
WEEKEND. THE ONLY EXCEPTION WILL BE A CHANCE OF LAKE EFFECT SNOW
SHOWERS NEAR LAKE MICHIGAN INTO EARLY FRIDAY. LOWS TONIGHT WILL BE
IN THE LOWER AND MIDDLE 20S AND HIGHS FRIDAY WILL BE IN THE LOWER
AND MIDDLE 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1229 PM EST THU DEC 18 2014

WKNG SHRTWV MOVG EAST THROUGH THE OH VALLEY TODAY PROVIDING WK LIFT
WHICH COMBINED WITH LINGERING LOW LEVEL MOISTURE WAS CAUSING SOME
LIGHT SNOW WITH OCNL MVFR VSBY RESTRICTIONS. LACK OF MID LEVEL
MOISTURE SUGGESTS SOME POTENTIAL FOR VERY LIGHT -FZDZ AS WELL BUT
GIVEN PREDOMINANTLY -SN SFC OBS ATTM OPTED TO KEEP THIS OUT OF THE
18Z TAF. A BAND OF LAKE ENHANCED -SHSN ALONG A WK TROF MOVG SOUTH
ACROSS SRN LAKE MICHIGAN IS EXPECTED TO IMPACT SBN TONIGHT WITH A
BRIEF PERIOD OF -SHSN WITH MVFR VSBY RESTRICTIONS AND PSBLY LIGHT
ACCUMS. OTRWS LOW CLOUDS SHOULD REMAIN TRAPPED BENEATH INVERSION
THROUGH TONIGHT... WITH DIMINISHING CLOUD TEND FRIDAY AS DRIER AIR
FILTERS IN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
AVIATION...JT


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

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






000
FXUS63 KIWX 182023
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
323 PM EST THU DEC 18 2014

.SYNOPSIS...
ISSUED AT 314 PM EST THU DEC 18 2014

HIGH PRESSURE OVER THE UPPER MIDWEST WILL MOVE SLOWLY EAST
PROVIDING FAIR WEATHER WITH SEASONABLE TEMPERATURES THROUGH THE
WEEKEND. THE ONLY EXCEPTION WILL BE A CHANCE OF LAKE EFFECT SNOW
SHOWERS NEAR LAKE MICHIGAN INTO EARLY FRIDAY. LOWS TONIGHT WILL BE
IN THE LOWER AND MIDDLE 20S AND HIGHS FRIDAY WILL BE IN THE LOWER
AND MIDDLE 30S.

&&

.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

DRY SUB-CLOUD LAYER HAS THUS FAR KEPT PRECIP ASSOCIATED WITH WK OH
VALLEY SHRTWV ALL SNOW GRAINS AS OPPOSED TO FREEZING DRIZZLE IN
OUR AREA. STILL SOME FLURRIES BEING REPORTED OVER PORTIONS OF NRN
INDIANA BUT 88D RETURNS WANING THIS AFTN AS APPEARS WK UVM WAS
SHIFTING EASTWARD OUT OF OUR AREA. BAND OF LAKE ENHANCED SNOW
ASSOCIATED WITH WK TROF MOVG THROUGH SRN MI/LM LOCATED FM KBIV-
KGRR SHOULD DROP SOUTH INTO NWRN PORTION OF THE CWA THIS EVE AND
OVERNIGHT. WINDS VEERING TO NORTHERLY BY FRIDAY MORNING MAY
SUPPORT LIGHT SNOW SHOWERS PAST DAYBREAK ACROSS LAPORTE COUNTY
BUT LOWERING INVERSION SHOULD END ANY LAKE EFFECT SNOW BY MIDDAY.
WK LAKE INDUCED INSTABILITY... FAIRLY LOW INVERSION HEIGHTS... AND
LIMITED MOISTURE IN THE DGZ THROUGH THE EVENT SUGGESTS LITTLE
POTENTIAL FOR ACCUM. MOISTURE DEPTH EXPECTED TO INCREASE A BIT AS
TROF MOVES THROUGH AREA SO KEPT PTYPE JUST SNOW. OTRWS CLOUD DECK
TRAPPED BENEATH INVERSION REMAINS RATHER WIDESPREAD ACROSS THE SRN
GRTLKS/MIDWEST THIS AFTN AND WITH WK FLOW AS SFC RIDGE BUILDS INTO
OUR AREA TONIGHT AND FRIDAY... EXPECT MOSTLY CLOUDY SKIES TO
PERSIST. APPEARS BEST CHC FOR SOME SUNSHINE FRIDAY IS ACROSS SRN
MI ZONES AS DRIER AIR FILTERS SOUTHWARD FROM THE UPR GRTLKS. GIVEN
EXPECTED PERSISTENT LOW CLOUD DECK... LEANED TOWARD SMALLER
DIURNAL RANGE GUIDANCE WITH LOWS TONIGHT IN THE L-M20S AND HIGHS
FRI IN THE L-M30S.

&&

.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 314 PM EST THU DEC 18 2014

FOCUS OF THE LONG TERM REMAINS ON POTENTIAL STORM NEXT WEEK WITH
LITTLE SENSIBLE WEATHER CONCERNS THROUGH THE WEEKEND GIVEN
PERSISTENT HIGH PRESSURE OVER THE REGION. HERE IS WHAT WE KNOW:

200 KT PACIFIC JET STREAK...CURRENTLY STILL ON THE OTHER SIDE OF THE
INTERNATIONAL DATE LINE...WILL EVENTUALLY WORK ITS WAY INTO THE
CENTRAL CONUS AND CARVE OUT A DEEP LONGWAVE TROUGH. DIGGING TROUGH
WILL BECOME NEGATIVELY TILTED...AND EVENTUALLY CLOSED OFF...BY
CHRISTMAS EVE. STRONG UPPER DIVERGENCE ON THE NOSE OF THIS
CYCLONICALLY CURVED JET STREAK WILL WORK IN TANDEM WITH IMPRESSIVE
DIFFLUENCE AND MIDLEVEL CVA TO SUPPORT A DEEP SURFACE LOW SOMEWHERE
OVER THE GREAT LAKES/NORTHEAST CONUS CHRISTMAS EVE INTO CHRISTMAS
DAY.

WHAT WE DON`T KNOW IS THE EXACT TRACK AND EVOLUTION OF THIS TROUGH
AND ASSOCIATED SURFACE LOW(S). MODEL ACCURACY IN THESE FINER SCALE
DETAILS IS VERY LOW BEYOND 3-4 DAYS...LARGELY DUE TO THE FACT THAT
THE RELEVANT SYNOPTIC DRIVERS ARE STILL OVER THE DATA-SPARSE NORTH
PACIFIC. LATEST 12Z NWP SUITE CONTINUES TO OFFER AN INCONSISTENT
PICTURE REGARDING THE SPECIFIC DETAILS OF THIS EVENT. THAT BEING
SAID...IT CAN BE USEFUL TO NOTE THE TRENDS AND THE TREND OVER THE
PAST FEW CYCLES HAS GENERALLY BEEN A WARMER TRACK FOR OUR CWA AND
LATER PHASING. THIS WOULD RESULT IN THE BULK OF PRECIP FALLING AS
RAIN IN OUR AREA. NOTABLY LACKING WITH THIS EVENT IS A SOURCE OF
VERY COLD AIR UPSTREAM. DEEPENING LOW WILL CERTAINLY PULL IN SOME
BELOW FREEZING TEMPERATURES EVENTUALLY BUT THIS MAY TAKE SOME TIME
AND WITH A SURFACE LOW TRACK DIRECTLY OVERHEAD OR JUST TO OUR
NORTHWEST...MAY ARRIVE AFTER THE BULK OF THE PRECIP/FORCING HAS
EXITED. THIS IS THE SOLUTION CHAMPIONED BY THE LATEST 12Z GFS AND
SIMILARLY BY THE ECMWF...SUGGESTING JUST SOME LIGHT SNOW SHOWERS AND
PERHAPS SOME GUSTY WINDS ON THE 24TH. THOUGH IT SHOULD ALSO BE NOTED
THE LATEST GFS AND ECMWF NOW BRING A SECONDARY LOW THROUGH THE
REGION ON FRIDAY THE 26TH WITH A BETTER CHANCE OF ACCUMULATING
SNOWFALL.

BOTTOMLINE...THERE WILL BE A STRONG STORM SOMEWHERE OVER THE REGION
DURING THE MIDDLE TO END OF NEXT WEEK BUT IMPORTANT DETAILS
REGARDING TIMING...PRECIP TYPES...AND AMOUNTS IN OUR LOCAL AREA
REMAIN UNCLEAR. TO ECHO THE SENTIMENTS OF THE PREVIOUS
FORECASTER...RESTRAINT SHOULD BE EXERCISED IN FORECASTING EXACT SNOW
AMOUNTS AND WITH PLACING MUCH VALUE IN ANY ONE PARTICULAR MODEL
ITERATION. SUFFICE IT TO SAY...ANYONE WITH TRAVEL PLANS DURING THIS
TIME SHOULD STAY TUNED TO THE LATEST FORECAST AND BE PREPARED FOR
HAZARDOUS WEATHER CONDITIONS.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1229 PM EST THU DEC 18 2014

WKNG SHRTWV MOVG EAST THROUGH THE OH VALLEY TODAY PROVIDING WK LIFT
WHICH COMBINED WITH LINGERING LOW LEVEL MOISTURE WAS CAUSING SOME
LIGHT SNOW WITH OCNL MVFR VSBY RESTRICTIONS. LACK OF MID LEVEL
MOISTURE SUGGESTS SOME POTENTIAL FOR VERY LIGHT -FZDZ AS WELL BUT
GIVEN PREDOMINANTLY -SN SFC OBS ATTM OPTED TO KEEP THIS OUT OF THE
18Z TAF. A BAND OF LAKE ENHANCED -SHSN ALONG A WK TROF MOVG SOUTH
ACROSS SRN LAKE MICHIGAN IS EXPECTED TO IMPACT SBN TONIGHT WITH A
BRIEF PERIOD OF -SHSN WITH MVFR VSBY RESTRICTIONS AND PSBLY LIGHT
ACCUMS. OTRWS LOW CLOUDS SHOULD REMAIN TRAPPED BENEATH INVERSION
THROUGH TONIGHT... WITH DIMINISHING CLOUD TEND FRIDAY AS DRIER AIR
FILTERS IN.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...NONE.
&&

$$

SYNOPSIS...JT
SHORT TERM...JT
LONG TERM...AGD
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 181945
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
245 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY NIGHT THROUGH WEDNESDAY NIGHT/...

ISSUED AT 232 PM EST THU DEC 18 2014

AN ACTIVE WEATHER PATTERN IS SETTING UP FOR THE EXTENDED PERIOD
AS A CUT-OFF LOW TRAVERSES THE NORTHERN PLAINS LATE IN THE
WEEKEND...SETTLING OVER THE MIDWEST ON MONDAY AND TUESDAY.
MEASURABLE PRECIP IS EXPECTED FROM MONDAY THROUGH WEDNESDAY NIGHT.
INITIALLY...PRECIP WILL BE IN THE FORM OF RAIN FROM MONDAY THROUGH
TUESDAY...TRANSITIONING TO A RAIN/SNOW MIX ON TUESDAY AFTERNOON...AND
FINALLY ALL SNOW BY WEDNESDAY AS COLDER AIR FILTERS IN ON THE BACK
SIDE OF THE SYSTEM. AT THIS TIME...IT APPEARS THAT LIGHT ACCUMULATIONS
WILL BE POSSIBLE.


&&

.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...NONE.

&&

$$

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

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 181917
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
217 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014

EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.

00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.

00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...TDUD

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 181917
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
217 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014

EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.

00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.

00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...TDUD

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 181917
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
217 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014

EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.

00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.

00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...TDUD

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

FOLLOW US ON FACEBOOK...TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 181917
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
217 PM EST THU DEC 18 2014

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

&&

.SYNOPSIS...
ISSUED AT 217 PM EST THU DEC 18 2014

HIGH PRESSURE IN PLACE OVER THE UPPER MIDWEST AND THE OHIO VALLEY
WILL RESULT IN MAINLY DRY WEATHER THE NEXT COUPLE OF DAYS AS IT
SLOWLY PUSHES EAST THROUGH THE REGION.

A SERIES OF UPPER LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH
THROUGH THE OHIO VALLEY ON FRIDAY NIGHT AND SATURDAY NIGHT. THIS
WILL KEEP PLENTY OF CLOUDS IN PLACE ACROSS CENTRAL INDIANA INTO
THE WEEKEND ALONG WITH TEMPERATURES AT OR BELOW NORMALS.

THE NEXT BEST CHANCE FOR SIGNIFICANT PRECIPITATION WILL BE ON
TUESDAY INTO WEDNESDAY AS A DEEP UPPER TROUGH IS EXPECTED TO PUSH
INTO THE OHIO VALLEY FROM THE GREAT PLAINS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 217 PM EST THU DEC 18 2014

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS LARGE HIGH PRESSURE
STRETCHING FROM THE UPPER MIDWEST ACROSS INDIANA INTO THE
TENNESSEE VALLEY. RADAR SHOWS AREA OF LIGHT SNOW SHOWERS OVER
CENTRAL INDIANA...QUICKLY MOVING TO THE EAST. SURFACE OBS FAIL TO
SHOW MUCH IN THE WAY OF PRECIP REACHING THE GROUND.

MINIMAL ISENTROPIC LIFT AS SEEN ON THE 290K SURFACE WANES THIS
EVENING...AS A WEAK SHORT WAVE ALOFT QUICKLY DEPARTS TO THE EAST.
SATELLITE IMAGES CONTINUE TO SHOW PLENTIFUL CLOUDS UPSTREAM AND THE
SURFACE HIGH REMAINS RATHER DIRTY AS MINIMAL COLD AIR ADVECTION IS
ONGOING. THUS WILL TREND TOWARD A CLOUDY SKY OVERNIGHT WITH LOWS AT
OR BELOW MAVMOS.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 217 PM EST THU DEC 18 2014

MAIN FORECAST CHALLENGE DURING THIS PERIOD WILL BE TEMPS. MODELS
CONTINUE TO SUGGEST QUICK WESTERLY FLOW ALOFT IN THE WAKE OF A
WEAK TROUGH OVER THE WESTERN UNITED STATES. MODELS SUGGEST THE
TROUGH ALOFT FLATTENS OUT AS THE FLOW BECOMES MORE ZONAL BY
SUNDAY. MEANWHILE...SEVERAL WEAK AND UNORGANIZED SHORT WAVE ALOFT
PASS ACROSS THE FORECAST AREA. HIGH PRESSURE AT THE SURFACE WILL
KEEP ANY GULF MOISTURE FROM REACHING THE AREA AND AS THE HIGH
DEPARTS SLOWLY TO THE EAST SURFACE CONVERGENCE AND DYNAMICS APPEAR
RATHER LIMITED. FORECAST SOUNDINGS CONTINUE TO SHOW A DRY COLUMN
ACROSS THE AREA. THUS WILL CONTINUE A DRY FORECAST THROUGH THE
PERIOD.

WITH EXTENSIVE CLOUDINESS UPSTREAM AMID THE DIRTY HIGH PRESSURE
SYSTEM AND TIME HEIGHT SECTIONS CONTINUING TO SHOW TRAPPED LOWER
LEVEL MOISTURE...WILL CONTINUE A MOSTLY CLOUDY FORECAST INTO
FRIDAY AND FRIDAY NIGHT. WITH STEADY STATE TEMPERATURE
ADVECTION...WILL TREND HIGH TEMPERATURES TOWARD THE 3 HOURLY TEMPS
AS HEATING WILL BE LIMITED.

LITTLE CHANGE IS EXPECTED ON FRIDAY NIGHT INTO SATURDAY IN THE
LOWER LEVELS AS TIME HEIGHTS CONTINUE TO KEEP PLENTIFUL TRAPPED
LOWER LEVEL MOISTURE. ADDING TO THE CHANCE FOR CLOUD COVER WILL BE
A QUICK MOVING SYSTEM THROUGH THE DEEP SOUTH AS SOME HIGH MOISTURE
SHOULD PUSH THROUGH THE OHIO VALLEY. AGAIN...WILL CONTINUE WITH A
MOSTLY CLOUDY SKY. GIVEN SOME CLOUDS AND STEADY TEMP ADVECTION
WILL TREND LOWS FRIDAY NIGHT AT OR ABOVE GUIDANCE AND TREND HIGHS
ON SATURDAY NEAR THE 3 HOURLY VALUES.

GFS AND NAM SUGGEST WEAK RIDGING TO BUILD ACROSS THE AREA ON
SUNDAY AMID THE MAINLY ZONAL FLOW. AT THE SURFACE HIGH PRESSURE
WILL BE FOUND WELL TO THE EAST...ALLOWING A WARMER SOUTHERLY FLOW
OF AIR TO CENTRAL INDIANA. FORECAST SOUNDINGS CONTINUE TO SUGGEST
HIGH SATURATION THROUGH SUNDAY. THUS WILL CONTINUE THE MOSTLY
CLOUDY TREND ALONG WARMER LOWS THAN MAV COOLER HIGHS THAN MEX.

&&

.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 340 AM EST THU DEC 18 2014

EXTENDED MODELS AND ENSEMBLES AGREE THAT STRONG PACIFIC JET...ARCING
OVER A HIGH AMPLITUDE WEST COAST UPPER RIDGE...WILL DIVE SOUTHEAST
OVER THE CENTRAL UNITED STATES DURING THE EARLY AND MIDDLE PART OF
NEXT WEEK RESULTING IN AN UPPER TROUGH CLOSING INTO AN UPPER LOW AND
INTENSIFYING INTO A VERY STRONG SYSTEM BEFORE IT MOVES INTO
SOUTHEASTERN CANADA ON CHRISTMAS. MODELS WERE NOT TOO FAR OFF
REGARDING STRENGTH AND TIMING OF THIS SYSTEM...SO A BLEND OF THE
FURTHER NORTH 00Z GFS AND FURTHER SOUTH 12Z ECMWF LOOKS GOOD.

00Z MODELS ARE SHOWING AN UPPER TROUGH OVER SOUTHEASTERN SOUTH
DAKOTA OR NORTHWESTERN IOWA AT 00Z TUESDAY WITH BROAD AREA OF UPPER
DIFFLUENT FLOW ALOFT OVER THE OHIO VALLEY AND GREAT LAKES.
MEANWHILE...LOW LEVEL FLOW WILL BE SOUTHERLY BY MONDAY AND OPEN THE
OHIO VALLEY AND GREAT LAKES TO THE GULF RESULTING IN DEEPENING
MOISTURE TO GO ALONG WITH THE UPPER FORCING. THIS WILL BRING RAIN TO
THE AREA BY MONDAY AS WELL AS ABOVE NORMAL TEMPERATURES. THE WARMER
TEMPERATURES AND RAIN WILL BE SHORT-LIVED...HOWEVER AS COLDER AIR
RUSHES IN FROM THE NORTHWEST ON THE BACK END OF THE SYSTEM LATE
TUESDAY OR TUESDAY NIGHT. ALONG WITH THE COLDER AIR...UPPER IMPULSES
WILL MOVE ACROSS THE AREA IN THE CYCLONIC FLOW IN THE WAKE OF THE
DEPARTING STACKED LOW THAT SHOULD MOVE INTO QUEBEC EARLY CHRISTMAS.
THIS SHOULD GENERATE SOME SNOW WITH LIGHT ACCUMULATION POSSIBLE BY
CHRISTMAS EVE.

00Z GFS ENSEMBLE MOS TEMPERATURES LOOK TOO WARM THIS WEEKEND.
STRONGLY PREFER THE COOLER 00Z DECEMBER 17 EUROPEAN ENSEMBLE MEAN
TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 18/1800Z TAF ISSUANCE/...

ISSUED AT 1208 PM EST THU DEC 18 2014

FLIGHT CONDITIONS WILL HOVER RIGHT AROUND THE MVFR/VFR MARK INTO
THE NIGHT. HOWEVER...TIME CROSS SECTIONS ARE LEANING TOWARD DRIER
CONDITIONS AT ALL LEVELS EARLY TOMORROW MORNING. SO...ANTICIPATE
SCATTERING SOME TIME BETWEEN FRI 09-15Z...WHICH IS REFLECTED IN
TAFS. AT THAT POINT...VFR SHOULD BE THE PREVAILING FLIGHT CATEGORY
THROUGH THE REMAINDER OF TAF PERIOD. NORTHWEST WINDS WILL VEER
SLIGHTLY TO THE NORTHEAST LATE TONIGHT...BUT WILL REMAIN LIGHT.


&&

.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM...MK
AVIATION...TDUD

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





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