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000
FXUS63 KIND 231405
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1005 AM EDT WED APR 23 2014

.UPDATE...
AVIATION SECTIONS UPDATED.

&&

.SYNOPSIS...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH PRESSURE WILL KEEP THE WEATHER QUIET THROUGH EARLY THURSDAY. A
FRONTAL SYSTEM WILL MOVE THROUGH THE AREA LATE THURSDAY INTO
THURSDAY NIGHT...WITH THE POTENTIAL FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS. DRY WEATHER WILL QUICKLY RETURN UNTIL LATE
IN THE WEEKEND WHEN A STACKED CLOSED LOW DRIFTS EASTWARD INTO THE
REGION...REMAINING IN THE REGION THROUGH THE REMAINDER OF THE
FORECAST PERIOD AND BRINGING REPEATED CHANCES FOR SHOWERS AND
PERHAPS A STORM OR TWO...ALONG WITH SOMEWHAT DREARY CONDITIONS.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED APR 23 2014

NO CHANGES MADE WITH MORNING UPDATE AS FORECAST IS RIGHT ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...

AFTER STARTING OUT COOL...EXPECT AMPLE SUNSHINE TO HELP TEMPS RISE
TO NEAR 60 IN THE NORTH...AND THE MID TO UPPER 60S SOUTH. THIS IS
NEAR TO SLIGHTLY ABOVE A MOS BLEND...AS RAW MODEL TEMPS LOOKED FAR
TOO COLD BASED ON 850 TEMPS AND LOW LEVEL THICKNESSES. MAY SEE A BIT
OF AN INCREASE IN HIGH CLOUD LATE TODAY...BUT LIKELY TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH WILL KEEP WEATHER QUIET THROUGH AT LEAST EARLY THURSDAY. SOME
GUIDANCE CONTINUES TO WANT TO DEVELOP PRECIP ACROSS THE NORTH
TONIGHT ASSOCIATED WITH AN AREA OF MIDLEVEL FRONTOGENESIS...BUT
AMPLE DRY AIR IN THE LOW LEVELS CONTINUES TO SUGGEST THIS IS
OVERDONE.

SOME ADDITIONAL MODEL DISCREPANCIES HAVE CREPT IN BETWEEN THE OLDER
EURO AND THE NEW GFS ON FRONTAL TIMING THURSDAY INTO THURSDAY
NIGHT...BUT FOR NOW WILL CONTINUE WITH WHAT HAS BEEN THE MOST
CONSISTENT SCENARIO THE LAST SEVERAL DAYS...WITH PRECIP INTO THE
AREA NO EARLIER THAN THURSDAY AFTERNOON IN THE WEST...AND ACROSS THE
ENTIRE AREA THURSDAY EVENING. ALTHOUGH SURFACE BASED INSTABILITY IS
MINIMAL...K INDEX VALUES CONTINUE TO SUGGEST THUNDER IS A GOOD
POSSIBILITY AND WILL CARRY SCATTERED THUNDERSTORMS THURSDAY EVENING.
A STRONG STORM OR TWO CANNOT BE ENTIRELY RULED OUT...BUT WIDESPREAD
SEVERE THREAT DOES NOT APPEAR IN THE CARDS...AND INDEED LATEST
CONVECTIVE OUTLOOK SHIFTS THE THREAT FOR THE DAY FURTHER
SOUTHWEST...WHICH APPEARS REASONABLE.

ON TEMPS...MOS BLEND OR SLIGHTLY ABOVE LOOKS BEST FOR MOST PERIODS
AS RAW MODEL NUMBERS CONTINUE TO LOOK TOO COOL...SIGNIFICANTLY SO IN
SOME PERIODS...BASED ON LOW LEVEL THERMAL PROGS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR THE 231500Z IND TAF UPDATE/...

VFR CONDITIONS WILL CONTINUE. HIGH PRESSURE CENTERED WISCONSIN
WILL CONTINUE TO PROVIDE SINKING AIR AND DRY NORTH FLOW. NO
CHANGES NEEDED TO THE ONGOING FORECAST.

PREVIOUS DISCUSSION BELOW

/DISCUSSION FOR 231200Z TAF ISSUANCE/...
ISSUED AT 629 AM EDT WED APR 23 2014

VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.

HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL DRIFT EAST ACROSS
THE REGION INTO THIS EVENING. MODEL SOUNDINGS AND RH PROGS SHOW
INCREASING MID AND HIGH LEVEL CLOUDS THIS AFTERNOON AHEAD OF AN
APPROACHING WARM FRONT. EXPECT SKIES TO BECOME MOSTLY CLOUDY BY
EARLY EVENING WITH AN AXIS OF DEEP MOISTURE NOTED AT AROUND 10KFT.
CLOUD COVERAGE WILL DECREASE LATE TONIGHT AS THE WARM FRONT PASSES
BY.

NORTHEAST WINDS TODAY WILL REMAIN LESS THAN 10KTS. WINDS WILL
BECOME EASTERLY THIS EVENING...THEN VEER TO THE SOUTHEAST AS THE
WARM FRONT LIFTS NORTH OF THE REGION.


&&

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

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD/CP
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN/JP

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

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







000
FXUS63 KIND 231352
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
950 AM EDT WED APR 23 2014

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

&&

.SYNOPSIS...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH PRESSURE WILL KEEP THE WEATHER QUIET THROUGH EARLY THURSDAY. A
FRONTAL SYSTEM WILL MOVE THROUGH THE AREA LATE THURSDAY INTO
THURSDAY NIGHT...WITH THE POTENTIAL FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS. DRY WEATHER WILL QUICKLY RETURN UNTIL LATE
IN THE WEEKEND WHEN A STACKED CLOSED LOW DRIFTS EASTWARD INTO THE
REGION...REMAINING IN THE REGION THROUGH THE REMAINDER OF THE
FORECAST PERIOD AND BRINGING REPEATED CHANCES FOR SHOWERS AND
PERHAPS A STORM OR TWO...ALONG WITH SOMEWHAT DREARY CONDITIONS.

&&

.NEAR TERM /REST OF TODAY/...
ISSUED AT 950 AM EDT WED APR 23 2014

NO CHANGES MADE WITH MORNING UPDATE AS FORECAST IS RIGHT ON TRACK.
PREVIOUS DISCUSSION FOLLOWS...

AFTER STARTING OUT COOL...EXPECT AMPLE SUNSHINE TO HELP TEMPS RISE
TO NEAR 60 IN THE NORTH...AND THE MID TO UPPER 60S SOUTH. THIS IS
NEAR TO SLIGHTLY ABOVE A MOS BLEND...AS RAW MODEL TEMPS LOOKED FAR
TOO COLD BASED ON 850 TEMPS AND LOW LEVEL THICKNESSES. MAY SEE A BIT
OF AN INCREASE IN HIGH CLOUD LATE TODAY...BUT LIKELY TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON TEMPS.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH WILL KEEP WEATHER QUIET THROUGH AT LEAST EARLY THURSDAY. SOME
GUIDANCE CONTINUES TO WANT TO DEVELOP PRECIP ACROSS THE NORTH
TONIGHT ASSOCIATED WITH AN AREA OF MIDLEVEL FRONTOGENESIS...BUT
AMPLE DRY AIR IN THE LOW LEVELS CONTINUES TO SUGGEST THIS IS
OVERDONE.

SOME ADDITIONAL MODEL DISCREPANCIES HAVE CREPT IN BETWEEN THE OLDER
EURO AND THE NEW GFS ON FRONTAL TIMING THURSDAY INTO THURSDAY
NIGHT...BUT FOR NOW WILL CONTINUE WITH WHAT HAS BEEN THE MOST
CONSISTENT SCENARIO THE LAST SEVERAL DAYS...WITH PRECIP INTO THE
AREA NO EARLIER THAN THURSDAY AFTERNOON IN THE WEST...AND ACROSS THE
ENTIRE AREA THURSDAY EVENING. ALTHOUGH SURFACE BASED INSTABILITY IS
MINIMAL...K INDEX VALUES CONTINUE TO SUGGEST THUNDER IS A GOOD
POSSIBILITY AND WILL CARRY SCATTERED THUNDERSTORMS THURSDAY EVENING.
A STRONG STORM OR TWO CANNOT BE ENTIRELY RULED OUT...BUT WIDESPREAD
SEVERE THREAT DOES NOT APPEAR IN THE CARDS...AND INDEED LATEST
CONVECTIVE OUTLOOK SHIFTS THE THREAT FOR THE DAY FURTHER
SOUTHWEST...WHICH APPEARS REASONABLE.

ON TEMPS...MOS BLEND OR SLIGHTLY ABOVE LOOKS BEST FOR MOST PERIODS
AS RAW MODEL NUMBERS CONTINUE TO LOOK TOO COOL...SIGNIFICANTLY SO IN
SOME PERIODS...BASED ON LOW LEVEL THERMAL PROGS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR 231200Z TAF ISSUANCE/...
ISSUED AT 629 AM EDT WED APR 23 2014

VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.

HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL DRIFT EAST ACROSS
THE REGION INTO THIS EVENING. MODEL SOUNDINGS AND RH PROGS SHOW
INCREASING MID AND HIGH LEVEL CLOUDS THIS AFTERNOON AHEAD OF AN
APPROACHING WARM FRONT. EXPECT SKIES TO BECOME MOSTLY CLOUDY BY
EARLY EVENING WITH AN AXIS OF DEEP MOISTURE NOTED AT AROUND 10KFT.
CLOUD COVERAGE WILL DECREASE LATE TONIGHT AS THE WARM FRONT PASSES
BY.

NORTHEAST WINDS TODAY WILL REMAIN LESS THAN 10KTS. WINDS WILL
BECOME EASTERLY THIS EVENING...THEN VEER TO THE SOUTHEAST AS THE
WARM FRONT LIFTS NORTH OF THE REGION.

&&

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

&&

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD/CP
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN

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

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






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000
FXUS63 KIWX 231047
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
647 AM EDT WED APR 23 2014

.SYNOPSIS...
ISSUED AT 340 AM EDT WED APR 23 2014

CANADIAN HIGH PRESSURE WILL MAINTAIN COOL AND DRY CONDITIONS ACROSS
THE AREA TODAY. HIGH TEMPERATURES WILL GENERALLY BE IN THE MID TO
UPPER 50S WITH COOLER CONDITIONS NEAR THE LAKE. A WEAK WARM FRONT
WILL APPROACH THE REGION TONIGHT AND MAY GENERATE A FEW SPRINKLES
ACROSS NORTHWEST INDIANA AND SOUTHWEST MICHIGAN. OVERNIGHT LOWS ARE
EXPECTED TO HOLD IN THE UPPER 30S TO LOWER 40S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM EDT WED APR 23 2014

CONFLUENT NORTHWEST FLOW ALOFT AND MIDLEVEL HEIGHT RISES/AVA
ASSOCIATED WITH APPROACHING RIDGE WILL LEAD TO A PLEASANT...ALBEIT
COOL...DAY. LOW LEVEL RIDGE AXIS DOES NOT SHIFT EAST OF OUR
LONGITUDE UNTIL THE EVENING...MAINTAINING LIGHT NORTHERLY FLOW FOR
MUCH OF THE DAY. GRADUAL AIRMASS MODIFICATION UNDER MID APRIL SUN
WILL LEAD TO WARMER CONDITIONS THAN YESTERDAY BUT 850MB TEMPS ONLY
CLIMB TO AROUND 2C BY LATE AFTERNOON. THEREFORE MID TO UPPER 50S
SEEM APPROPRIATE FOR NOW WITH FEW CHANGES NECESSARY TO INHERITED
GRIDS. NOTE THIS IS STILL ALMOST A 30 DEGREE DIURNAL SWING FROM
COLD MORNING LOWS. ONSHORE FLOW/LAKE BREEZE WILL KEEP OUR FAR
NORTHWEST ZONES IN THE UPPER 40S/LOWER 50S. WARM FRONT WILL THEN
APPROACH THE REGION BY TONIGHT. 00Z MODELS STILL TRYING TO PUSH
SOME LIGHT QPF INTO OUR CWA BUT EXPECT ANYTHING MORE THAN A FEW
SPRINKLES WILL BE DIFFICULT GIVEN MAGNITUDE OF DRY/STABLE AIR
PRESENT IN THE LOWER LEVELS. SYSTEM RELATIVE 295K ISENTROPIC
ASCENT IS NOT PARTICULARLY IMPRESSIVE AND THERE IS LITTLE TO NO
UPPER JET SUPPORT. SUPPOSE SOME REMNANTS OF UPSTREAM CONVECTION
COULD WASH OVER THE RIDGE INTO OUR WESTERN COUNTIES AND PRODUCE A
FEW RAIN SHOWERS BUT STILL THINK CHANCE SPRINKLES BETTER REFLECTS
THE EXPECTED NATURE OF THE EVENT. OVERNIGHT LOWS WILL ALSO BE
MILDER TONIGHT GIVEN INCREASING CLOUDS...WEAK WAA...AND A WARMER
START TO THE EVENING. RADIATIONAL COOLING POTENTIAL ALSO APPEARS
LOWER TONIGHT AND PREFER TO SHY AWAY FROM COLD MOS GUIDANCE.
EXPECT GENERALLY UPPER 30S TO LOWER 40S WITH LOW FROST POTENTIAL.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM EDT WED APR 23 2014

THURSDAY WILL BE CHARACTERIZED BY STRONG LOW LEVEL WARM ADVECTION IN
ADVANCE OF A PROGRESSIVE EASTERN PACIFIC WAVE THAT WILL IMPACT THE
AREA THURSDAY NIGHT. PLENTIFUL MID/HIGH CLOUDS EXPECTED IN
ASSOCIATION WITH THIS WARM ADVECTION THURSDAY...AND PRESENT
INDICATIONS STILL SUGGEST A RELATIVELY DRY SUBCLOUD LAYER PERSISTING
THROUGH MUCH OF THE DAY. NAM ISENTROPIC ANALYSES DO DEPICT SOME
REDUCED CPD`S ON THE 295K SFC ESPECIALLY ACROSS NORTHERN SECTIONS
THURSDAY MORNING WITH STRONGER WARM ADVECTION WING. NOT COMPLETELY
OUT OF THE QUESTION SOME VERY WEAK ELEVATED INSTABILITY COULD YIELD
A FEW ISOLATED SHOWERS OR SPRINKLES BUT ZONE OF STRONGEST ISENTROPIC
UPGLIDE SHOULD LIFT NORTH OF THE AREA IN THE AFTERNOON. BETTER
CHANCES OF MORE WIDESPREAD RAINFALL WILL HOLD OFF UNTIL EVENING AS
LOW LEVEL THETAE RIDGING/1.25 INCH PWAT AXIS BUILDS IN FROM THE
WEST. GUIDANCE CONTINUES TO DEPICT STRONG LOW LEVEL CONVERGENCE WITH
ASSOCIATED LOW LEVEL TROUGH THURSDAY EVENING...WITH ADDITIONAL
SYNOPTIC SUPPORT FROM A 100 KNOT UPPER JET STREAK NOSING INTO THE MD
MS VALLEY. GIVEN ABOVE FACTORS...AND FAIRLY CONSISTENT RUN TO RUN
SIGNAL...HAVE NUDGED UP TO CATEGORICAL POPS OVERSPREADING THE AREA
WEST TO EAST THURSDAY EVENING. DURATION OF PRECIP SHOULD BE
RELATIVELY SHORT HOWEVER AS PROGRESSIVE NATURE OF THIS SYSTEM ALLOWS
LOW LEVEL MOIST TONGUE TO SHIFT EAST OF THE AREA DURING THE
OVERNIGHT HOURS. STRONG LOW LEVEL CONVERGENCE COULD YIELD SOME
IMPRESSIVE RAINFALL RATES FOR A TIME...BUT ONCE AGAIN PROGRESSIVE
NATURE OF SYSTEM SHOULD LIMIT RAINFALL AMOUNTS TO 0.25-0.50 INCHES.
WILL CONTINUE TO LIMIT TS POTENTIAL TO CHANCE AT THIS TIME...WITH
NAM/GFS BUFFER SOUNDINGS CONTINUING TO DEPICT MEAGER INSTABILITY
PROFILES.

WEAK COLD ADVECTION TO ENSUE FOR LATE THURSDAY NIGHT/FRIDAY MORNING
BEHIND SFC FRONT...ALTHOUGH DEEPER POST-FRONTAL MIXING ON FRIDAY
SHOULD OFFSET SLIGHTLY COOLER LOW LEVEL PROFILES...AND THEN
SOME...WITH HIGHS EXPECTED IN THE UPPER 60S TO POSSIBLY LOWER 70S. A
MUCH DRIER AIR MASS WILL OVERSPREAD THE AREA HOWEVER...AIDED BY
STRONG COLUMN LARGE SCALE SUBSIDENCE. MID LEVEL COLD POCKET
ADVECTING INTO THE SOUTHERN GREAT LAKES FOR FRIDAY SHOULD LEND TO
STEEP LOW/MID LEVEL LAPSE RATES...WITH MAIN UNCERTAINTY IN ANY
LOW END PRECIP CHANCE ON DEPTH OF MIXED LAYER AND BOUNDARY LAYER
MOISTURE. SOME WEAK SYNOPTIC FORCING MAY EXIST ACROSS THE FAR NORTH
ALONG SOUTHERN PERIPHERY OF GREAT LAKES DPVA...BUT WILL KEEP
FORECAST DRY AT THIS POINT WITH EXPECTATION OF ONLY AN INCREASE IN
HIGHER BASED CU FRIDAY AFTERNOON WITH SOME VERTICAL EXTENT GIVEN MID
LEVEL LAPSE RATES. SOME LOW END ISOLD SHRA POTENTIAL MAY EXTEND
SOUTHWARD ACROSS THE REMAINDER OF THE AREA THROUGH FRIDAY EVENING AS
STRONGER 850-700 HPA FRONTOGENESIS SHIFTS SOUTHWARD IN ASSOCIATION
WITH SECONDARY FRONTAL BOUNDARY. GIVEN EXPECTED DEPTH TO MIXED LAYER
FRIDAY DID GO AHEAD AND DROP AFTERNOON DEW PTS A FEW DEGREES CLOSER
TO MOS VALUES WHICH COULD POSE SOME FIRE WEATHER CONCERNS GIVEN
BREEZY/WINDY CONDITIONS. HOWEVER...PROBABLE RAINFALL THURSDAY NIGHT
AND WET SOILS SHOULD TEND TO MITIGATE THIS CONCERN.

MUCH COOLER DAY SHAPING UP FOR SATURDAY...PARTICULARLY ACROSS THE
FAR NORTHWEST WHERE SOUTH CENTRAL CANADIAN HIGH PRESSURE PROVIDES
ONSHORE FLOW...LIKELY KEEPING AFTERNOON HIGHS IN THE MID-UPPER 40S.
MID/UPPER LEVEL FLOW PATTERN TO BECOME LESS PROGRESSIVE/BLOCKY BY
LATER THIS WEEKEND WHICH WILL ALLOW MID LEVEL RIDGING TO MAINTAIN
ITS GRIP ON THE REGION THROUGH MUCH OF THE WEEKEND. WITH MAIN UPPER
TROUGH CUTTING OFF ACROSS THE CENTRAL PLAINS BY LATE
WEEKEND...SOUTHEAST LOW LEVEL FLOW SHOULD TEND TO DELAY SIGNIFICANT
MOISTURE RETURN UNTIL VERY LATE WEEKEND/OR EARLY NEXT WEEK
PARTICULARLY ACROSS THE FAR NORTHEAST. THUS HAVE LOWERED CR ALLBLEND
POPS ACROSS THE NORTHEAST...AND HAVE PUT MORE WEIGHT ON PREVIOUS
FORECAST WITH MAINTENANCE OF LOWER POPS THROUGH SUNDAY AFTERNOON
BEFORE DEEPER MOISTURE ONCE AGAIN ADVECTS INTO THE AREA.

THE LATE SUNDAY THROUGH TUESDAY PERIOD STILL LOOKS TO BE UNSETTLED
AS BROAD UPPER LEVEL NEGATIVE HEIGHT ANOMALY SHOULD PERSIST ACROSS
THE LOWER/MID MS VALLEY WITH OCCLUDED SYSTEM STALLING ACROSS THE
REGION. WHILE SYSTEM WILL BE VERTICALLY STACKED TOWARD THE END OF
THE PERIOD...PRECIP CHANCES TO PERSIST THROUGH THE MIDDLE OF NEXT
WEEK WITH LOCAL AREA POSSIBLY BECOMING POSITIONED IN FAVORABLE FGEN
REGION NORTH OF THE MID LEVEL HEIGHT MINIMUM. WEAK THERMAL RIDGE
SHOULD BE CONTINUE TO WRAP BACK INTO THE LOCAL AREA THROUGH THE END
OF THE PERIOD...BUT INFLUENCES OF CLOUDS/PRECIP SHOULD KEEP TEMPS
BELOW NORMAL FOR MON/TUE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 637 AM EDT WED APR 23 2014

VFR CONDITIONS WILL PERSIST THROUGH THIS FORECAST VALID PERIOD.
LOW LEVEL ANTICYCLONE TO REMAIN JUST WEST OF THE REGION TODAY AND
BECOME ENHANCED OVER LAKE MICHIGAN. THIS WILL KEEP A NORTHERLY
FLOW IN PLACE TODAY...OR PERHAPS NORTH NORTHWEST AT KSBN WITH
DIVERGENT SOUTHERN LAKE MICHIGAN SFC PATTERN ANTICIPATED. HIGH
CLOUDS TO INCREASE THIS AFTERNOON...WITH LOWERING MID LEVEL DECK
TONIGHT AS MID LEVEL WARM ADVECTION RAMPS UP. INCREASING ELEVATED
MOISTURE AND WEAK RIPPLES PROGRESSING THROUGH UPPER RIDGING...MAY
BE ENOUGH FOR SOME SCATTERED VERY LIGHT RAIN SHOWERS OR SPRINKLES
LATE EVENING/OVERNIGHT. HOWEVER...WITH VERY LIMITED SUBCLOUD
MOISTURE AVAILABILITY...WILL KEEP TAFS DRY AT THIS TIME.

&&

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

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...MARSILI
AVIATION...MARSILI


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

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







000
FXUS63 KIND 231029
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
629 AM EDT WED APR 23 2014

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

&&

.SYNOPSIS...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH PRESSURE WILL KEEP THE WEATHER QUIET THROUGH EARLY THURSDAY. A
FRONTAL SYSTEM WILL MOVE THROUGH THE AREA LATE THURSDAY INTO
THURSDAY NIGHT...WITH THE POTENTIAL FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS. DRY WEATHER WILL QUICKLY RETURN UNTIL LATE
IN THE WEEKEND WHEN A STACKED CLOSED LOW DRIFTS EASTWARD INTO THE
REGION...REMAINING IN THE REGION THROUGH THE REMAINDER OF THE
FORECAST PERIOD AND BRINGING REPEATED CHANCES FOR SHOWERS AND
PERHAPS A STORM OR TWO...ALONG WITH SOMEWHAT DREARY CONDITIONS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT WED APR 23 2014

AFTER STARTING OUT COOL...EXPECT AMPLE SUNSHINE TO HELP TEMPS RISE
TO NEAR 60 IN THE NORTH...AND THE MID TO UPPER 60S SOUTH. THIS IS
NEAR TO SLIGHTLY ABOVE A MOS BLEND...AS RAW MODEL TEMPS LOOKED FAR
TOO COLD BASED ON 850 TEMPS AND LOW LEVEL THICKNESSES. MAY SEE A BIT
OF AN INCREASE IN HIGH CLOUD LATE TODAY...BUT LIKELY TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON TEMPS.

WINDS HAVE STAYED UP MUCH OF THE NIGHT AND KEPT TEMPS FROM BOTTOMING
OUT COMPLETELY. MAY HAVE TO CARRY PATCHY FROST FOR AN HOUR OR TWO
THIS MORNING ESPECIALLY FOR SHELTERED AREAS...BUT THAT WILL BE ABOUT
IT.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH WILL KEEP WEATHER QUIET THROUGH AT LEAST EARLY THURSDAY. SOME
GUIDANCE CONTINUES TO WANT TO DEVELOP PRECIP ACROSS THE NORTH
TONIGHT ASSOCIATED WITH AN AREA OF MIDLEVEL FRONTOGENESIS...BUT
AMPLE DRY AIR IN THE LOW LEVELS CONTINUES TO SUGGEST THIS IS
OVERDONE.

SOME ADDITIONAL MODEL DISCREPANCIES HAVE CREPT IN BETWEEN THE OLDER
EURO AND THE NEW GFS ON FRONTAL TIMING THURSDAY INTO THURSDAY
NIGHT...BUT FOR NOW WILL CONTINUE WITH WHAT HAS BEEN THE MOST
CONSISTENT SCENARIO THE LAST SEVERAL DAYS...WITH PRECIP INTO THE
AREA NO EARLIER THAN THURSDAY AFTERNOON IN THE WEST...AND ACROSS THE
ENTIRE AREA THURSDAY EVENING. ALTHOUGH SURFACE BASED INSTABILITY IS
MINIMAL...K INDEX VALUES CONTINUE TO SUGGEST THUNDER IS A GOOD
POSSIBILITY AND WILL CARRY SCATTERED THUNDERSTORMS THURSDAY EVENING.
A STRONG STORM OR TWO CANNOT BE ENTIRELY RULED OUT...BUT WIDESPREAD
SEVERE THREAT DOES NOT APPEAR IN THE CARDS...AND INDEED LATEST
CONVECTIVE OUTLOOK SHIFTS THE THREAT FOR THE DAY FURTHER
SOUTHWEST...WHICH APPEARS REASONABLE.

ON TEMPS...MOS BLEND OR SLIGHTLY ABOVE LOOKS BEST FOR MOST PERIODS
AS RAW MODEL NUMBERS CONTINUE TO LOOK TOO COOL...SIGNIFICANTLY SO IN
SOME PERIODS...BASED ON LOW LEVEL THERMAL PROGS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR 231200Z TAF ISSUANCE/...
ISSUED AT 629 AM EDT WED APR 23 2014

VFR CONDITIONS EXPECTED THROUGHOUT THE FORECAST PERIOD.

HIGH PRESSURE CENTERED OVER THE GREAT LAKES WILL DRIFT EAST ACROSS
THE REGION INTO THIS EVENING. MODEL SOUNDINGS AND RH PROGS SHOW
INCREASING MID AND HIGH LEVEL CLOUDS THIS AFTERNOON AHEAD OF AN
APPROACHING WARM FRONT. EXPECT SKIES TO BECOME MOSTLY CLOUDY BY
EARLY EVENING WITH AN AXIS OF DEEP MOISTURE NOTED AT AROUND 10KFT.
CLOUD COVERAGE WILL DECREASE LATE TONIGHT AS THE WARM FRONT PASSES
BY.

NORTHEAST WINDS TODAY WILL REMAIN LESS THAN 10KTS. WINDS WILL
BECOME EASTERLY THIS EVENING...THEN VEER TO THE SOUTHEAST AS THE
WARM FRONT LIFTS NORTH OF THE REGION.

&&

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

&&

$$

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

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

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








000
FXUS63 KIND 230813
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
412 AM EDT WED APR 23 2014

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH PRESSURE WILL KEEP THE WEATHER QUIET THROUGH EARLY THURSDAY. A
FRONTAL SYSTEM WILL MOVE THROUGH THE AREA LATE THURSDAY INTO
THURSDAY NIGHT...WITH THE POTENTIAL FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS. DRY WEATHER WILL QUICKLY RETURN UNTIL LATE
IN THE WEEKEND WHEN A STACKED CLOSED LOW DRIFTS EASTWARD INTO THE
REGION...REMAINING IN THE REGION THROUGH THE REMAINDER OF THE
FORECAST PERIOD AND BRINGING REPEATED CHANCES FOR SHOWERS AND
PERHAPS A STORM OR TWO...ALONG WITH SOMEWHAT DREARY CONDITIONS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT WED APR 23 2014

AFTER STARTING OUT COOL...EXPECT AMPLE SUNSHINE TO HELP TEMPS RISE
TO NEAR 60 IN THE NORTH...AND THE MID TO UPPER 60S SOUTH. THIS IS
NEAR TO SLIGHTLY ABOVE A MOS BLEND...AS RAW MODEL TEMPS LOOKED FAR
TOO COLD BASED ON 850 TEMPS AND LOW LEVEL THICKNESSES. MAY SEE A BIT
OF AN INCREASE IN HIGH CLOUD LATE TODAY...BUT LIKELY TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON TEMPS.

WINDS HAVE STAYED UP MUCH OF THE NIGHT AND KEPT TEMPS FROM BOTTOMING
OUT COMPLETELY. MAY HAVE TO CARRY PATCHY FROST FOR AN HOUR OR TWO
THIS MORNING ESPECIALLY FOR SHELTERED AREAS...BUT THAT WILL BE ABOUT
IT.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH WILL KEEP WEATHER QUIET THROUGH AT LEAST EARLY THURSDAY. SOME
GUIDANCE CONTINUES TO WANT TO DEVELOP PRECIP ACROSS THE NORTH
TONIGHT ASSOCIATED WITH AN AREA OF MIDLEVEL FRONTOGENESIS...BUT
AMPLE DRY AIR IN THE LOW LEVELS CONTINUES TO SUGGEST THIS IS
OVERDONE.

SOME ADDITIONAL MODEL DISCREPANCIES HAVE CREPT IN BETWEEN THE OLDER
EURO AND THE NEW GFS ON FRONTAL TIMING THURSDAY INTO THURSDAY
NIGHT...BUT FOR NOW WILL CONTINUE WITH WHAT HAS BEEN THE MOST
CONSISTENT SCENARIO THE LAST SEVERAL DAYS...WITH PRECIP INTO THE
AREA NO EARLIER THAN THURSDAY AFTERNOON IN THE WEST...AND ACROSS THE
ENTIRE AREA THURSDAY EVENING. ALTHOUGH SURFACE BASED INSTABILITY IS
MINIMAL...K INDEX VALUES CONTINUE TO SUGGEST THUNDER IS A GOOD
POSSIBILITY AND WILL CARRY SCATTERED THUNDERSTORMS THURSDAY EVENING.
A STRONG STORM OR TWO CANNOT BE ENTIRELY RULED OUT...BUT WIDESPREAD
SEVERE THREAT DOES NOT APPEAR IN THE CARDS...AND INDEED LATEST
CONVECTIVE OUTLOOK SHIFTS THE THREAT FOR THE DAY FURTHER
SOUTHWEST...WHICH APPEARS REASONABLE.

ON TEMPS...MOS BLEND OR SLIGHTLY ABOVE LOOKS BEST FOR MOST PERIODS
AS RAW MODEL NUMBERS CONTINUE TO LOOK TOO COOL...SIGNIFICANTLY SO IN
SOME PERIODS...BASED ON LOW LEVEL THERMAL PROGS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR THE 230900Z TAF UPDATE/...
ISSUED AT 412 AM EDT WED APR 23 2014

MINOR TWEAKS TO WINDS BASED ON OBS...OTHERWISE NO CHANGES NEEDED.

06Z DISCUSSION FOLLOWS.

VFR CONDITIONS ARE EXPECTED TO CONTINUE.

HIGH PRESSURE OVER THE WESTERN GREAT LAKES AND UPPER MIDWEST WILL
CONTINUE TO SLOWLY BUILD EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY DURING THIS PERIOD. TIME HEIGHT SECTIONS AND FORECAST
SOUNDINGS REMAIN VERY DRY...AMID SUBSIDENCE ASSOCIATED WITH THE
PASSING HIGH PRESSURE SYSTEM.

HIGH CLOUDS ARE EXPECTED TO INCREASE AFTER 00Z THURSDAY AS A WARM
FRONT APPROACHES FROM THE WEST. DRY AIR IN PLACE AT THE LOWER
LEVELS WILL CONTINUE TO PROVIDE VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...JP/RYAN

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

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









000
FXUS63 KIWX 230740
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
340 AM EDT WED APR 23 2014

.SYNOPSIS...
ISSUED AT 340 AM EDT WED APR 23 2014

CANADIAN HIGH PRESSURE WILL MAINTAIN COOL AND DRY CONDITIONS ACROSS
THE AREA TODAY. HIGH TEMPERATURES WILL GENERALLY BE IN THE MID TO
UPPER 50S WITH COOLER CONDITIONS NEAR THE LAKE. A WEAK WARM FRONT
WILL APPROACH THE REGION TONIGHT AND MAY GENERATE A FEW SPRINKLES
ACROSS NORTHWEST INDIANA AND SOUTHWEST MICHIGAN. OVERNIGHT LOWS ARE
EXPECTED TO HOLD IN THE UPPER 30S TO LOWER 40S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM EDT WED APR 23 2014

CONFLUENT NORTHWEST FLOW ALOFT AND MIDLEVEL HEIGHT RISES/AVA
ASSOCIATED WITH APPROACHING RIDGE WILL LEAD TO A PLEASANT...ALBEIT
COOL...DAY. LOW LEVEL RIDGE AXIS DOES NOT SHIFT EAST OF OUR
LONGITUDE UNTIL THE EVENING...MAINTAINING LIGHT NORTHERLY FLOW FOR
MUCH OF THE DAY. GRADUAL AIRMASS MODIFICATION UNDER MID APRIL SUN
WILL LEAD TO WARMER CONDITIONS THAN YESTERDAY BUT 850MB TEMPS ONLY
CLIMB TO AROUND 2C BY LATE AFTERNOON. THEREFORE MID TO UPPER 50S
SEEM APPROPRIATE FOR NOW WITH FEW CHANGES NECESSARY TO INHERITED
GRIDS. NOTE THIS IS STILL ALMOST A 30 DEGREE DIURNAL SWING FROM
COLD MORNING LOWS. ONSHORE FLOW/LAKE BREEZE WILL KEEP OUR FAR
NORTHWEST ZONES IN THE UPPER 40S/LOWER 50S. WARM FRONT WILL THEN
APPROACH THE REGION BY TONIGHT. 00Z MODELS STILL TRYING TO PUSH
SOME LIGHT QPF INTO OUR CWA BUT EXPECT ANYTHING MORE THAN A FEW
SPRINKLES WILL BE DIFFICULT GIVEN MAGNITUDE OF DRY/STABLE AIR
PRESENT IN THE LOWER LEVELS. SYSTEM RELATIVE 295K ISENTROPIC
ASCENT IS NOT PARTICULARLY IMPRESSIVE AND THERE IS LITTLE TO NO
UPPER JET SUPPORT. SUPPOSE SOME REMNANTS OF UPSTREAM CONVECTION
COULD WASH OVER THE RIDGE INTO OUR WESTERN COUNTIES AND PRODUCE A
FEW RAIN SHOWERS BUT STILL THINK CHANCE SPRINKLES BETTER REFLECTS
THE EXPECTED NATURE OF THE EVENT. OVERNIGHT LOWS WILL ALSO BE
MILDER TONIGHT GIVEN INCREASING CLOUDS...WEAK WAA...AND A WARMER
START TO THE EVENING. RADIATIONAL COOLING POTENTIAL ALSO APPEARS
LOWER TONIGHT AND PREFER TO SHY AWAY FROM COLD MOS GUIDANCE.
EXPECT GENERALLY UPPER 30S TO LOWER 40S WITH LOW FROST POTENTIAL.

&&

.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM EDT WED APR 23 2014

THURSDAY WILL BE CHARACTERIZED BY STRONG LOW LEVEL WARM ADVECTION IN
ADVANCE OF A PROGRESSIVE EASTERN PACIFIC WAVE THAT WILL IMPACT THE
AREA THURSDAY NIGHT. PLENTIFUL MID/HIGH CLOUDS EXPECTED IN
ASSOCIATION WITH THIS WARM ADVECTION THURSDAY...AND PRESENT
INDICATIONS STILL SUGGEST A RELATIVELY DRY SUBCLOUD LAYER PERSISTING
THROUGH MUCH OF THE DAY. NAM ISENTROPIC ANALYSES DO DEPICT SOME
REDUCED CPD`S ON THE 295K SFC ESPECIALLY ACROSS NORTHERN SECTIONS
THURSDAY MORNING WITH STRONGER WARM ADVECTION WING. NOT COMPLETELY
OUT OF THE QUESTION SOME VERY WEAK ELEVATED INSTABILITY COULD YIELD
A FEW ISOLATED SHOWERS OR SPRINKLES BUT ZONE OF STRONGEST ISENTROPIC
UPGLIDE SHOULD LIFT NORTH OF THE AREA IN THE AFTERNOON. BETTER
CHANCES OF MORE WIDESPREAD RAINFALL WILL HOLD OFF UNTIL EVENING AS
LOW LEVEL THETAE RIDGING/1.25 INCH PWAT AXIS BUILDS IN FROM THE
WEST. GUIDANCE CONTINUES TO DEPICT STRONG LOW LEVEL CONVERGENCE WITH
ASSOCIATED LOW LEVEL TROUGH THURSDAY EVENING...WITH ADDITIONAL
SYNOPTIC SUPPORT FROM A 100 KNOT UPPER JET STREAK NOSING INTO THE MD
MS VALLEY. GIVEN ABOVE FACTORS...AND FAIRLY CONSISTENT RUN TO RUN
SIGNAL...HAVE NUDGED UP TO CATEGORICAL POPS OVERSPREADING THE AREA
WEST TO EAST THURSDAY EVENING. DURATION OF PRECIP SHOULD BE
RELATIVELY SHORT HOWEVER AS PROGRESSIVE NATURE OF THIS SYSTEM ALLOWS
LOW LEVEL MOIST TONGUE TO SHIFT EAST OF THE AREA DURING THE
OVERNIGHT HOURS. STRONG LOW LEVEL CONVERGENCE COULD YIELD SOME
IMPRESSIVE RAINFALL RATES FOR A TIME...BUT ONCE AGAIN PROGRESSIVE
NATURE OF SYSTEM SHOULD LIMIT RAINFALL AMOUNTS TO 0.25-0.50 INCHES.
WILL CONTINUE TO LIMIT TS POTENTIAL TO CHANCE AT THIS TIME...WITH
NAM/GFS BUFFER SOUNDINGS CONTINUING TO DEPICT MEAGER INSTABILITY
PROFILES.

WEAK COLD ADVECTION TO ENSUE FOR LATE THURSDAY NIGHT/FRIDAY MORNING
BEHIND SFC FRONT...ALTHOUGH DEEPER POST-FRONTAL MIXING ON FRIDAY
SHOULD OFFSET SLIGHTLY COOLER LOW LEVEL PROFILES...AND THEN
SOME...WITH HIGHS EXPECTED IN THE UPPER 60S TO POSSIBLY LOWER 70S. A
MUCH DRIER AIR MASS WILL OVERSPREAD THE AREA HOWEVER...AIDED BY
STRONG COLUMN LARGE SCALE SUBSIDENCE. MID LEVEL COLD POCKET
ADVECTING INTO THE SOUTHERN GREAT LAKES FOR FRIDAY SHOULD LEND TO
STEEP LOW/MID LEVEL LAPSE RATES...WITH MAIN UNCERTAINTY IN ANY
LOW END PRECIP CHANCE ON DEPTH OF MIXED LAYER AND BOUNDARY LAYER
MOISTURE. SOME WEAK SYNOPTIC FORCING MAY EXIST ACROSS THE FAR NORTH
ALONG SOUTHERN PERIPHERY OF GREAT LAKES DPVA...BUT WILL KEEP
FORECAST DRY AT THIS POINT WITH EXPECTATION OF ONLY AN INCREASE IN
HIGHER BASED CU FRIDAY AFTERNOON WITH SOME VERTICAL EXTENT GIVEN MID
LEVEL LAPSE RATES. SOME LOW END ISOLD SHRA POTENTIAL MAY EXTEND
SOUTHWARD ACROSS THE REMAINDER OF THE AREA THROUGH FRIDAY EVENING AS
STRONGER 850-700 HPA FRONTOGENESIS SHIFTS SOUTHWARD IN ASSOCIATION
WITH SECONDARY FRONTAL BOUNDARY. GIVEN EXPECTED DEPTH TO MIXED LAYER
FRIDAY DID GO AHEAD AND DROP AFTERNOON DEW PTS A FEW DEGREES CLOSER
TO MOS VALUES WHICH COULD POSE SOME FIRE WEATHER CONCERNS GIVEN
BREEZY/WINDY CONDITIONS. HOWEVER...PROBABLE RAINFALL THURSDAY NIGHT
AND WET SOILS SHOULD TEND TO MITIGATE THIS CONCERN.

MUCH COOLER DAY SHAPING UP FOR SATURDAY...PARTICULARLY ACROSS THE
FAR NORTHWEST WHERE SOUTH CENTRAL CANADIAN HIGH PRESSURE PROVIDES
ONSHORE FLOW...LIKELY KEEPING AFTERNOON HIGHS IN THE MID-UPPER 40S.
MID/UPPER LEVEL FLOW PATTERN TO BECOME LESS PROGRESSIVE/BLOCKY BY
LATER THIS WEEKEND WHICH WILL ALLOW MID LEVEL RIDGING TO MAINTAIN
ITS GRIP ON THE REGION THROUGH MUCH OF THE WEEKEND. WITH MAIN UPPER
TROUGH CUTTING OFF ACROSS THE CENTRAL PLAINS BY LATE
WEEKEND...SOUTHEAST LOW LEVEL FLOW SHOULD TEND TO DELAY SIGNIFICANT
MOISTURE RETURN UNTIL VERY LATE WEEKEND/OR EARLY NEXT WEEK
PARTICULARLY ACROSS THE FAR NORTHEAST. THUS HAVE LOWERED CR ALLBLEND
POPS ACROSS THE NORTHEAST...AND HAVE PUT MORE WEIGHT ON PREVIOUS
FORECAST WITH MAINTENANCE OF LOWER POPS THROUGH SUNDAY AFTERNOON
BEFORE DEEPER MOISTURE ONCE AGAIN ADVECTS INTO THE AREA.

THE LATE SUNDAY THROUGH TUESDAY PERIOD STILL LOOKS TO BE UNSETTLED
AS BROAD UPPER LEVEL NEGATIVE HEIGHT ANOMALY SHOULD PERSIST ACROSS
THE LOWER/MID MS VALLEY WITH OCCLUDED SYSTEM STALLING ACROSS THE
REGION. WHILE SYSTEM WILL BE VERTICALLY STACKED TOWARD THE END OF
THE PERIOD...PRECIP CHANCES TO PERSIST THROUGH THE MIDDLE OF NEXT
WEEK WITH LOCAL AREA POSSIBLY BECOMING POSITIONED IN FAVORABLE FGEN
REGION NORTH OF THE MID LEVEL HEIGHT MINIMUM. WEAK THERMAL RIDGE
SHOULD BE CONTINUE TO WRAP BACK INTO THE LOCAL AREA THROUGH THE END
OF THE PERIOD...BUT INFLUENCES OF CLOUDS/PRECIP SHOULD KEEP TEMPS
BELOW NORMAL FOR MON/TUE.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 130 AM EDT WED APR 23 2014

VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AS APPROACHING
MIDLEVEL RIDGE AXIS ENSURES A DRY/SUBSIDENT ENVIRONMENT THROUGH
MOST OF THE DAY. GRADUAL TOP-DOWN SATURATION EXPECTED LATER TODAY
THOUGH AS WAA SLOWLY INCREASES AHEAD OF NEXT TROUGH. A FEW
SPRINKLES ARE POSSIBLE AT KSBN TOWARD THE END OF THE PERIOD BUT
VERY DRY CONDITIONS IN THE LOWER LEVELS WILL LIMIT RAINFALL
POTENTIAL AND KEEP CEILINGS WELL ABOVE 3 KFT.

&&

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

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...MARSILI
AVIATION...AGD


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 KIND 230737
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
337 AM EDT WED APR 23 2014

.UPDATE...

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

&&

.SYNOPSIS...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH PRESSURE WILL KEEP THE WEATHER QUIET THROUGH EARLY THURSDAY. A
FRONTAL SYSTEM WILL MOVE THROUGH THE AREA LATE THURSDAY INTO
THURSDAY NIGHT...WITH THE POTENTIAL FOR WIDESPREAD SHOWERS AND
SCATTERED THUNDERSTORMS. DRY WEATHER WILL QUICKLY RETURN UNTIL LATE
IN THE WEEKEND WHEN A STACKED CLOSED LOW DRIFTS EASTWARD INTO THE
REGION...REMAINING IN THE REGION THROUGH THE REMAINDER OF THE
FORECAST PERIOD AND BRINGING REPEATED CHANCES FOR SHOWERS AND
PERHAPS A STORM OR TWO...ALONG WITH SOMEWHAT DREARY CONDITIONS.

&&

.NEAR TERM /TODAY/...
ISSUED AT 337 AM EDT WED APR 23 2014

AFTER STARTING OUT COOL...EXPECT AMPLE SUNSHINE TO HELP TEMPS RISE
TO NEAR 60 IN THE NORTH...AND THE MID TO UPPER 60S SOUTH. THIS IS
NEAR TO SLIGHTLY ABOVE A MOS BLEND...AS RAW MODEL TEMPS LOOKED FAR
TOO COLD BASED ON 850 TEMPS AND LOW LEVEL THICKNESSES. MAY SEE A BIT
OF AN INCREASE IN HIGH CLOUD LATE TODAY...BUT LIKELY TOO LATE TO
HAVE A SIGNIFICANT IMPACT ON TEMPS.

WINDS HAVE STAYED UP MUCH OF THE NIGHT AND KEPT TEMPS FROM BOTTOMING
OUT COMPLETELY. MAY HAVE TO CARRY PATCHY FROST FOR AN HOUR OR TWO
THIS MORNING ESPECIALLY FOR SHELTERED AREAS...BUT THAT WILL BE ABOUT
IT.

&&

.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
ISSUED AT 337 AM EDT WED APR 23 2014

HIGH WILL KEEP WEATHER QUIET THROUGH AT LEAST EARLY THURSDAY. SOME
GUIDANCE CONTINUES TO WANT TO DEVELOP PRECIP ACROSS THE NORTH
TONIGHT ASSOCIATED WITH AN AREA OF MIDLEVEL FRONTOGENESIS...BUT
AMPLE DRY AIR IN THE LOW LEVELS CONTINUES TO SUGGEST THIS IS
OVERDONE.

SOME ADDITIONAL MODEL DISCREPANCIES HAVE CREPT IN BETWEEN THE OLDER
EURO AND THE NEW GFS ON FRONTAL TIMING THURSDAY INTO THURSDAY
NIGHT...BUT FOR NOW WILL CONTINUE WITH WHAT HAS BEEN THE MOST
CONSISTENT SCENARIO THE LAST SEVERAL DAYS...WITH PRECIP INTO THE
AREA NO EARLIER THAN THURSDAY AFTERNOON IN THE WEST...AND ACROSS THE
ENTIRE AREA THURSDAY EVENING. ALTHOUGH SURFACE BASED INSTABILITY IS
MINIMAL...K INDEX VALUES CONTINUE TO SUGGEST THUNDER IS A GOOD
POSSIBILITY AND WILL CARRY SCATTERED THUNDERSTORMS THURSDAY EVENING.
A STRONG STORM OR TWO CANNOT BE ENTIRELY RULED OUT...BUT WIDESPREAD
SEVERE THREAT DOES NOT APPEAR IN THE CARDS...AND INDEED LATEST
CONVECTIVE OUTLOOK SHIFTS THE THREAT FOR THE DAY FURTHER
SOUTHWEST...WHICH APPEARS REASONABLE.

ON TEMPS...MOS BLEND OR SLIGHTLY ABOVE LOOKS BEST FOR MOST PERIODS
AS RAW MODEL NUMBERS CONTINUE TO LOOK TOO COOL...SIGNIFICANTLY SO IN
SOME PERIODS...BASED ON LOW LEVEL THERMAL PROGS.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR THE 230600Z TAFS/...
ISSUED AT 1103 PM EDT TUE APR 22 2014

VFR CONDITIONS ARE EXPECTED TO CONTINUE.

HIGH PRESSURE OVER THE WESTERN GREAT LAKES AND UPPER MIDWEST WILL
CONTINUE TO SLOWLY BUILD EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY DURING THIS PERIOD. TIME HEIGHT SECTIONS AND FORECAST
SOUNDINGS REMAIN VERY DRY...AMID SUBSIDENCE ASSOCIATED WITH THE
PASSING HIGH PRESSURE SYSTEM.

HIGH CLOUDS ARE EXPECTED TO INCREASE AFTER 00Z THURSDAY AS A WARM
FRONT APPROACHES FROM THE WEST. DRY AIR IN PLACE AT THE LOWER
LEVELS WILL CONTINUE TO PROVIDE VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...JP

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

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






000
FXUS63 KIND 230730
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
330 AM EDT WED APR 23 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 943 PM EDT TUE APR 22 2014

CURRENT FORECAST LOOKS GOOD. WINDS STILL LOOK TO REMAIN HIGH ENOUGH
FOR LONG ENOUGH TONIGHT TO PREVENT WIDESPREAD FROST IN THE COLDEST
AREAS. WILL CONTINUE TO MENTION PATCHY FROST MOST AREAS WITH AREAS
OF FROST IN THE FAR NORTH. SHELTERED AREAS WILL HAVE THE BEST
CHANCES FOR FROST.

OTHERWISE ONLY MADE MINOR TWEAKS TO FORECAST ELEMENTS.

PREVIOUS DISCUSSION FOLLOWS...
FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 330 AM EDT WED APR 23 2014

HIGHLY AMPLIFIED BLOCKY PATTERN DEVELOPING ALOFT WITH THE KEY PLAYER
IN WEATHER THROUGHOUT THE EXTENDED BEING AN UPPER LOW WHICH WILL
DEEPEN AS IT MOVES INTO THE CENTRAL PLAINS LATE WEEKEND...BECOME
CUTOFF FROM THE MEAN FLOW...THEN MEANDER SLOWLY EAST INTO THE
EASTERN U S BY THE MIDDLE OF NEXT WEEK. THIS WILL RESULT IN AN
EXTENDED PERIOD OF UNSETTLED WEATHER ACROSS THE REGION BEGINNING
SATURDAY NIGHT AND CONTINUING THROUGH THE END OF THE EXTENDED...AND
LIKELY BEYOND.

THE PRESENCE OF THE UPPER LOW OVER THE HIGH PLAINS ON SUNDAY WILL
PROMOTE SURFACE CYCLOGENESIS IN THE CENTRAL ROCKIES...WITH THE
SURFACE WAVE EJECTING INTO WESTERN KANSAS LATE SUNDAY AND DEEPENING
AS IT DOES SO. A WARM FRONT WILL EXTEND EAST FROM THE SURFACE WAVE
INTO THE REGION WITH SCATTERED CONVECTION BECOMING INCREASING LIKELY
DURING THE SECOND HALF OF THE WEEKEND AND INTO EARLY NEXT WEEK.
WHILE 00Z MODEL GUIDANCE IN RELATIVELY GOOD AGREEMENT ON THE
LOCATION OF THE UPPER LOW AND SURFACE WAVE...THERE REMAIN
DIFFERENCES ON WHERE THE WARM FRONT EVENTUALLY SETS UP. THE ECMWF
REMAINS FURTHEST NORTH...SIMILAR TO ITS 22/12Z RUN...AND PLACES MUCH
OF THE FORECAST AREA WITHIN THE WARM SECTOR. OP GFS AND GGEM REMAIN
SOUTH CLOSER TO THE OHIO RIVER. HAVE BUMPED UP TEMPS A FEW DEGREES
FROM PREVIOUS FORECAST FOR SUNDAY THROUGH TUESDAY BUT SHOULD THE
MORE NORTHERN PLACEMENT TO THE BOUNDARY VIA THE ECMWF SOLUTION BE
REALIZED...TEMPS WILL NEED TO BE RAISED FURTHER. WILL CONTINUE TO
MONITOR.

REGARDLESS OF THE EXACT PLACEMENT OF THE FRONT...HIGH CHANCE POPS
ARE WARRANTED FROM SUNDAY THROUGH THE MIDDLE PART OF NEXT WEEK AS
THE SURFACE WAVE DRIFTS EAST INTO THE OHIO VALLEY BY THE END OF THE
PERIOD. SIGNS CONTINUE TO POINT TO THE UPPER LOW CARVING OUT A BROAD
TROUGH OVER THE EASTERN HALF OF THE COUNTRY...RESULTING IN AN
EXTENDED PERIOD OF COOL DAMP WEATHER POSSIBLY IMPACTING CENTRAL
INDIANA THROUGH THE END OF NEXT WEEK.

&&

.AVIATION /DISCUSSION FOR THE 230600Z TAFS/...

ISSUED AT 1103 PM EDT TUE APR 22 2014

VFR CONDITIONS ARE EXPECTED TO CONTINUE.

HIGH PRESSURE OVER THE WESTERN GREAT LAKES AND UPPER MIDWEST WILL
CONTINUE TO SLOWLY BUILD EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY DURING THIS PERIOD. TIME HEIGHT SECTIONS AND FORECAST
SOUNDINGS REMAIN VERY DRY...AMID SUBSIDENCE ASSOCIATED WITH THE
PASSING HIGH PRESSURE SYSTEM.

HIGH CLOUDS ARE EXPECTED TO INCREASE AFTER 00Z THURSDAY AS A WARM
FRONT APPROACHES FROM THE WEST. DRY AIR IN PLACE AT THE LOWER
LEVELS WILL CONTINUE TO PROVIDE VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/50
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...JP

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

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








000
FXUS63 KIWX 230530
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
130 AM EDT WED APR 23 2014

.SYNOPSIS...
ISSUED AT 736 PM EDT TUE APR 22 2014

COLDER AIR WILL CONTINUE TO FILTER INTO THE AREA OVERNIGHT AS HIGH
PRESSURE DEEPENS OVER THE GREAT LAKES. LOWS TONIGHT WILL DROP TO
NEAR OR BELOW THE FREEZING MARK WITH PATCHY FROST POSSIBLE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

STRONG ISENTROPIC DESCENT/LARGE SCALE SUBSIDENCE IN ADVANCE OF A
BUILDING MID LEVEL RIDGE WILL SUPPORT DRY CONDITIONS AND MAINLY
CLEAR SKIES TONIGHT INTO WEDNESDAY. GUSTY NORTHERLY WINDS WILL
QUICKLY SUBSIDE EARLY THIS EVENING WITH LOSS OF DEEPER DIURNAL
MIXING AND WEAKENING PRESSURE GRADIENT AS AN UPPER MIDWEST SFC RIDGE
BEGINS TO BUILD INTO THE LOCAL AREA. COLD/DRY CP AIRMASS AND
DECOUPLING UNDER CLEAR SKIES WILL ENSURE A CHILLY NIGHT WITH MOST
LOCATIONS DROPPING INTO THE LOW 30S. NO FROST/FREEZE HEADLINES
NEEDED WITH GROWING SEASON NOT IN FULL SWING YET...BUT DID CONTINUE
WITH A SPS GIVEN POTENTIAL FROST DAMAGE TO SENSITIVE OUTDOOR PLANTS
AND FLOWERS. TOMORROW WILL FEATURE LIGHT WINDS AND A 25-30F DIURNAL
TEMP RECOVERY UNDER HIGH PRESSURE.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

LONG TERM PERIOD WILL BEGIN WITH NEAR NORMAL TEMPERATURES WEDNESDAY
NIGHT INTO THURSDAY...AS LARGE SCALE RIDGE CENTERED OVER THE REGION
SLIDES TO THE EAST. WAA RESPONSE AHEAD OF DIGGING UPSTREAM S/W AND
DEEPENING SFC CYCLONE COULD YIELD SOME LIGHT PRECIPITATION ACROSS
WESTERN AND NORTHERN AREAS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. NARROW MID LVL FRONTOGENETIC BAND/CORRIDOR OF ISENTROPIC
ASCENT IS PROGGED TO CLIP THE NORTHWEST HALF OF THE AREA AFTER 00Z.
WHILE THE MID LVL FORCING AND MOISTURE LOOK SUFFICIENT FOR THE
DEVELOPMENT OF MEASURABLE PRECIP...LOW LEVELS LOOK EXTREMELY DRY
WITH THE ONSET OF THE FORCING...AND REMAIN FAIRLY DRY BELOW 850 MB
THROUGH THE OVERNIGHT. WILL STICK WITH THE SPRINKLE MENTION IN THE
FCST...AS COMPACT NATURE OF THE FRONTAL BAND/FORCING LOOKS TO BE
INCAPABLE OF SUFFICIENTLY SATURATING THE LOW LEVELS AND PRODUCING
MEASURABLE PRECIP.

AFTER A PLEASANT DAY ON THURSDAY...WITH NEAR TO SLIGHTLY ABOVE
NORMAL HIGH TEMPS IN THE MID TO UPPER 60S...PRECIPITATION CHANCES
WILL INCREASE LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. A
FRONTAL BOUNDARY WILL APPROACH THE REGION FROM THE WEST...AS A
MID/UPPER S/W AND SFC LOW TRACK EAST ACROSS THE GREAT LAKES REGION.
LATEST MODEL SOLUTIONS GREATLY DIFFER WITH THE HANDLING OF THIS
SYSTEM. 12Z ECMWF REMAINS FARTHER NORTH WITH THE MID/UPPER LVL
ENERGY AND 500 MB JET...WITH A SEPARATE MID/UPPER LEVEL WAVE TRACKING
FROM THE SOUTHERN PLAINS INTO THE OHIO VALLEY. THE SOUTHERN
PERIPHERY OF THE TROF AXIS REMAINS NEUTRALLY TILTED...RESULTING IN A
SLOWER SOLUTION. 12Z GFS IS FARTHER SOUTH WITH THE MID LVL WAVE AND
JET...PHASING WITH THE SOUTHERN STREAM WAVE AS IT KICKS NORTHEAST
TOWARD THE REGION. THIS PHASED SYSTEM RESULTS IN A FASTER FRONTAL
PASSAGE. RESULTING FCST SOLUTION IS A BLEND OF THE PREVIOUS FORECAST
AND THE 12Z MODEL SOLUTIONS...WEIGHTED TOWARD THE 12Z ECMWF. THIS
FCST RESULTS IN POPS HOLDING OFF UNTIL 00Z EXCEPT FOR THE FAR WEST.
HELD WITH LIKELY POPS AND CHANCE THUNDER FROM 00Z TO 06Z...ALTHOUGH
THUNDER CHANCES LOOK MARGINAL AT BEST AT THIS POINT.

FORECAST CONFIDENCE CONTINUES TO DECREASE SIGNIFICANTLY FROM THIS
WEEKEND INTO NEXT WEEK. TEMPERATURES ON FRIDAY LOOK COMPARABLE TO
THURSDAY IN THE WAKE OF THE OCCLUDED FROPA...WITH TEMPERATURES IN
THE UPPER 60S TO LOW 70S. FRIDAY NIGHT AND BEYOND...LARGE SCALE
PATTERN BECOMES SIGNIFICANTLY UNCERTAIN WITH REGARDS TO TEMPERATURES
AND PRECIPITATION.

MODELS DEPICTING A SECONDARY FRONT SHIFTING SOUTH INTO THE AREA
FRIDAY NIGHT INTO SATURDAY...AS MID/UPPER S/W AND ASSOCIATED SFC LOW
TRACKS EAST OUT OF THE GREAT LAKES TOWARD NEW ENGLAND. THIS COULD
BRING SOME LIGHT RAIN SHOWER ACTIVITY TO THE AREA FRIDAY NIGHT...AND
BELOW NORMAL TEMPERATURES ON SATURDAY THROUGH THE WEEKEND.
NORTHERLY/NORTHWEST FLOW AND STRONG CANADIAN SFC HIGH PRESSURE LOOKS
TO REINFORCE THIS BAROCLINIC ZONE JUST SOUTH OF THE AREA...AND SHARP
MID/UPPER LEVEL RIDGING TAKES HOLD ACROSS THE PLAINS IN RESPONSE TO
DIGGING WRN CONUS UPPER TROF. THIS WOULD SUPPORT PERIODIC PRECIP
CHANCES ALONG THE BAROCLINIC ZONE...WITH BELOW NORMAL TEMPS FOR THE
AREA. THIS IS THE CONSENSUS FROM THE 12Z GFS AND GEFS MEAN. THE END
OF THE 09Z SREF AND 12Z GEM SUPPORT THIS IDEA...HOWEVER THE
BAROCLINIC ZONE DEPICTED IS FARTHER NORTH THAN THE GFS/GEFS
SOLUTION. THE 12Z ECMWF REMAINS THE FARTHEST NORTH WITH THE LATE
WEEK S/W...AND KEEPS THE SECONDARY FRONT UP ACROSS THE NORTHERN
GREAT LAKES THROUGH THE WEEKEND. THIS WOULD PLACE THE AREA IN THE
WARM SECTOR OF THIS SYSTEM...LIKELY YIELDING ABOVE NORMAL
TEMPERATURES FROM SATURDAY THROUGH MONDAY.

WITH THE WIDE RANGE OF SOLUTIONS...NO MAJOR CHANGES TO THE FORECAST
REGARDING TEMPS AND PRECIP AFTER FRIDAY NIGHT. HOWEVER...DID ADJUST
SATURDAY HIGH TEMPERATURES UP A FEW DEGREES...ESPECIALLY SOUTH...AS
MODELS AS A WHOLE ARE TRENDING TOWARD A SLOWER SOUTHWARD PUSH OF THE
SECONDARY FRONT...ALONG WITH DECREASING CONFIDENCE IN THE GEFS
MEAN...WITH 850 MB STANDARD DEVIATIONS AROUND 4C ACROSS THE LOWER
GREAT LAKES DURING THIS TIME PERIOD.

TOWARD THE END OF THE FCST PERIOD AND JUST BEYOND...MODELS STILL
INDICATE A MORE BLOCKED PATTERN ACROSS THE CONUS. LARGE CUTOFF LOW
LOOKS TO DEVELOP ACROSS THE CENTRAL CONUS BY MIDWEEK...AND SLOWLY
MEANDER ACROSS THE EASTERN CONUS. MEANWHILE...ANOTHER LARGE CUTOFF
LOW DEVELOPS ACROSS THE EASTERN PACIFIC/OFF THE CONUS WEST
COAST...WITH AN EXTREMELY AMPLIFIED WRN CONUS RIDGE. THIS BLOCK
WOULD PROVIDED AN EXTENDED PERIOD OF BELOW NORMAL TEMPS FROM MIDWEEK
THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND...ALONG WITH PERIODIC
PRECIPITATION CHANCES...FOR MUCH OF THE EASTERN CONUS..INCLUDING OUR
FORECAST AREA.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 130 AM EDT WED APR 23 2014

VFR CONDITIONS WILL PERSIST THROUGH THE PERIOD AS APPROACHING
MIDLEVEL RIDGE AXIS ENSURES A DRY/SUBSIDENT ENVIRONMENT THROUGH
MOST OF THE DAY. GRADUAL TOP-DOWN SATURATION EXPECTED LATER TODAY
THOUGH AS WAA SLOWLY INCREASES AHEAD OF NEXT TROUGH. A FEW
SPRINKLES ARE POSSIBLE AT KSBN TOWARD THE END OF THE PERIOD BUT
VERY DRY CONDITIONS IN THE LOWER LEVELS WILL LIMIT RAINFALL
POTENTIAL AND KEEP CEILINGS WELL ABOVE 3 KFT.

&&

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

$$

SYNOPSIS...CEO
SHORT TERM...STEINWEDEL
LONG TERM...NG
AVIATION...AGD


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000
FXUS63 KIND 230440
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1240 AM EDT WED APR 23 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 943 PM EDT TUE APR 22 2014

CURRENT FORECAST LOOKS GOOD. WINDS STILL LOOK TO REMAIN HIGH ENOUGH
FOR LONG ENOUGH TONIGHT TO PREVENT WIDESPREAD FROST IN THE COLDEST
AREAS. WILL CONTINUE TO MENTION PATCHY FROST MOST AREAS WITH AREAS
OF FROST IN THE FAR NORTH. SHELTERED AREAS WILL HAVE THE BEST
CHANCES FOR FROST.

OTHERWISE ONLY MADE MINOR TWEAKS TO FORECAST ELEMENTS.

PREVIOUS DISCUSSION FOLLOWS...
FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 230600Z TAFS/...

ISSUED AT 1103 PM EDT TUE APR 22 2014

VFR CONDITIONS ARE EXPECTED TO CONTINUE.

HIGH PRESSURE OVER THE WESTERN GREAT LAKES AND UPPER MIDWEST WILL
CONTINUE TO SLOWLY BUILD EAST ACROSS THE GREAT LAKES AND OHIO
VALLEY DURING THIS PERIOD. TIME HEIGHT SECTIONS AND FORECAST
SOUNDINGS REMAIN VERY DRY...AMID SUBSIDENCE ASSOCIATED WITH THE
PASSING HIGH PRESSURE SYSTEM.

HIGH CLOUDS ARE EXPECTED TO INCREASE AFTER 00Z THURSDAY AS A WARM
FRONT APPROACHES FROM THE WEST. DRY AIR IN PLACE AT THE LOWER
LEVELS WILL CONTINUE TO PROVIDE VFR CONDITIONS.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/50
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JP

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 230230
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1030 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 943 PM EDT TUE APR 22 2014

CURRENT FORECAST LOOKS GOOD. WINDS STILL LOOK TO REMAIN HIGH ENOUGH
FOR LONG ENOUGH TONIGHT TO PREVENT WIDESPREAD FROST IN THE COLDEST
AREAS. WILL CONTINUE TO MENTION PATCHY FROST MOST AREAS WITH AREAS
OF FROST IN THE FAR NORTH. SHELTERED AREAS WILL HAVE THE BEST
CHANCES FOR FROST.

OTHERWISE ONLY MADE MINOR TWEAKS TO FORECAST ELEMENTS.

PREVIOUS DISCUSSION FOLLOWS...
FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 230300Z TAF UPDATE/...

ISSUED AT 1030 PM EDT TUE APR 22 2014

ONLY MADE MINOR ADJUSTMENT TO WINDS.

PREVIOUS DISCUSSION FOLLOWS...

VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD.

HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD EAST INTO THE
GREAT LAKES AND INDIANA DURING THIS PERIOD. TIME HEIGHT SECTIONS
AND FORECAST SOUNDINGS SHOW A DRY COLUMN. CONVECTIVE TEMPS ARE
AROUND 90. THUS JUST SOME PASSING CI WILL BE EXPECTED IN THE QUICK
NORTHWEST FLOW ALOFT.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP/50
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JP/50

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

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






000
FXUS63 KIND 230143
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
943 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /REST OF TONIGHT/...

ISSUED AT 943 PM EDT TUE APR 22 2014

CURRENT FORECAST LOOKS GOOD. WINDS STILL LOOK TO REMAIN HIGH ENOUGH
FOR LONG ENOUGH TONIGHT TO PREVENT WIDESPREAD FROST IN THE COLDEST
AREAS. WILL CONTINUE TO MENTION PATCHY FROST MOST AREAS WITH AREAS
OF FROST IN THE FAR NORTH. SHELTERED AREAS WILL HAVE THE BEST
CHANCES FOR FROST.

OTHERWISE ONLY MADE MINOR TWEAKS TO FORECAST ELEMENTS.

PREVIOUS DISCUSSION FOLLOWS...
FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.

&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 230000Z TAFS/...

ISSUED AT 708 PM EDT TUE APR 22 2014

VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD.

HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD EAST INTO THE
GREAT LAKES AND INDIANA DURING THIS PERIOD. TIME HEIGHT SECTIONS
AND FORECAST SOUNDINGS SHOW A DRY COLUMN. CONVECTIVE TEMPS ARE
AROUND 90. THUS JUST SOME PASSING CI WILL BE EXPECTED IN THE QUICK
NORTHWEST FLOW ALOFT.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP/50
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JP

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

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






000
FXUS63 KIWX 222337
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
737 PM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 736 PM EDT TUE APR 22 2014

COLDER AIR WILL CONTINUE TO FILTER INTO THE AREA OVERNIGHT AS HIGH
PRESSURE DEEPENS OVER THE GREAT LAKES. LOWS TONIGHT WILL DROP TO
NEAR OR BELOW THE FREEZING MARK WITH PATCHY FROST POSSIBLE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

STRONG ISENTROPIC DESCENT/LARGE SCALE SUBSIDENCE IN ADVANCE OF A
BUILDING MID LEVEL RIDGE WILL SUPPORT DRY CONDITIONS AND MAINLY
CLEAR SKIES TONIGHT INTO WEDNESDAY. GUSTY NORTHERLY WINDS WILL
QUICKLY SUBSIDE EARLY THIS EVENING WITH LOSS OF DEEPER DIURNAL
MIXING AND WEAKENING PRESSURE GRADIENT AS AN UPPER MIDWEST SFC RIDGE
BEGINS TO BUILD INTO THE LOCAL AREA. COLD/DRY CP AIRMASS AND
DECOUPLING UNDER CLEAR SKIES WILL ENSURE A CHILLY NIGHT WITH MOST
LOCATIONS DROPPING INTO THE LOW 30S. NO FROST/FREEZE HEADLINES
NEEDED WITH GROWING SEASON NOT IN FULL SWING YET...BUT DID CONTINUE
WITH A SPS GIVEN POTENTIAL FROST DAMAGE TO SENSITIVE OUTDOOR PLANTS
AND FLOWERS. TOMORROW WILL FEATURE LIGHT WINDS AND A 25-30F DIURNAL
TEMP RECOVERY UNDER HIGH PRESSURE.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

LONG TERM PERIOD WILL BEGIN WITH NEAR NORMAL TEMPERATURES WEDNESDAY
NIGHT INTO THURSDAY...AS LARGE SCALE RIDGE CENTERED OVER THE REGION
SLIDES TO THE EAST. WAA RESPONSE AHEAD OF DIGGING UPSTREAM S/W AND
DEEPENING SFC CYCLONE COULD YIELD SOME LIGHT PRECIPITATION ACROSS
WESTERN AND NORTHERN AREAS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. NARROW MID LVL FRONTOGENETIC BAND/CORRIDOR OF ISENTROPIC
ASCENT IS PROGGED TO CLIP THE NORTHWEST HALF OF THE AREA AFTER 00Z.
WHILE THE MID LVL FORCING AND MOISTURE LOOK SUFFICIENT FOR THE
DEVELOPMENT OF MEASURABLE PRECIP...LOW LEVELS LOOK EXTREMELY DRY
WITH THE ONSET OF THE FORCING...AND REMAIN FAIRLY DRY BELOW 850 MB
THROUGH THE OVERNIGHT. WILL STICK WITH THE SPRINKLE MENTION IN THE
FCST...AS COMPACT NATURE OF THE FRONTAL BAND/FORCING LOOKS TO BE
INCAPABLE OF SUFFICIENTLY SATURATING THE LOW LEVELS AND PRODUCING
MEASURABLE PRECIP.

AFTER A PLEASANT DAY ON THURSDAY...WITH NEAR TO SLIGHTLY ABOVE
NORMAL HIGH TEMPS IN THE MID TO UPPER 60S...PRECIPITATION CHANCES
WILL INCREASE LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. A
FRONTAL BOUNDARY WILL APPROACH THE REGION FROM THE WEST...AS A
MID/UPPER S/W AND SFC LOW TRACK EAST ACROSS THE GREAT LAKES REGION.
LATEST MODEL SOLUTIONS GREATLY DIFFER WITH THE HANDLING OF THIS
SYSTEM. 12Z ECMWF REMAINS FARTHER NORTH WITH THE MID/UPPER LVL
ENERGY AND 500 MB JET...WITH A SEPARATE MID/UPPER LEVEL WAVE TRACKING
FROM THE SOUTHERN PLAINS INTO THE OHIO VALLEY. THE SOUTHERN
PERIPHERY OF THE TROF AXIS REMAINS NEUTRALLY TILTED...RESULTING IN A
SLOWER SOLUTION. 12Z GFS IS FARTHER SOUTH WITH THE MID LVL WAVE AND
JET...PHASING WITH THE SOUTHERN STREAM WAVE AS IT KICKS NORTHEAST
TOWARD THE REGION. THIS PHASED SYSTEM RESULTS IN A FASTER FRONTAL
PASSAGE. RESULTING FCST SOLUTION IS A BLEND OF THE PREVIOUS FORECAST
AND THE 12Z MODEL SOLUTIONS...WEIGHTED TOWARD THE 12Z ECMWF. THIS
FCST RESULTS IN POPS HOLDING OFF UNTIL 00Z EXCEPT FOR THE FAR WEST.
HELD WITH LIKELY POPS AND CHANCE THUNDER FROM 00Z TO 06Z...ALTHOUGH
THUNDER CHANCES LOOK MARGINAL AT BEST AT THIS POINT.

FORECAST CONFIDENCE CONTINUES TO DECREASE SIGNIFICANTLY FROM THIS
WEEKEND INTO NEXT WEEK. TEMPERATURES ON FRIDAY LOOK COMPARABLE TO
THURSDAY IN THE WAKE OF THE OCCLUDED FROPA...WITH TEMPERATURES IN
THE UPPER 60S TO LOW 70S. FRIDAY NIGHT AND BEYOND...LARGE SCALE
PATTERN BECOMES SIGNIFICANTLY UNCERTAIN WITH REGARDS TO TEMPERATURES
AND PRECIPITATION.

MODELS DEPICTING A SECONDARY FRONT SHIFTING SOUTH INTO THE AREA
FRIDAY NIGHT INTO SATURDAY...AS MID/UPPER S/W AND ASSOCIATED SFC LOW
TRACKS EAST OUT OF THE GREAT LAKES TOWARD NEW ENGLAND. THIS COULD
BRING SOME LIGHT RAIN SHOWER ACTIVITY TO THE AREA FRIDAY NIGHT...AND
BELOW NORMAL TEMPERATURES ON SATURDAY THROUGH THE WEEKEND.
NORTHERLY/NORTHWEST FLOW AND STRONG CANADIAN SFC HIGH PRESSURE LOOKS
TO REINFORCE THIS BAROCLINIC ZONE JUST SOUTH OF THE AREA...AND SHARP
MID/UPPER LEVEL RIDGING TAKES HOLD ACROSS THE PLAINS IN RESPONSE TO
DIGGING WRN CONUS UPPER TROF. THIS WOULD SUPPORT PERIODIC PRECIP
CHANCES ALONG THE BAROCLINIC ZONE...WITH BELOW NORMAL TEMPS FOR THE
AREA. THIS IS THE CONSENSUS FROM THE 12Z GFS AND GEFS MEAN. THE END
OF THE 09Z SREF AND 12Z GEM SUPPORT THIS IDEA...HOWEVER THE
BAROCLINIC ZONE DEPICTED IS FARTHER NORTH THAN THE GFS/GEFS
SOLUTION. THE 12Z ECMWF REMAINS THE FARTHEST NORTH WITH THE LATE
WEEK S/W...AND KEEPS THE SECONDARY FRONT UP ACROSS THE NORTHERN
GREAT LAKES THROUGH THE WEEKEND. THIS WOULD PLACE THE AREA IN THE
WARM SECTOR OF THIS SYSTEM...LIKELY YIELDING ABOVE NORMAL
TEMPERATURES FROM SATURDAY THROUGH MONDAY.

WITH THE WIDE RANGE OF SOLUTIONS...NO MAJOR CHANGES TO THE FORECAST
REGARDING TEMPS AND PRECIP AFTER FRIDAY NIGHT. HOWEVER...DID ADJUST
SATURDAY HIGH TEMPERATURES UP A FEW DEGREES...ESPECIALLY SOUTH...AS
MODELS AS A WHOLE ARE TRENDING TOWARD A SLOWER SOUTHWARD PUSH OF THE
SECONDARY FRONT...ALONG WITH DECREASING CONFIDENCE IN THE GEFS
MEAN...WITH 850 MB STANDARD DEVIATIONS AROUND 4C ACROSS THE LOWER
GREAT LAKES DURING THIS TIME PERIOD.

TOWARD THE END OF THE FCST PERIOD AND JUST BEYOND...MODELS STILL
INDICATE A MORE BLOCKED PATTERN ACROSS THE CONUS. LARGE CUTOFF LOW
LOOKS TO DEVELOP ACROSS THE CENTRAL CONUS BY MIDWEEK...AND SLOWLY
MEANDER ACROSS THE EASTERN CONUS. MEANWHILE...ANOTHER LARGE CUTOFF
LOW DEVELOPS ACROSS THE EASTERN PACIFIC/OFF THE CONUS WEST
COAST...WITH AN EXTREMELY AMPLIFIED WRN CONUS RIDGE. THIS BLOCK
WOULD PROVIDED AN EXTENDED PERIOD OF BELOW NORMAL TEMPS FROM MIDWEEK
THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND...ALONG WITH PERIODIC
PRECIPITATION CHANCES...FOR MUCH OF THE EASTERN CONUS..INCLUDING OUR
FORECAST AREA.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 736 PM EDT TUE APR 22 2014

SFC RIDGE WILL DEEPEN FURTHER THROUGH THE WRN LAKES NR TERM AND
RESULT IN VFR CONDS PERSISTING THROUGH THE PD. OTRWS CURRENT GUSTY
N/NW GRADIENT FLW WILL COLLAPSE THROUGH SUNSET.

&&

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

$$

SYNOPSIS...CEO
SHORT TERM...STEINWEDEL
LONG TERM...NG
AVIATION...T


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000
FXUS63 KIND 222316
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
716 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.


&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 230000Z TAFS/...

ISSUED AT 708 PM EDT TUE APR 22 2014

VFR CONDITIONS ARE EXPECTED THIS TAF PERIOD.

HIGH PRESSURE OVER THE CENTRAL PLAINS WILL BUILD EAST INTO THE
GREAT LAKES AND INDIANA DURING THIS PERIOD. TIME HEIGHT SECTIONS
AND FORECAST SOUNDINGS SHOW A DRY COLUMN. CONVECTIVE TEMPS ARE
AROUND 90. THUS JUST SOME PASSING CI WILL BE EXPECTED IN THE QUICK
NORTHWEST FLOW ALOFT.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JP

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

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






000
FXUS63 KIND 222025
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
425 PM EDT TUE APR 22 2014

.UPDATE...
AVIATION SECTIONS UPDATED.

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.


&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR THE 222100Z IND TAF UPDATE/...

VFR CONDITIONS WILL CONTINUE AS HIGH PRESSURE BUILDS ACROSS THE
AREA. ONGOING TAFS ARE IN GOOD SHAPE.

PREVIOUS DISCUSSION BELOW

/DISCUSSION FOR 221800Z TAF ISSUANCE/...
ISSUED AT 1240 PM EDT TUE APR 22 2014

VFR THROUGH THE PERIOD.

WIND GUSTS UP TO 25 KNOTS THIS AFTERNOON...BUT WINDS WILL BECOME
LIGHTER TONIGHT AND TUESDAY AS HIGH PRESSURE RIDGE OVER THE UPPER
MIDWEST DRIFTS EAST INTO OUR REGION.

EXPECT CLEAR SKIES THIS AFTERNOON AND TONIGHT. BUT WOULD NOT RULE
OUT A FEW CU SOME AREAS THIS AFTERNOON.  ON TUESDAY MODEL SOUNDINGS
INDICATE INCREASING HIGH CLOUDS WITH SOME MID CLOUDS BY MID OR LATE
AFTERNOON.


&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JH/JP

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

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










000
FXUS63 KIND 221954
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
354 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 351 PM EDT TUE APR 22 2014

HIGH PRESSURE WILL KEEP DRY WEATHER IN THE FORECAST INTO
THURSDAY...BUT THE MOSTLY CLEAR SKIES AND FAIRLY LIGHT WINDS COULD
LEAD TO FROST TONIGHT. THURSDAY EVENING A COLD FRONT WILL APPROACH
FROM THE WEST AND BRING RAIN AND CHANCES FOR THUNDERSTORMS TO THE
AREA ESPECIALLY DURING THURSDAY NIGHT. MOSTLY DRY WEATHER IS
EXPECTED FRIDAY THROUGH SATURDAY...BUT BY SATURDAY NIGHT AN UPPER
LOW REACHING THE PLAINS AND SLOWLY MOVING EASTWARD WILL BRING
CHANCES FOR RAIN AND A FEW THUNDERSTORMS ON AND OFF TO THE AREA
THROUGH THE REST OF THE PERIOD AS WELL AS BELOW NORMAL HIGHS.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON TEMPERATURES AND POTENTIAL FOR FROST FORMATION.
HIGH PRESSURE CONTINUES TO BUILD OVER THE AREA WITH THE CENTER OF
THE SURFACE HIGH OVER MINNESOTA. THE CENTER OF THE HIGH WILL REMAIN
TO THE NORTHWEST OF THE AREA THROUGH THE NIGHT...KEEPING THE
PRESSURE GRADIENT ACROSS THE AREA FROM COMPLETELY SLACKENING AND
THUS KEEPING THE WINDS FROM DROPPING TO CALM. COULD SEE SOME WISPY
CIRRUS OVERTOPPING THE UPPER RIDGE AXIS BUT THIS SHOULD NOT
SERIOUSLY INHIBIT COOLING. WITH THE WIND THOUGH WENT WITH THE WARMER
MAV NUMBERS IN THE LOW 30S IN THE NORTH TO AROUND 40 IN THE
SOUTHWEST. COULD SEE SOME PATCHY FROST AND EVEN PERHAPS AREAS OF
FROST IN THE FAR NORTHERN COUNTIES BUT THE EXTENT OF THE FROST WILL
DEPEND GREATLY ON THE WINDS. THUS WITH LOW CONFIDENCE IN WIDESPREAD
FROST AND AFTER COORDINATION WITH SURROUNDING OFFICES WILL ISSUE AN
SPS FOR MOST OF THE FORECAST AREA FOR FROST BUT WILL NOT GO WITH ANY
HEADLINE.


&&

.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...

ISSUED AT 351 PM EDT TUE APR 22 2014

FORECAST FOCUS IS ON POPS/TIMING OF THURSDAY/THURSDAY NIGHT SYSTEM.
MODELS ARE IN GOOD AGREEMENT AND GENERALLY USED A MOS CONSENSUS.
QUIET WEATHER WILL BE IN PLACE FOR WEDNESDAY AND WEDNESDAY NIGHT
UNDER STRONG UPPER RIDGING. WHILE MODELS ARE TRYING TO DEVELOP SOME
MINOR QPF ALONG A BUILDING WARM FRONT WEDNESDAY NIGHT OVER THE TOP
OF THE UPPER RIDGE...AT THIS TIME THINK THE RIDGE WILL BE TOO STRONG
TO ALLOW ANY RAIN TO MOVE THIS FAR SOUTH. THURSDAY MODELS ARE IN
GOOD AGREEMENT IN KEEPING THE AREA DRY THROUGH 18Z. THIS SET OF RUNS
IS A LITTLE SLOWER WITH THE PROGRESSION OF THE COLD FRONT AND THUS
LOWERED POPS TO DRY IN THE EAST AND KEPT JUST CHANCE GOING IN THE
WEST UNTIL AFTER 0Z. GOOD AGREEMENT ON A LOW LEVEL JET ENHANCING
UPWARD MOTION AHEAD OF THE FRONT BETWEEN 0 AND 6Z FRIDAY AND
MAXIMIZED POPS AT HIGH LIKELIES THEN. WITH WEAK INSTABILITY BUT
STRONG FORCING INCLUDED A CHANCE FOR THUNDER UNTIL 6Z. STILL IN THE
DAY 3 SEE TEXT...AND WITH THE TIMING OF THE FRONTAL PASSAGE AT THIS
TIME AND VERY LITTLE INSTABILITY AVAILABLE NOT ANTICIPATING A SLIGHT
RISK UNLESS NEW RUNS CHANGE THE TIMING. AFTER THAT ALL INSTABILITY
WAS GONE AND THE FRONT WAS JUST ABOUT EAST OF THE AREA. DRY WEATHER
BUILDS BACK IN FOR FRIDAY.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/...
ISSUED AT 1240 PM EDT TUE APR 22 2014

VFR THROUGH THE PERIOD.

WIND GUSTS UP TO 25 KNOTS THIS AFTERNOON...BUT WINDS WILL BECOME
LIGHTER TONIGHT AND TUESDAY AS HIGH PRESSURE RIDGE OVER THE UPPER
MIDWEST DRIFTS EAST INTO OUR REGION.

EXPECT CLEAR SKIES THIS AFTERNOON AND TONIGHT. BUT WOULD NOT RULE
OUT A FEW CU SOME AREAS THIS AFTERNOON.  ON TUESDAY MODEL SOUNDINGS
INDICATE INCREASING HIGH CLOUDS WITH SOME MID CLOUDS BY MID OR LATE
AFTERNOON.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP
SHORT TERM...CP
LONG TERM....JEH
AVIATION...JH

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

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






000
FXUS63 KIWX 221943
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
343 PM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 1203 PM EDT TUE APR 22 2014

COOLER AIR WILL CONTINUE TO FILTER INTO THE AREA THIS AFTERNOON AND
TONIGHT IN THE WAKE OF A DEPARTING COLD FRONT. GUSTY WINDS UP TO
30 MPH ARE ALSO POSSIBLE. HIGHS THIS AFTERNOON WILL GENERALLY BE
IN THE UPPER 40S TO 50S. LOWS TONIGHT WILL DROP TO NEAR OR BELOW
THE FREEZING MARK WITH AREAS OF FROST POSSIBLE.

&&

.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

STRONG ISENTROPIC DESCENT/LARGE SCALE SUBSIDENCE IN ADVANCE OF A
BUILDING MID LEVEL RIDGE WILL SUPPORT DRY CONDITIONS AND MAINLY
CLEAR SKIES TONIGHT INTO WEDNESDAY. GUSTY NORTHERLY WINDS WILL
QUICKLY SUBSIDE EARLY THIS EVENING WITH LOSS OF DEEPER DIURNAL
MIXING AND WEAKENING PRESSURE GRADIENT AS AN UPPER MIDWEST SFC RIDGE
BEGINS TO BUILD INTO THE LOCAL AREA. COLD/DRY CP AIRMASS AND
DECOUPLING UNDER CLEAR SKIES WILL ENSURE A CHILLY NIGHT WITH MOST
LOCATIONS DROPPING INTO THE LOW 30S. NO FROST/FREEZE HEADLINES
NEEDED WITH GROWING SEASON NOT IN FULL SWING YET...BUT DID CONTINUE
WITH A SPS GIVEN POTENTIAL FROST DAMAGE TO SENSITIVE OUTDOOR PLANTS
AND FLOWERS. TOMORROW WILL FEATURE LIGHT WINDS AND A 25-30F DIURNAL
TEMP RECOVERY UNDER HIGH PRESSURE.

&&

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 PM EDT TUE APR 22 2014

LONG TERM PERIOD WILL BEGIN WITH NEAR NORMAL TEMPERATURES WEDNESDAY
NIGHT INTO THURSDAY...AS LARGE SCALE RIDGE CENTERED OVER THE REGION
SLIDES TO THE EAST. WAA RESPONSE AHEAD OF DIGGING UPSTREAM S/W AND
DEEPENING SFC CYCLONE COULD YIELD SOME LIGHT PRECIPITATION ACROSS
WESTERN AND NORTHERN AREAS LATE WEDNESDAY NIGHT INTO EARLY THURSDAY
MORNING. NARROW MID LVL FRONTOGENETIC BAND/CORRIDOR OF ISENTROPIC
ASCENT IS PROGGED TO CLIP THE NORTHWEST HALF OF THE AREA AFTER 00Z.
WHILE THE MID LVL FORCING AND MOISTURE LOOK SUFFICIENT FOR THE
DEVELOPMENT OF MEASURABLE PRECIP...LOW LEVELS LOOK EXTREMELY DRY
WITH THE ONSET OF THE FORCING...AND REMAIN FAIRLY DRY BELOW 850 MB
THROUGH THE OVERNIGHT. WILL STICK WITH THE SPRINKLE MENTION IN THE
FCST...AS COMPACT NATURE OF THE FRONTAL BAND/FORCING LOOKS TO BE
INCAPABLE OF SUFFICIENTLY SATURATING THE LOW LEVELS AND PRODUCING
MEASURABLE PRECIP.

AFTER A PLEASANT DAY ON THURSDAY...WITH NEAR TO SLIGHTLY ABOVE
NORMAL HIGH TEMPS IN THE MID TO UPPER 60S...PRECIPITATION CHANCES
WILL INCREASE LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT. A
FRONTAL BOUNDARY WILL APPROACH THE REGION FROM THE WEST...AS A
MID/UPPER S/W AND SFC LOW TRACK EAST ACROSS THE GREAT LAKES REGION.
LATEST MODEL SOLUTIONS GREATLY DIFFER WITH THE HANDLING OF THIS
SYSTEM. 12Z ECMWF REMAINS FARTHER NORTH WITH THE MID/UPPER LVL
ENERGY AND 500 MB JET...WITH A SEPARATE MID/UPPER LEVEL WAVE TRACKING
FROM THE SOUTHERN PLAINS INTO THE OHIO VALLEY. THE SOUTHERN
PERIPHERY OF THE TROF AXIS REMAINS NEUTRALLY TILTED...RESULTING IN A
SLOWER SOLUTION. 12Z GFS IS FARTHER SOUTH WITH THE MID LVL WAVE AND
JET...PHASING WITH THE SOUTHERN STREAM WAVE AS IT KICKS NORTHEAST
TOWARD THE REGION. THIS PHASED SYSTEM RESULTS IN A FASTER FRONTAL
PASSAGE. RESULTING FCST SOLUTION IS A BLEND OF THE PREVIOUS FORECAST
AND THE 12Z MODEL SOLUTIONS...WEIGHTED TOWARD THE 12Z ECMWF. THIS
FCST RESULTS IN POPS HOLDING OFF UNTIL 00Z EXCEPT FOR THE FAR WEST.
HELD WITH LIKELY POPS AND CHANCE THUNDER FROM 00Z TO 06Z...ALTHOUGH
THUNDER CHANCES LOOK MARGINAL AT BEST AT THIS POINT.

FORECAST CONFIDENCE CONTINUES TO DECREASE SIGNIFICANTLY FROM THIS
WEEKEND INTO NEXT WEEK. TEMPERATURES ON FRIDAY LOOK COMPARABLE TO
THURSDAY IN THE WAKE OF THE OCCLUDED FROPA...WITH TEMPERATURES IN
THE UPPER 60S TO LOW 70S. FRIDAY NIGHT AND BEYOND...LARGE SCALE
PATTERN BECOMES SIGNIFICANTLY UNCERTAIN WITH REGARDS TO TEMPERATURES
AND PRECIPITATION.

MODELS DEPICTING A SECONDARY FRONT SHIFTING SOUTH INTO THE AREA
FRIDAY NIGHT INTO SATURDAY...AS MID/UPPER S/W AND ASSOCIATED SFC LOW
TRACKS EAST OUT OF THE GREAT LAKES TOWARD NEW ENGLAND. THIS COULD
BRING SOME LIGHT RAIN SHOWER ACTIVITY TO THE AREA FRIDAY NIGHT...AND
BELOW NORMAL TEMPERATURES ON SATURDAY THROUGH THE WEEKEND.
NORTHERLY/NORTHWEST FLOW AND STRONG CANADIAN SFC HIGH PRESSURE LOOKS
TO REINFORCE THIS BAROCLINIC ZONE JUST SOUTH OF THE AREA...AND SHARP
MID/UPPER LEVEL RIDGING TAKES HOLD ACROSS THE PLAINS IN RESPONSE TO
DIGGING WRN CONUS UPPER TROF. THIS WOULD SUPPORT PERIODIC PRECIP
CHANCES ALONG THE BAROCLINIC ZONE...WITH BELOW NORMAL TEMPS FOR THE
AREA. THIS IS THE CONSENSUS FROM THE 12Z GFS AND GEFS MEAN. THE END
OF THE 09Z SREF AND 12Z GEM SUPPORT THIS IDEA...HOWEVER THE
BAROCLINIC ZONE DEPICTED IS FARTHER NORTH THAN THE GFS/GEFS
SOLUTION. THE 12Z ECMWF REMAINS THE FARTHEST NORTH WITH THE LATE
WEEK S/W...AND KEEPS THE SECONDARY FRONT UP ACROSS THE NORTHERN
GREAT LAKES THROUGH THE WEEKEND. THIS WOULD PLACE THE AREA IN THE
WARM SECTOR OF THIS SYSTEM...LIKELY YIELDING ABOVE NORMAL
TEMPERATURES FROM SATURDAY THROUGH MONDAY.

WITH THE WIDE RANGE OF SOLUTIONS...NO MAJOR CHANGES TO THE FORECAST
REGARDING TEMPS AND PRECIP AFTER FRIDAY NIGHT. HOWEVER...DID ADJUST
SATURDAY HIGH TEMPERATURES UP A FEW DEGREES...ESPECIALLY SOUTH...AS
MODELS AS A WHOLE ARE TRENDING TOWARD A SLOWER SOUTHWARD PUSH OF THE
SECONDARY FRONT...ALONG WITH DECREASING CONFIDENCE IN THE GEFS
MEAN...WITH 850 MB STANDARD DEVIATIONS AROUND 4C ACROSS THE LOWER
GREAT LAKES DURING THIS TIME PERIOD.

TOWARD THE END OF THE FCST PERIOD AND JUST BEYOND...MODELS STILL
INDICATE A MORE BLOCKED PATTERN ACROSS THE CONUS. LARGE CUTOFF LOW
LOOKS TO DEVELOP ACROSS THE CENTRAL CONUS BY MIDWEEK...AND SLOWLY
MEANDER ACROSS THE EASTERN CONUS. MEANWHILE...ANOTHER LARGE CUTOFF
LOW DEVELOPS ACROSS THE EASTERN PACIFIC/OFF THE CONUS WEST
COAST...WITH AN EXTREMELY AMPLIFIED WRN CONUS RIDGE. THIS BLOCK
WOULD PROVIDED AN EXTENDED PERIOD OF BELOW NORMAL TEMPS FROM MIDWEEK
THROUGH AT LEAST THE FIRST HALF OF THE WEEKEND...ALONG WITH PERIODIC
PRECIPITATION CHANCES...FOR MUCH OF THE EASTERN CONUS..INCLUDING OUR
FORECAST AREA.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1253 PM EDT TUE APR 22 2014

VFR / MAINLY CLEAR SKIES EXPECTED THROUGH THE PERIOD AS HIGH
PRESSURE BUILDS IN ON SUBSIDENT EASTERN FRINGE OF AN APPROACHING
MID LEVEL RIDGE. OTHERWISE...NNW WINDS OF 14-20 KTS (GUSTS 25 KTS)
THIS AFTERNOON WILL RAPIDLY DIMINISH EARLY THIS EVENING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...CEO
SHORT TERM...STEINWEDEL
LONG TERM...NG
AVIATION...STEINWEDEL


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FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
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000
FXUS63 KIND 221918
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
318 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 955 AM EDT TUE APR 22 2014

VISIBLE SATELLITE LOOP AT 1330Z SHOWS NORTHERN EDGE OF LOW CLOUD
DECK HAS REACHED AN AREA NEAR A LINE FROM COLUMBUS TO BLOOMINGTON
WITH SOLID CLOUD COVER TO THE SOUTH OF THE LINE AND CLEAR SKIES TO
THE NORTH. WINDS ARE GUSTING IN THE CLEAR AREA AT 20-30 KTS OUT OF
MAINLY THE NORTHWEST...WITH A FEW SITES SEEING A TEMPORARY SHIFT
TO THE NORTHEAST THAT SHOULD SHIFT BACK WITHIN A COUPLE HOURS AS
THE COLD FRONT MOVES FURTHER TO THE SOUTH AND EAST AWAY FROM THE
AREA. TEMPERATURES ARE DROPPING YET THIS MORNING AND MAY CONTINUE
TO DO SO FOR THE NEXT COUPLE OF HOURS BEFORE THEY START TO REBOUND
WITH FULL SUNSHINE THROUGH THE AFTERNOON. THUS GOING HIGHS IN THE
UPPER 50S TO MIDDLE 60S STILL LOOK GOOD.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TONIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT AND WINDS
STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT HOLD OFF ON
ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...

ISSUED AT 317 PM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE IS IN A LITTLE BETTER AGREEMENT...BUT THERE
ARE STILL DIFFERENCES EARLY NEXT WEEK.

MODELS INDICATE STRONG HIGH PRESSURE WILL BE OVER EASTERN CANADA AND
WITH A RIDGE EXTENDING SOUTH INTO OUR REGION SATURDAY. THUS SATURDAY
WILL BE COOL AND DRY. MODELS MOVE AN AREA OF LOW PRESSURE INTO THE
CENTRAL PLAINS SUNDAY AND MOVE IT TOWARDS OUR REGION MONDAY AND
TUESDAY.  A WARM FRONT WILL DEVELOP OVER THE LOWER MISSISSIPPI
VALLEY SUNDAY AND LIFT NORTH TOWARDS OUR REGION MONDAY AND TUESDAY
AS THE LOW PRESSURE SYSTEM APPROACHES.  THE GFS AND HPC STILL KEEPS
THE FRONTAL SYSTEM DEPRESSED TO OUR SOUTH MUCH OF THE PERIOD...WHILE
THE EURO AND LESSER EXTENT THE GEMNH MODELS MOVE IT QUICKLY NORTH
INTO OUR REGION.  FOR NOW WILL GO WITH A MODEL BLEND WITH INCREASING
CHANCES OF RAIN SHOWERS BEGINNING SUNDAY AND CONTINUING INTO MONDAY
AND TUESDAY.  THERE WILL ALSO BE INCREASING CHANCES OF A FEW
THUNDERSTORMS SUNDAY NIGHT INTO TUESDAY ESPECIALLY ACROSS OUR SOUTH.

IN REGARDS TO TEMPERATURES...CUT LOWS SLIGHTLY FRIDAY NIGHT AND
RAISED MINS A LITTLE SUNDAY AND MONDAY NIGHT DUE TO CLOUDS.
OTHERWISE...ONLY MINOR CHANGES MADE TO ALL BLEND TEMPERATURES.

&&

.AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/...
ISSUED AT 1240 PM EDT TUE APR 22 2014

VFR THROUGH THE PERIOD.

WIND GUSTS UP TO 25 KNOTS THIS AFTERNOON...BUT WINDS WILL BECOME
LIGHTER TONIGHT AND TUESDAY AS HIGH PRESSURE RIDGE OVER THE UPPER
MIDWEST DRIFTS EAST INTO OUR REGION.

EXPECT CLEAR SKIES THIS AFTERNOON AND TONIGHT. BUT WOULD NOT RULE
OUT A FEW CU SOME AREAS THIS AFTERNOON.  ON TUESDAY MODEL SOUNDINGS
INDICATE INCREASING HIGH CLOUDS WITH SOME MID CLOUDS BY MID OR LATE
AFTERNOON.

&&

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

$$

SYNOPSIS...NIELD
NEAR TERM...CP
SHORT TERM...NIELD
LONG TERM....JEH
AVIATION...JH

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

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








000
FXUS63 KIWX 221653
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1253 PM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 1203 PM EDT TUE APR 22 2014

COOLER AIR WILL CONTINUE TO FILTER INTO THE AREA THIS AFTERNOON AND
TONIGHT IN THE WAKE OF A DEPARTING COLD FRONT. GUSTY WINDS UP TO
30 MPH ARE ALSO POSSIBLE. HIGHS THIS AFTERNOON WILL GENERALLY BE
IN THE UPPER 40S TO 50S. LOWS TONIGHT WILL DROP TO NEAR OR BELOW
THE FREEZING MARK WITH AREAS OF FROST POSSIBLE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM EDT TUE APR 22 2014

SURFACE REFLECTION OF COLD FRONT JUST NOW CROSSING THE AREA DESPITE
BULK OF THE PRECIP...ASSOCIATED WITH A SUBTLE PREFRONTAL
TROUGH...NOW EXITING EASTWARD. A FEW SHOWERS HAVE MANAGED TO DEVELOP
RIGHT ALONG THE FRONT AND EXPECT ISOLATED RAIN WILL CONTINUE IN OUR
EASTERN ZONES THROUGH THE EARLY MORNING HOURS UNTIL FRONT FULLY
CLEARS THE CWA AROUND 12Z. DRY CONDITIONS THEN EXPECTED FOR THE REST
OF THE SHORT TERM PERIOD AS MIDLEVEL RIDGING AND ASSOCIATED CANADIAN
SURFACE HIGH GRADUALLY BUILD INTO THE REGION. PERSISTENT CAA AND
NORTHWEST FLOW OFF THE STILL VERY COLD WATERS OF LAKE MICHIGAN WILL
MUTE THE DIURNAL RESPONSE TODAY WITH AFTERNOON TEMPS NOT MUCH
DIFFERENT THAN PRESENT VALUES. 850MB TEMPS EXPECTED TO DROP BELOW 0C
BY THE AFTERNOON...CAPPING TEMPS FOR MOST AREAS IN THE LOW TO MID
50S WITH ONLY UPPER 40S EXPECTED NEAR THE LAKE. EXPECT A FAIR AMOUNT
OF SUN BUT NORTHWEST SURFACE WINDS MAY ALSO GUST TO NEAR 30 MPH
GIVEN STRONG PRESSURE GRADIENT AND DECENT MIXING HEIGHTS...MAKING IT
FEEL SOMEWHAT CHILLIER. THIS WILL SET THE STAGE FOR A COLD NIGHT
ACROSS THE AREA AS WELL. CORE OF THE THERMAL TROUGH WITH 850MB TEMPS
AROUND -6C DOES SKIRT BY TO OUR NORTHEAST BUT STILL EXPECT NEARLY
IDEAL RADIATIVE CONDITIONS WITH CLEAR SKIES AND A LIGHT NORTHERLY
WIND. WILL THEREFORE LEAN TOWARD COOLER GUIDANCE WITH MIN TEMPS IN
THE UPPER 20S TO AROUND 30F...SUPPORTING AREAS OF FROST OVER MOST OF
THE CWA. GROWING SEASON IS NOT YET IN FULL SWING SO NO FROST/FREEZE
HEADLINES NECESSARY. WILL HOWEVER ISSUE AN SPS TO ALERT THOSE WITH
SENSITIVE OUTDOOR VEGETATION.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 414 AM EDT TUE APR 22 2014

LONG TERM FORECAST TRENDING TOWARDS COOLER AND POTENTIALLY WETTER
PERIOD BUT LOW CONFIDENCE AND UNCERTAINTY CONTINUE FOR THE UPCOMING
WEEKEND AND EARLY PART OF NEXT WEEK.

WEDNESDAY WILL BEGIN WITH HIGH PRESSURE OVER THE AREA AND A VERY
COOL START. PLENTY OF INSOLATION DURING FIRST PART OF DAY WILL
HELP TEMPS REBOUND INTO THE 50S MOST AREAS. NAM12 SHOWS LAKE SHADOW
MAKING GOOD INLAND PROGRESS LATE MORNING TO EARLY AFTERNOON. EXPECT
TEMPS IN LAKE SHORE COUNTIES WILL STRUGGLE TO REACH 50 AND NEARBY
INLAND COUNTIES TO CLIMB INTO LOWER TO MID 50S BEFORE BECOMING
STEADY FOR FALLING BACK IN THE AFTERNOON AS MARINE LAYER MOVES
FARTHER INLAND. BETTER MIXING OUTSIDE OF LAKE SHADOW SUGGEST HIGHS
IN THE UPPER 50S TO POSSIBLY LOWER 60S.

MOST MODELS STILL TRYING TO GENERATE SOME LIGHT QPF OVER CENTRAL AND
NW AREAS WED NIGHT WITH DEVELOPING LOW LEVEL JET AND WARM AIR
ADVECTION. FORECAST SOUNDINGS CONTINUE TO SHOW VERY DRY LOWER LEVELS
SO IT WILL BE DIFFICULT TO FULLY SATURATE. WILL CONTINUE WITH
SPRINKLE MENTION FOR NOW AND SEE HOW MUCH MOISTURE RETURN DEVELOPS
FOR POSSIBLE BUMP IN POPS NEXT FEW FORECASTS. BETTER CHANCE FOR RAIN
STILL LOOKS TO BE THURSDAY NIGHT AHEAD OF OCCLUDED FRONT AS LOW
PRESSURE MOVES INTO THE GREAT LAKES. GOOD SHORT WAVE AND ASSOCIATED
LIFT SHOWN BY MODELS WITH BRIEF THETA E AND PWAT SURGE. LIKELY POPS
ON TARGET WITH AMOUNTS OF ONE QUARTER TO POSSIBLY ONE HALF INCH WITH
HEAVIER SHOWERS.

MILD DAY FOLLOWS OCCLUDED FRONT FOR FRIDAY WITH TEMPS SIMILAR TO
THURSDAY AND NEAR OR SLIGHTLY ABOVE NORMAL. SECONDARY FRONT DRIVES
SOUTH FRIDAY NIGHT WITH CHANCE FOR LIGHT SHOWERS. THIS WILL HELP SET
UP A RATHER PRONOUNCED BAROCLINIC ZONE ACROSS INDIANA FOR THE
WEEKEND AND EARLY NEXT WEEK. UPPER AIR PATTERN BECOMES MORE
MERIDIONAL AND BLOCKY WITH STALLED SFC FRONT JUST TO OUR SOUTH. THIS
LOOKS TO KEEP A COOL EASTERLY FLOW IN PLACE AT THE SURFACE LEADING
TO RETURN OF BELOW NORMAL TEMPERATURES. UNCERTAINTY INCREASES THIS
WEEKEND AND EARLY NEXT WEEK FOR POPS SO RELIANCE ON ENSEMBLES AND
BLENDS UNTIL FINER DETAILS CAN BE SORTED OUT.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1253 PM EDT TUE APR 22 2014

VFR / MAINLY CLEAR SKIES EXPECTED THROUGH THE PERIOD AS HIGH
PRESSURE BUILDS IN ON SUBSIDENT EASTERN FRINGE OF AN APPROACHING
MID LEVEL RIDGE. OTHERWISE...NNW WINDS OF 14-20 KTS (GUSTS 25 KTS)
THIS AFTERNOON WILL RAPIDLY DIMINISH EARLY THIS EVENING.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...CEO
SHORT TERM...AGD
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/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 221639
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1240 PM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 955 AM EDT TUE APR 22 2014

VISIBLE SATELLITE LOOP AT 1330Z SHOWS NORTHERN EDGE OF LOW CLOUD
DECK HAS REACHED AN AREA NEAR A LINE FROM COLUMBUS TO BLOOMINGTON
WITH SOLID CLOUD COVER TO THE SOUTH OF THE LINE AND CLEAR SKIES TO
THE NORTH. WINDS ARE GUSTING IN THE CLEAR AREA AT 20-30 KTS OUT OF
MAINLY THE NORTHWEST...WITH A FEW SITES SEEING A TEMPORARY SHIFT
TO THE NORTHEAST THAT SHOULD SHIFT BACK WITHIN A COUPLE HOURS AS
THE COLD FRONT MOVES FURTHER TO THE SOUTH AND EAST AWAY FROM THE
AREA. TEMPERATURES ARE DROPPING YET THIS MORNING AND MAY CONTINUE
TO DO SO FOR THE NEXT COUPLE OF HOURS BEFORE THEY START TO REBOUND
WITH FULL SUNSHINE THROUGH THE AFTERNOON. THUS GOING HIGHS IN THE
UPPER 50S TO MIDDLE 60S STILL LOOK GOOD.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TONIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT AND WINDS
STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT HOLD OFF ON
ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221800Z TAF ISSUANCE/...
ISSUED AT 1240 PM EDT TUE APR 22 2014

VFR THROUGH THE PERIOD.

WIND GUSTS UP TO 25 KNOTS THIS AFTERNOON...BUT WINDS WILL BECOME
LIGHTER TONIGHT AND TUESDAY AS HIGH PRESSURE RIDGE OVER THE UPPER
MIDWEST DRIFTS EAST INTO OUR REGION.

EXPECT CLEAR SKIES THIS AFTERNOON AND TONIGHT. BUT WOULD NOT RULE
OUT A FEW CU SOME AREAS THIS AFTERNOON.  ON TUESDAY MODEL SOUNDINGS
INDICATE INCREASING HIGH CLOUDS WITH SOME MID CLOUDS BY MID OR LATE
AFTERNOON.

&&

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

$$

SYNOPSIS...NIELD
NEAR TERM...CP
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...JH

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

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














000
FXUS63 KIWX 221604
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1204 PM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 1203 PM EDT TUE APR 22 2014

COOLER AIR WILL CONTINUE TO FILTER INTO THE AREA THIS AFTERNOON AND
TONIGHT IN THE WAKE OF A DEPARTING COLD FRONT. GUSTY WINDS UP TO
30 MPH ARE ALSO POSSIBLE. HIGHS THIS AFTERNOON WILL GENERALLY BE
IN THE UPPER 40S TO 50S. LOWS TONIGHT WILL DROP TO NEAR OR BELOW
THE FREEZING MARK WITH AREAS OF FROST POSSIBLE.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM EDT TUE APR 22 2014

SURFACE REFLECTION OF COLD FRONT JUST NOW CROSSING THE AREA DESPITE
BULK OF THE PRECIP...ASSOCIATED WITH A SUBTLE PREFRONTAL
TROUGH...NOW EXITING EASTWARD. A FEW SHOWERS HAVE MANAGED TO DEVELOP
RIGHT ALONG THE FRONT AND EXPECT ISOLATED RAIN WILL CONTINUE IN OUR
EASTERN ZONES THROUGH THE EARLY MORNING HOURS UNTIL FRONT FULLY
CLEARS THE CWA AROUND 12Z. DRY CONDITIONS THEN EXPECTED FOR THE REST
OF THE SHORT TERM PERIOD AS MIDLEVEL RIDGING AND ASSOCIATED CANADIAN
SURFACE HIGH GRADUALLY BUILD INTO THE REGION. PERSISTENT CAA AND
NORTHWEST FLOW OFF THE STILL VERY COLD WATERS OF LAKE MICHIGAN WILL
MUTE THE DIURNAL RESPONSE TODAY WITH AFTERNOON TEMPS NOT MUCH
DIFFERENT THAN PRESENT VALUES. 850MB TEMPS EXPECTED TO DROP BELOW 0C
BY THE AFTERNOON...CAPPING TEMPS FOR MOST AREAS IN THE LOW TO MID
50S WITH ONLY UPPER 40S EXPECTED NEAR THE LAKE. EXPECT A FAIR AMOUNT
OF SUN BUT NORTHWEST SURFACE WINDS MAY ALSO GUST TO NEAR 30 MPH
GIVEN STRONG PRESSURE GRADIENT AND DECENT MIXING HEIGHTS...MAKING IT
FEEL SOMEWHAT CHILLIER. THIS WILL SET THE STAGE FOR A COLD NIGHT
ACROSS THE AREA AS WELL. CORE OF THE THERMAL TROUGH WITH 850MB TEMPS
AROUND -6C DOES SKIRT BY TO OUR NORTHEAST BUT STILL EXPECT NEARLY
IDEAL RADIATIVE CONDITIONS WITH CLEAR SKIES AND A LIGHT NORTHERLY
WIND. WILL THEREFORE LEAN TOWARD COOLER GUIDANCE WITH MIN TEMPS IN
THE UPPER 20S TO AROUND 30F...SUPPORTING AREAS OF FROST OVER MOST OF
THE CWA. GROWING SEASON IS NOT YET IN FULL SWING SO NO FROST/FREEZE
HEADLINES NECESSARY. WILL HOWEVER ISSUE AN SPS TO ALERT THOSE WITH
SENSITIVE OUTDOOR VEGETATION.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 414 AM EDT TUE APR 22 2014

LONG TERM FORECAST TRENDING TOWARDS COOLER AND POTENTIALLY WETTER
PERIOD BUT LOW CONFIDENCE AND UNCERTAINTY CONTINUE FOR THE UPCOMING
WEEKEND AND EARLY PART OF NEXT WEEK.

WEDNESDAY WILL BEGIN WITH HIGH PRESSURE OVER THE AREA AND A VERY
COOL START. PLENTY OF INSOLATION DURING FIRST PART OF DAY WILL
HELP TEMPS REBOUND INTO THE 50S MOST AREAS. NAM12 SHOWS LAKE SHADOW
MAKING GOOD INLAND PROGRESS LATE MORNING TO EARLY AFTERNOON. EXPECT
TEMPS IN LAKE SHORE COUNTIES WILL STRUGGLE TO REACH 50 AND NEARBY
INLAND COUNTIES TO CLIMB INTO LOWER TO MID 50S BEFORE BECOMING
STEADY FOR FALLING BACK IN THE AFTERNOON AS MARINE LAYER MOVES
FARTHER INLAND. BETTER MIXING OUTSIDE OF LAKE SHADOW SUGGEST HIGHS
IN THE UPPER 50S TO POSSIBLY LOWER 60S.

MOST MODELS STILL TRYING TO GENERATE SOME LIGHT QPF OVER CENTRAL AND
NW AREAS WED NIGHT WITH DEVELOPING LOW LEVEL JET AND WARM AIR
ADVECTION. FORECAST SOUNDINGS CONTINUE TO SHOW VERY DRY LOWER LEVELS
SO IT WILL BE DIFFICULT TO FULLY SATURATE. WILL CONTINUE WITH
SPRINKLE MENTION FOR NOW AND SEE HOW MUCH MOISTURE RETURN DEVELOPS
FOR POSSIBLE BUMP IN POPS NEXT FEW FORECASTS. BETTER CHANCE FOR RAIN
STILL LOOKS TO BE THURSDAY NIGHT AHEAD OF OCCLUDED FRONT AS LOW
PRESSURE MOVES INTO THE GREAT LAKES. GOOD SHORT WAVE AND ASSOCIATED
LIFT SHOWN BY MODELS WITH BRIEF THETA E AND PWAT SURGE. LIKELY POPS
ON TARGET WITH AMOUNTS OF ONE QUARTER TO POSSIBLY ONE HALF INCH WITH
HEAVIER SHOWERS.

MILD DAY FOLLOWS OCCLUDED FRONT FOR FRIDAY WITH TEMPS SIMILAR TO
THURSDAY AND NEAR OR SLIGHTLY ABOVE NORMAL. SECONDARY FRONT DRIVES
SOUTH FRIDAY NIGHT WITH CHANCE FOR LIGHT SHOWERS. THIS WILL HELP SET
UP A RATHER PRONOUNCED BAROCLINIC ZONE ACROSS INDIANA FOR THE
WEEKEND AND EARLY NEXT WEEK. UPPER AIR PATTERN BECOMES MORE
MERIDIONAL AND BLOCKY WITH STALLED SFC FRONT JUST TO OUR SOUTH. THIS
LOOKS TO KEEP A COOL EASTERLY FLOW IN PLACE AT THE SURFACE LEADING
TO RETURN OF BELOW NORMAL TEMPERATURES. UNCERTAINTY INCREASES THIS
WEEKEND AND EARLY NEXT WEEK FOR POPS SO RELIANCE ON ENSEMBLES AND
BLENDS UNTIL FINER DETAILS CAN BE SORTED OUT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 554 AM EDT TUE APR 22 2014

SURFACE COLD FRONT HAS NOW CLEARED KSBN AND WILL CLEAR KFWA WITHIN
THE NEXT FEW HOURS. STRONG SURGE OF DRY AIR BEHIND THE FRONT IS
EXPECTED TO BRING MOSTLY CLEAR SKIES FOR THE REST OF THE TAF
PERIOD. TIGHT PRESSURE GRADIENT AND DEEP BOUNDARY LAYER MIXING
WILL SUPPORT WIND GUSTS OF AROUND 25 KTS FOR MUCH OF THE DAY
THOUGH.


&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...AGD


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

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







000
FXUS63 KIND 221425
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1025 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 955 AM EDT TUE APR 22 2014

VISIBLE SATELLITE LOOP AT 1330Z SHOWS NORTHERN EDGE OF LOW CLOUD
DECK HAS REACHED AN AREA NEAR A LINE FROM COLUMBUS TO BLOOMINGTON
WITH SOLID CLOUD COVER TO THE SOUTH OF THE LINE AND CLEAR SKIES TO
THE NORTH. WINDS ARE GUSTING IN THE CLEAR AREA AT 20-30 KTS OUT OF
MAINLY THE NORTHWEST...WITH A FEW SITES SEEING A TEMPORARY SHIFT
TO THE NORTHEAST THAT SHOULD SHIFT BACK WITHIN A COUPLE HOURS AS
THE COLD FRONT MOVES FURTHER TO THE SOUTH AND EAST AWAY FROM THE
AREA. TEMPERATURES ARE DROPPING YET THIS MORNING AND MAY CONTINUE
TO DO SO FOR THE NEXT COUPLE OF HOURS BEFORE THEY START TO REBOUND
WITH FULL SUNSHINE THROUGH THE AFTERNOON. THUS GOING HIGHS IN THE
UPPER 50S TO MIDDLE 60S STILL LOOK GOOD.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TONIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT AND WINDS
STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT HOLD OFF ON
ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221500Z KIND TAF UPDATE/...
ISSUED AT 1025 AM EDT TUE APR 22 2014

MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS. NO
OTHER CHANGES NEEDED AT THIS TIME. PORTION OF PREVIOUS AVIATION
DISCUSSION FOLLOWS...

VFR THROUGH THE PERIOD.

COLD FRONT HAS NOW CLEARED ALL TERMINALS WITH DEEPER MOISTURE
RAPIDLY SHIFTING EAST AWAY FROM THE REGION.

DESPITE INCREASING LOW LEVEL COLD ADVECTION THROUGHOUT THE
DAY...LITTLE IN THE WAY OF CLOUDS EXPECTED THE REST OF THE DAY AS
MODEL SOUNDINGS SHOWING DEEP SUBSIDENCE OVERSPREADING THE FORECAST
AREA AS HIGH PRESSURE BUILDS IN. MAIN IMPACT TO AVIATORS TODAY WILL
BE THE GUSTY NORTHWEST WINDS AS SUSTAINEDS PEAK AT 15-20KTS AND
GUSTS AROUND 30KTS. GUSTS WILL DROP OFF QUICKLY WITH SUNSET...WITH
N/NE WINDS DIMINISHING TO AROUND 5KTS UNDER CLEAR SKIES TONIGHT.


&&

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

$$

SYNOPSIS...NIELD
NEAR TERM...CP
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN/JH

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

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











000
FXUS63 KIND 221402
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1002 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /REST OF TODAY/...

ISSUED AT 955 AM EDT TUE APR 22 2014

VISIBLE SATELLITE LOOP AT 1330Z SHOWS NORTHERN EDGE OF LOW CLOUD
DECK HAS REACHED AN AREA NEAR A LINE FROM COLUMBUS TO BLOOMINGTON
WITH SOLID CLOUD COVER TO THE SOUTH OF THE LINE AND CLEAR SKIES TO
THE NORTH. WINDS ARE GUSTING IN THE CLEAR AREA AT 20-30 KTS OUT OF
MAINLY THE NORTHWEST...WITH A FEW SITES SEEING A TEMPORARY SHIFT
TO THE NORTHEAST THAT SHOULD SHIFT BACK WITHIN A COUPLE HOURS AS
THE COLD FRONT MOVES FURTHER TO THE SOUTH AND EAST AWAY FROM THE
AREA. TEMPERATURES ARE DROPPING YET THIS MORNING AND MAY CONTINUE
TO DO SO FOR THE NEXT COUPLE OF HOURS BEFORE THEY START TO REBOUND
WITH FULL SUNSHINE THROUGH THE AFTERNOON. THUS GOING HIGHS IN THE
UPPER 50S TO MIDDLE 60S STILL LOOK GOOD.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TONIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT AND WINDS
STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT HOLD OFF ON
ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221200Z TAF ISSUANCE/...
ISSUED AT 612 AM EDT TUE APR 22 2014

BRIEF MVFR CONDITIONS POSSIBLE EARLY THIS MORNING...THEN VFR EXPECTED.

COLD FRONT HAS NOW CLEARED ALL TERMINALS WITH DEEPER MOISTURE
RAPIDLY SHIFTING EAST AWAY FROM THE REGION. STILL DEALING WITH
POCKETS OF MVFR VISIBILITIES AND STRATUS TRAILING THE BOUNDARY...
BUT ANTICIPATE LOWER CEILINGS WILL BE EAST OF KBMG AND KIND WITHIN
A FEW HOURS.

DESPITE INCREASING LOW LEVEL COLD ADVECTION THROUGHOUT THE
DAY...LITTLE IN THE WAY OF CLOUDS EXPECTED THE REST OF THE DAY AS
MODEL SOUNDINGS SHOWING DEEP SUBSIDENCE OVERSPREADING THE FORECAST
AREA AS HIGH PRESSURE BUILDS IN. MAIN IMPACT TO AVIATORS TODAY WILL
BE THE GUSTY NORTHWEST WINDS AS SUSTAINEDS PEAK AT 15-20KTS AND
GUSTS AROUND 30KTS. GUSTS WILL DROP OFF QUICKLY WITH SUNSET...WITH
N/NE WINDS DIMINISHING TO AROUND 5KTS UNDER CLEAR SKIES TONIGHT.


&&

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

$$

SYNOPSIS...NIELD
NEAR TERM...CP
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...RYAN

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

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








000
FXUS63 KIND 221013
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /TODAY/...
ISSUED AT 401 AM EDT TUE APR 22 2014

EXPECT FRONT TO BE ON ITS WAY OUT OF THE AREA AT 12Z...AND PRECIP
HAS BEEN ISOLATED AND VERY LIGHT AT BEST FOR SEVERAL HOURS...SO
CONFIDENT THAT NO POPS WILL BE NECESSARY TODAY. CLEARING LINE IS
ADVANCING STEADILY...AND EXPECT MOST OF THE AREA TO BE CLEAR OR
MOSTLY CLEAR BY MID TO LATE MORNING.

MODEL SOUNDINGS SUGGEST FAIRLY GOOD MIXING TODAY AND SOME WIND
GUSTS UP TO 30 MPH...AND HAVE INCLUDED THIS IN THE GRIDS. GUSTS
WILL DIE DOWN IN TYPICAL DIURNAL FASHION THIS EVENING.

CONSENSUS NUMBERS APPEARED TOO COOL BASED ON UPSTREAM NUMBERS AND
LOW LEVEL THICKNESSES...SO BUMPED UP CLOSER TO A MOS BLEND.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TONIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT AND WINDS
STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT HOLD OFF ON
ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221200Z TAF ISSUANCE/...
ISSUED AT 612 AM EDT TUE APR 22 2014

BRIEF MVFR CONDITIONS POSSIBLE EARLY THIS MORNING...THEN VFR EXPECTED.

COLD FRONT HAS NOW CLEARED ALL TERMINALS WITH DEEPER MOISTURE
RAPIDLY SHIFTING EAST AWAY FROM THE REGION. STILL DEALING WITH
POCKETS OF MVFR VISIBILITIES AND STRATUS TRAILING THE BOUNDARY...
BUT ANTICIPATE LOWER CEILINGS WILL BE EAST OF KBMG AND KIND WITHIN
A FEW HOURS.

DESPITE INCREASING LOW LEVEL COLD ADVECTION THROUGHOUT THE
DAY...LITTLE IN THE WAY OF CLOUDS EXPECTED THE REST OF THE DAY AS
MODEL SOUNDINGS SHOWING DEEP SUBSIDENCE OVERSPREADING THE FORECAST
AREA AS HIGH PRESSURE BUILDS IN. MAIN IMPACT TO AVIATORS TODAY WILL
BE THE GUSTY NORTHWEST WINDS AS SUSTAINEDS PEAK AT 15-20KTS AND
GUSTS AROUND 30KTS. GUSTS WILL DROP OFF QUICKLY WITH SUNSET...WITH
N/NE WINDS DIMINISHING TO AROUND 5KTS UNDER CLEAR SKIES TONIGHT.

&&

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

&&

$$

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

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

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














000
FXUS63 KIND 221012
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /TODAY/...
ISSUED AT 401 AM EDT TUE APR 22 2014

EXPECT FRONT TO BE ON ITS WAY OUT OF THE AREA AT 12Z...AND PRECIP
HAS BEEN ISOLATED AND VERY LIGHT AT BEST FOR SEVERAL HOURS...SO
CONFIDENT THAT NO POPS WILL BE NECESSARY TODAY. CLEARING LINE IS
ADVANCING STEADILY...AND EXPECT MOST OF THE AREA TO BE CLEAR OR
MOSTLY CLEAR BY MID TO LATE MORNING.

MODEL SOUNDINGS SUGGEST FAIRLY GOOD MIXING TODAY AND SOME WIND
GUSTS UP TO 30 MPH...AND HAVE INCLUDED THIS IN THE GRIDS. GUSTS
WILL DIE DOWN IN TYPICAL DIURNAL FASHION THIS EVENING.

CONSENSUS NUMBERS APPEARED TOO COOL BASED ON UPSTREAM NUMBERS AND
LOW LEVEL THICKNESSES...SO BUMPED UP CLOSER TO A MOS BLEND.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TOMORROW NIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT
AND WINDS STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT
HOLD OFF ON ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221200Z TAF ISSUANCE/...
ISSUED AT 612 AM EDT TUE APR 22 2014

BRIEF MVFR CONDITIONS POSSIBLE EARLY THIS MORNING...THEN VFR EXPECTED.

COLD FRONT HAS NOW CLEARED ALL TERMINALS WITH DEEPER MOISTURE
RAPIDLY SHIFTING EAST AWAY FROM THE REGION. STILL DEALING WITH
POCKETS OF MVFR VISIBILITIES AND STRATUS TRAILING THE BOUNDARY...
BUT ANTICIPATE LOWER CEILINGS WILL BE EAST OF KBMG AND KIND WITHIN
A FEW HOURS.

DESPITE INCREASING LOW LEVEL COLD ADVECTION THROUGHOUT THE
DAY...LITTLE IN THE WAY OF CLOUDS EXPECTED THE REST OF THE DAY AS
MODEL SOUNDINGS SHOWING A DEEP SUBSIDENCE OVERSPREADING THE
FORECAST AREA AS HIGH PRESSURE BUILDS IN. MAIN IMPACT TO AVIATORS
TODAY WILL BE THE GUSTY NORTHWEST WINDS AS SUSTAINEDS PEAK AT
15-20KTS AND GUSTS AROUND 30KTS. GUSTS WILL DROP OFF QUICKLY WITH
SUNSET...WITH N/NE WINDS DIMINISHING TO AROUND 5KTS UNDER CLEAR
SKIES TONIGHT.

&&

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

&&

$$

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

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 221012
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
612 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /TODAY/...
ISSUED AT 401 AM EDT TUE APR 22 2014

EXPECT FRONT TO BE ON ITS WAY OUT OF THE AREA AT 12Z...AND PRECIP
HAS BEEN ISOLATED AND VERY LIGHT AT BEST FOR SEVERAL HOURS...SO
CONFIDENT THAT NO POPS WILL BE NECESSARY TODAY. CLEARING LINE IS
ADVANCING STEADILY...AND EXPECT MOST OF THE AREA TO BE CLEAR OR
MOSTLY CLEAR BY MID TO LATE MORNING.

MODEL SOUNDINGS SUGGEST FAIRLY GOOD MIXING TODAY AND SOME WIND
GUSTS UP TO 30 MPH...AND HAVE INCLUDED THIS IN THE GRIDS. GUSTS
WILL DIE DOWN IN TYPICAL DIURNAL FASHION THIS EVENING.

CONSENSUS NUMBERS APPEARED TOO COOL BASED ON UPSTREAM NUMBERS AND
LOW LEVEL THICKNESSES...SO BUMPED UP CLOSER TO A MOS BLEND.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TOMORROW NIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT
AND WINDS STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT
HOLD OFF ON ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR 221200Z TAF ISSUANCE/...
ISSUED AT 612 AM EDT TUE APR 22 2014

BRIEF MVFR CONDITIONS POSSIBLE EARLY THIS MORNING...THEN VFR EXPECTED.

COLD FRONT HAS NOW CLEARED ALL TERMINALS WITH DEEPER MOISTURE
RAPIDLY SHIFTING EAST AWAY FROM THE REGION. STILL DEALING WITH
POCKETS OF MVFR VISIBILITIES AND STRATUS TRAILING THE BOUNDARY...
BUT ANTICIPATE LOWER CEILINGS WILL BE EAST OF KBMG AND KIND WITHIN
A FEW HOURS.

DESPITE INCREASING LOW LEVEL COLD ADVECTION THROUGHOUT THE
DAY...LITTLE IN THE WAY OF CLOUDS EXPECTED THE REST OF THE DAY AS
MODEL SOUNDINGS SHOWING DEEP SUBSIDENCE OVERSPREADING THE FORECAST
AREA AS HIGH PRESSURE BUILDS IN. MAIN IMPACT TO AVIATORS TODAY WILL
BE THE GUSTY NORTHWEST WINDS AS SUSTAINEDS PEAK AT 15-20KTS AND
GUSTS AROUND 30KTS. GUSTS WILL DROP OFF QUICKLY WITH SUNSET...WITH
N/NE WINDS DIMINISHING TO AROUND 5KTS UNDER CLEAR SKIES TONIGHT.

&&

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

&&

$$

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

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

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











000
FXUS63 KIWX 220954
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
554 AM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 414 AM EDT TUE APR 22 2014

A COLD FRONT CURRENTLY PASSING THROUGH THE REGION WILL USHER IN MUCH
COLDER AIR FOR TODAY AND TONIGHT. HIGHS WILL GENERALLY BE IN THE 50S
WITH OVERNIGHT LOWS AROUND 30. NORTHWEST WINDS MAY ALSO GUST TO
AROUND 30 MPH TODAY...MAKING IT FEEL EVEN CHILLIER DESPITE MOSTLY
SUNNY SKIES. SLOW MODERATION IN TEMPERATURES EXPECTED THROUGH THE
END OF THE WEEK BEFORE ANOTHER COLD FRONT ARRIVES ON FRIDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM EDT TUE APR 22 2014

SURFACE REFLECTION OF COLD FRONT JUST NOW CROSSING THE AREA DESPITE
BULK OF THE PRECIP...ASSOCIATED WITH A SUBTLE PREFRONTAL
TROUGH...NOW EXITING EASTWARD. A FEW SHOWERS HAVE MANAGED TO DEVELOP
RIGHT ALONG THE FRONT AND EXPECT ISOLATED RAIN WILL CONTINUE IN OUR
EASTERN ZONES THROUGH THE EARLY MORNING HOURS UNTIL FRONT FULLY
CLEARS THE CWA AROUND 12Z. DRY CONDITIONS THEN EXPECTED FOR THE REST
OF THE SHORT TERM PERIOD AS MIDLEVEL RIDGING AND ASSOCIATED CANADIAN
SURFACE HIGH GRADUALLY BUILD INTO THE REGION. PERSISTENT CAA AND
NORTHWEST FLOW OFF THE STILL VERY COLD WATERS OF LAKE MICHIGAN WILL
MUTE THE DIURNAL RESPONSE TODAY WITH AFTERNOON TEMPS NOT MUCH
DIFFERENT THAN PRESENT VALUES. 850MB TEMPS EXPECTED TO DROP BELOW 0C
BY THE AFTERNOON...CAPPING TEMPS FOR MOST AREAS IN THE LOW TO MID
50S WITH ONLY UPPER 40S EXPECTED NEAR THE LAKE. EXPECT A FAIR AMOUNT
OF SUN BUT NORTHWEST SURFACE WINDS MAY ALSO GUST TO NEAR 30 MPH
GIVEN STRONG PRESSURE GRADIENT AND DECENT MIXING HEIGHTS...MAKING IT
FEEL SOMEWHAT CHILLIER. THIS WILL SET THE STAGE FOR A COLD NIGHT
ACROSS THE AREA AS WELL. CORE OF THE THERMAL TROUGH WITH 850MB TEMPS
AROUND -6C DOES SKIRT BY TO OUR NORTHEAST BUT STILL EXPECT NEARLY
IDEAL RADIATIVE CONDITIONS WITH CLEAR SKIES AND A LIGHT NORTHERLY
WIND. WILL THEREFORE LEAN TOWARD COOLER GUIDANCE WITH MIN TEMPS IN
THE UPPER 20S TO AROUND 30F...SUPPORTING AREAS OF FROST OVER MOST OF
THE CWA. GROWING SEASON IS NOT YET IN FULL SWING SO NO FROST/FREEZE
HEADLINES NECESSARY. WILL HOWEVER ISSUE AN SPS TO ALERT THOSE WITH
SENSITIVE OUTDOOR VEGETATION.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 414 AM EDT TUE APR 22 2014

LONG TERM FORECAST TRENDING TOWARDS COOLER AND POTENTIALLY WETTER
PERIOD BUT LOW CONFIDENCE AND UNCERTAINTY CONTINUE FOR THE UPCOMING
WEEKEND AND EARLY PART OF NEXT WEEK.

WEDNESDAY WILL BEGIN WITH HIGH PRESSURE OVER THE AREA AND A VERY
COOL START. PLENTY OF INSOLATION DURING FIRST PART OF DAY WILL
HELP TEMPS REBOUND INTO THE 50S MOST AREAS. NAM12 SHOWS LAKE SHADOW
MAKING GOOD INLAND PROGRESS LATE MORNING TO EARLY AFTERNOON. EXPECT
TEMPS IN LAKE SHORE COUNTIES WILL STRUGGLE TO REACH 50 AND NEARBY
INLAND COUNTIES TO CLIMB INTO LOWER TO MID 50S BEFORE BECOMING
STEADY FOR FALLING BACK IN THE AFTERNOON AS MARINE LAYER MOVES
FARTHER INLAND. BETTER MIXING OUTSIDE OF LAKE SHADOW SUGGEST HIGHS
IN THE UPPER 50S TO POSSIBLY LOWER 60S.

MOST MODELS STILL TRYING TO GENERATE SOME LIGHT QPF OVER CENTRAL AND
NW AREAS WED NIGHT WITH DEVELOPING LOW LEVEL JET AND WARM AIR
ADVECTION. FORECAST SOUNDINGS CONTINUE TO SHOW VERY DRY LOWER LEVELS
SO IT WILL BE DIFFICULT TO FULLY SATURATE. WILL CONTINUE WITH
SPRINKLE MENTION FOR NOW AND SEE HOW MUCH MOISTURE RETURN DEVELOPS
FOR POSSIBLE BUMP IN POPS NEXT FEW FORECASTS. BETTER CHANCE FOR RAIN
STILL LOOKS TO BE THURSDAY NIGHT AHEAD OF OCCLUDED FRONT AS LOW
PRESSURE MOVES INTO THE GREAT LAKES. GOOD SHORT WAVE AND ASSOCIATED
LIFT SHOWN BY MODELS WITH BRIEF THETA E AND PWAT SURGE. LIKELY POPS
ON TARGET WITH AMOUNTS OF ONE QUARTER TO POSSIBLY ONE HALF INCH WITH
HEAVIER SHOWERS.

MILD DAY FOLLOWS OCCLUDED FRONT FOR FRIDAY WITH TEMPS SIMILAR TO
THURSDAY AND NEAR OR SLIGHTLY ABOVE NORMAL. SECONDARY FRONT DRIVES
SOUTH FRIDAY NIGHT WITH CHANCE FOR LIGHT SHOWERS. THIS WILL HELP SET
UP A RATHER PRONOUNCED BAROCLINIC ZONE ACROSS INDIANA FOR THE
WEEKEND AND EARLY NEXT WEEK. UPPER AIR PATTERN BECOMES MORE
MERIDIONAL AND BLOCKY WITH STALLED SFC FRONT JUST TO OUR SOUTH. THIS
LOOKS TO KEEP A COOL EASTERLY FLOW IN PLACE AT THE SURFACE LEADING
TO RETURN OF BELOW NORMAL TEMPERATURES. UNCERTAINTY INCREASES THIS
WEEKEND AND EARLY NEXT WEEK FOR POPS SO RELIANCE ON ENSEMBLES AND
BLENDS UNTIL FINER DETAILS CAN BE SORTED OUT.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 554 AM EDT TUE APR 22 2014

SURFACE COLD FRONT HAS NOW CLEARED KSBN AND WILL CLEAR KFWA WITHIN
THE NEXT FEW HOURS. STRONG SURGE OF DRY AIR BEHIND THE FRONT IS
EXPECTED TO BRING MOSTLY CLEAR SKIES FOR THE REST OF THE TAF
PERIOD. TIGHT PRESSURE GRADIENT AND DEEP BOUNDARY LAYER MIXING
WILL SUPPORT WIND GUSTS OF AROUND 25 KTS FOR MUCH OF THE DAY
THOUGH.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...AGD


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

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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA








000
FXUS63 KIND 220833
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
433 AM EDT TUE APR 22 2014

.UPDATE...

THE AVIATION SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /TODAY/...
ISSUED AT 401 AM EDT TUE APR 22 2014

EXPECT FRONT TO BE ON ITS WAY OUT OF THE AREA AT 12Z...AND PRECIP
HAS BEEN ISOLATED AND VERY LIGHT AT BEST FOR SEVERAL HOURS...SO
CONFIDENT THAT NO POPS WILL BE NECESSARY TODAY. CLEARING LINE IS
ADVANCING STEADILY...AND EXPECT MOST OF THE AREA TO BE CLEAR OR
MOSTLY CLEAR BY MID TO LATE MORNING.

MODEL SOUNDINGS SUGGEST FAIRLY GOOD MIXING TODAY AND SOME WIND
GUSTS UP TO 30 MPH...AND HAVE INCLUDED THIS IN THE GRIDS. GUSTS
WILL DIE DOWN IN TYPICAL DIURNAL FASHION THIS EVENING.

CONSENSUS NUMBERS APPEARED TOO COOL BASED ON UPSTREAM NUMBERS AND
LOW LEVEL THICKNESSES...SO BUMPED UP CLOSER TO A MOS BLEND.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TOMORROW NIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT
AND WINDS STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT
HOLD OFF ON ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR THE 220900Z TAF UPDATE/...
ISSUED AT 433 AM EDT TUE APR 22 2014

ALL OF THE PRECIP HAS SHIFTED EAST OF THE TERMINALS AS THE COLD
FRONT IS ABOUT TO PASS KHUF AND KIND. WINDS WILL GRADUALLY VEER TO
NORTHWEST AND INCREASE TO 10-15KTS BY DAYBREAK AS THE FRONT PASSES.
POCKETS OF MVFR VISIBILITIES AND STRATUS BEHIND THE BOUNDARY WILL
IMPACT ALL OF THE TERMINALS OVER THE NEXT 2-4 HOURS. CLEARING SKIES
WILL THEN FOLLOW AS THE HIGH BUILDS IN.

06Z DISCUSSION FOLLOWS.

MOSTLY VFR...HOWEVER FIRST TO START OFF THE PERIOD A PERIOD OF MVFR
CEILINGS POSSIBLE THROUGH EARLY THIS MORNING WITH SCATTERED SHOWER
ACTIVITY. MODERATE TO BRISK WINDS WILL OCCUR TODAY...FIRST ALONG THE
FRONT AND THEN POST FRONTAL PASSAGE.

WILL CONTINUE TO OMIT MENTION OF THUNDER AS THERE CURRENTLY IS VERY
LITTLE CONVECTION ON THE RADAR. FOLLOWING THE COLD FRONT MUCH DRIER
AIR WILL SPREAD IN FROM THE NORTHWEST CAUSING RAPID CLEARING BY MID
OR LATE MORNING. WINDS WILL BE BECOMING NORTHWEST AND INCREASING UP
TO 15 KNOTS AND GUSTS TO 25 KNOTS BY 15Z THIS MORNING.

&&

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

&&

$$

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

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIWX 220814
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
414 AM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 414 AM EDT TUE APR 22 2014

A COLD FRONT CURRENTLY PASSING THROUGH THE REGION WILL USHER IN MUCH
COLDER AIR FOR TODAY AND TONIGHT. HIGHS WILL GENERALLY BE IN THE 50S
WITH OVERNIGHT LOWS AROUND 30. NORTHWEST WINDS MAY ALSO GUST TO
AROUND 30 MPH TODAY...MAKING IT FEEL EVEN CHILLIER DESPITE MOSTLY
SUNNY SKIES. SLOW MODERATION IN TEMPERATURES EXPECTED THROUGH THE
END OF THE WEEK BEFORE ANOTHER COLD FRONT ARRIVES ON FRIDAY.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 414 AM EDT TUE APR 22 2014

SURFACE REFLECTION OF COLD FRONT JUST NOW CROSSING THE AREA DESPITE
BULK OF THE PRECIP...ASSOCIATED WITH A SUBTLE PREFRONTAL
TROUGH...NOW EXITING EASTWARD. A FEW SHOWERS HAVE MANAGED TO DEVELOP
RIGHT ALONG THE FRONT AND EXPECT ISOLATED RAIN WILL CONTINUE IN OUR
EASTERN ZONES THROUGH THE EARLY MORNING HOURS UNTIL FRONT FULLY
CLEARS THE CWA AROUND 12Z. DRY CONDITIONS THEN EXPECTED FOR THE REST
OF THE SHORT TERM PERIOD AS MIDLEVEL RIDGING AND ASSOCIATED CANADIAN
SURFACE HIGH GRADUALLY BUILD INTO THE REGION. PERSISTENT CAA AND
NORTHWEST FLOW OFF THE STILL VERY COLD WATERS OF LAKE MICHIGAN WILL
MUTE THE DIURNAL RESPONSE TODAY WITH AFTERNOON TEMPS NOT MUCH
DIFFERENT THAN PRESENT VALUES. 850MB TEMPS EXPECTED TO DROP BELOW 0C
BY THE AFTERNOON...CAPPING TEMPS FOR MOST AREAS IN THE LOW TO MID
50S WITH ONLY UPPER 40S EXPECTED NEAR THE LAKE. EXPECT A FAIR AMOUNT
OF SUN BUT NORTHWEST SURFACE WINDS MAY ALSO GUST TO NEAR 30 MPH
GIVEN STRONG PRESSURE GRADIENT AND DECENT MIXING HEIGHTS...MAKING IT
FEEL SOMEWHAT CHILLIER. THIS WILL SET THE STAGE FOR A COLD NIGHT
ACROSS THE AREA AS WELL. CORE OF THE THERMAL TROUGH WITH 850MB TEMPS
AROUND -6C DOES SKIRT BY TO OUR NORTHEAST BUT STILL EXPECT NEARLY
IDEAL RADIATIVE CONDITIONS WITH CLEAR SKIES AND A LIGHT NORTHERLY
WIND. WILL THEREFORE LEAN TOWARD COOLER GUIDANCE WITH MIN TEMPS IN
THE UPPER 20S TO AROUND 30F...SUPPORTING AREAS OF FROST OVER MOST OF
THE CWA. GROWING SEASON IS NOT YET IN FULL SWING SO NO FROST/FREEZE
HEADLINES NECESSARY. WILL HOWEVER ISSUE AN SPS TO ALERT THOSE WITH
SENSITIVE OUTDOOR VEGETATION.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 414 AM EDT TUE APR 22 2014

LONG TERM FORECAST TRENDING TOWARDS COOLER AND POTENTIALLY WETTER
PERIOD BUT LOW CONFIDENCE AND UNCERTAINTY CONTINUE FOR THE UPCOMING
WEEKEND AND EARLY PART OF NEXT WEEK.

WEDNESDAY WILL BEGIN WITH HIGH PRESSURE OVER THE AREA AND A VERY
COOL START. PLENTY OF INSOLATION DURING FIRST PART OF DAY WILL
HELP TEMPS REBOUND INTO THE 50S MOST AREAS. NAM12 SHOWS LAKE SHADOW
MAKING GOOD INLAND PROGRESS LATE MORNING TO EARLY AFTERNOON. EXPECT
TEMPS IN LAKE SHORE COUNTIES WILL STRUGGLE TO REACH 50 AND NEARBY
INLAND COUNTIES TO CLIMB INTO LOWER TO MID 50S BEFORE BECOMING
STEADY FOR FALLING BACK IN THE AFTERNOON AS MARINE LAYER MOVES
FARTHER INLAND. BETTER MIXING OUTSIDE OF LAKE SHADOW SUGGEST HIGHS
IN THE UPPER 50S TO POSSIBLY LOWER 60S.

MOST MODELS STILL TRYING TO GENERATE SOME LIGHT QPF OVER CENTRAL AND
NW AREAS WED NIGHT WITH DEVELOPING LOW LEVEL JET AND WARM AIR
ADVECTION. FORECAST SOUNDINGS CONTINUE TO SHOW VERY DRY LOWER LEVELS
SO IT WILL BE DIFFICULT TO FULLY SATURATE. WILL CONTINUE WITH
SPRINKLE MENTION FOR NOW AND SEE HOW MUCH MOISTURE RETURN DEVELOPS
FOR POSSIBLE BUMP IN POPS NEXT FEW FORECASTS. BETTER CHANCE FOR RAIN
STILL LOOKS TO BE THURSDAY NIGHT AHEAD OF OCCLUDED FRONT AS LOW
PRESSURE MOVES INTO THE GREAT LAKES. GOOD SHORT WAVE AND ASSOCIATED
LIFT SHOWN BY MODELS WITH BRIEF THETA E AND PWAT SURGE. LIKELY POPS
ON TARGET WITH AMOUNTS OF ONE QUARTER TO POSSIBLY ONE HALF INCH WITH
HEAVIER SHOWERS.

MILD DAY FOLLOWS OCCLUDED FRONT FOR FRIDAY WITH TEMPS SIMILAR TO
THURSDAY AND NEAR OR SLIGHTLY ABOVE NORMAL. SECONDARY FRONT DRIVES
SOUTH FRIDAY NIGHT WITH CHANCE FOR LIGHT SHOWERS. THIS WILL HELP SET
UP A RATHER PRONOUNCED BAROCLINIC ZONE ACROSS INDIANA FOR THE
WEEKEND AND EARLY NEXT WEEK. UPPER AIR PATTERN BECOMES MORE
MERIDIONAL AND BLOCKY WITH STALLED SFC FRONT JUST TO OUR SOUTH. THIS
LOOKS TO KEEP A COOL EASTERLY FLOW IN PLACE AT THE SURFACE LEADING
TO RETURN OF BELOW NORMAL TEMPERATURES. UNCERTAINTY INCREASES THIS
WEEKEND AND EARLY NEXT WEEK FOR POPS SO RELIANCE ON ENSEMBLES AND
BLENDS UNTIL FINER DETAILS CAN BE SORTED OUT.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 134 AM EDT TUE APR 22 2014

SURFACE COLD FRONT IS CURRENTLY APPROACHING THE AREA WITH SCT RAIN
SHOWERS ALONG/AHEAD OF IT. PATCHY BR HAS ALSO BEEN REPORTED AT
SEVERAL SITES IMMEDIATELY ALONG AND AHEAD OF THE FRONT. THESE MVFR
CONDITIONS...POSSIBLY BELOW FUEL ALTERNATE CRITERIA...ARE EXPECTED
TO IMPACT THE TERMINALS THROUGH ROUGHLY 09Z AS THIS FRONT PASSES.
VFR CONDITIONS EXPECTED BY 12Z THOUGH AS HIGH PRESSURE AND DRY AIR
ADVECTION SCOUR OUT LOW LEVEL MOISTURE. MOSTLY CLEAR SKIES
EXPECTED TODAY BUT STRONG PRESSURE GRADIENT AND DECENT MIXING
HEIGHTS WILL LEAD TO GUSTY NORTHWEST WINDS FOR MUCH OF THE DAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 8 PM EDT THIS EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...AGD
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...AGD


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

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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA







000
FXUS63 KIND 220801
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
401 AM EDT TUE APR 22 2014

.UPDATE...

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

&&

.SYNOPSIS...
ISSUED AT 401 AM EDT TUE APR 22 2014

A COLD FRONT WILL BE CLEARING THE AREA AROUND THE START OF THE
FORECAST PERIOD...WITH HIGH PRESSURE BUILDING IN QUICKLY BEHIND
IT. THE HIGH WILL KEEP THINGS DRY THROUGH AT LEAST EARLY
THURSDAY INTO THURSDAY NIGHT...WHEN AN ELONGATED AREA OF LOW PRESSURE
AND ASSOCIATED COLD FRONT WILL MOVE THROUGH THE AREA...BRINGING
SHOWERS AND SOME THUNDERSTORMS TO THE AREA. SOME FROST APPEARS
POSSIBLE TOMORROW NIGHT...BUT TEMPERATURES WILL BE BORDERLINE
ACROSS MUCH OF THE AREA. MODELS SUGGEST A CHANGE BACK TO A COOLER
AND DAMP PATTERN LATER IN THE PERIOD AS A LOW PRESSURE SYSTEM
DROPS INTO THE CENTRAL PORTION OF THE COUNTRY AND BEGINS T0 CUT
OFF.

&&

.NEAR TERM /TODAY/...
ISSUED AT 401 AM EDT TUE APR 22 2014

EXPECT FRONT TO BE ON ITS WAY OUT OF THE AREA AT 12Z...AND PRECIP
HAS BEEN ISOLATED AND VERY LIGHT AT BEST FOR SEVERAL HOURS...SO
CONFIDENT THAT NO POPS WILL BE NECESSARY TODAY. CLEARING LINE IS
ADVANCING STEADILY...AND EXPECT MOST OF THE AREA TO BE CLEAR OR
MOSTLY CLEAR BY MID TO LATE MORNING.

MODEL SOUNDINGS SUGGEST FAIRLY GOOD MIXING TODAY AND SOME WIND
GUSTS UP TO 30 MPH...AND HAVE INCLUDED THIS IN THE GRIDS. GUSTS
WILL DIE DOWN IN TYPICAL DIURNAL FASHION THIS EVENING.

CONSENSUS NUMBERS APPEARED TOO COOL BASED ON UPSTREAM NUMBERS AND
LOW LEVEL THICKNESSES...SO BUMPED UP CLOSER TO A MOS BLEND.

&&

.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
ISSUED AT 401 AM EDT TUE APR 22 2014

MAJORITY OF THE SHORT TERM LOOKS DRY AS HIGH PRESSURE CONTROLS THE
AREA. SOME GUIDANCE WANTS TO DEVELOP SOME PRECIP ACROSS THE
NORTH/NORTHWEST WEDNESDAY NIGHT ASSOCIATED WITH AN AREA OF
MIDLEVEL FRONTOGENESIS...BUT LOW LEVELS REMAIN DRY PER FORECAST
SOUNDINGS AND CONTINUED SURFACE RIDGE PRESENCE. WILL CARRY NO POPS
UNTIL THURSDAY AFTERNOON WHEN THE FRONTAL BOUNDARY APPROACHES.
HIGH END LIKELIES APPEAR WARRANTED WITH THE FRONT AS IS PASSES
THURSDAY EVENING...TAPERING QUICKLY AS THE FRONT PASSES LATE IN
THE OVERNIGHT. K INDEX AND DEEP LAYER SHEAR PROGS SUGGEST
POTENTIAL FOR ORGANIZED CONVECTION...BUT NEAR SURFACE INSTABILITY
IS MINIMAL AND INSTABILITY PROFILES ARE VERY NARROW. SPC DAY 3 SEE
TEXT/5 PERCENT SEVERE PROBS ARE REASONABLE.

MODEL CONSENSUS TEMPS APPEARED A BIT TOO COOL ACROSS THE BOARD ON
HIGHS...SO MOST PERIODS LEANED TOWARD THE WARMER MOS BLEND. MAY
END UP NEEDING FROST ADVISORY HEADLINES FOR PORTIONS OF THE AREA
TOMORROW NIGHT...BUT TEMPERATURES LOOK BORDERLINE AT THE MOMENT
AND WINDS STAY UP A BIT. WILL CARRY SOME FROST IN THE GRIDS BUT
HOLD OFF ON ANY HEADLINES FOR THE TIME BEING.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR THE 220600 TAF ISSUANCE/...
ISSUED AT 1256 AM EDT TUE APR 22 2014

MOSTLY VFR...HOWEVER FIRST TO START OFF THE PERIOD A PERIOD OF MVFR
CEILINGS POSSIBLE THROUGH EARLY THIS MORNING WITH SCATTERED SHOWER
ACTIVITY. MODERATE TO BRISK WINDS WILL OCCUR TODAY...FIRST ALONG THE
FRONT AND THEN POST FRONTAL PASSAGE.

WILL CONTINUE TO OMIT MENTION OF THUNDER AS THERE CURRENTLY IS VERY
LITTLE CONVECTION ON THE RADAR. FOLLOWING THE COLD FRONT MUCH DRIER
AIR WILL SPREAD IN FROM THE NORTHWEST CAUSING RAPID CLEARING BY MID
OR LATE MORNING. WINDS WILL BE BECOMING NORTHWEST AND INCREASING UP
TO 15 KNOTS AND GUSTS TO 25 KNOTS BY 15Z THIS MORNING.

&&

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

&&

$$

SYNOPSIS...NIELD
NEAR TERM...NIELD
SHORT TERM...NIELD
LONG TERM...RYAN
AVIATION...SMF

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIND 220712
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
312 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 935 PM EDT MON APR 21 2014

PATCHES OF LIGHT RAIN CURRENTLY MOVING EAST ACROSS THE AREA AS OLD
SOUTHERN PLAINS UPPER TROUGH SHEARS OUT. COLD FRONT ENTERING
NORTHWEST ILLINOIS AT THIS TIME IS PROGGED BY SHORT TERM MODEL DATA
TO ARRIVE IN THE NORTHWEST ZONES AROUND 220700Z.

LIFT ACROSS THE AREA LOOKS TO REMAIN WEAK WITH ONLY ABOUT 15-20 KTS
OF FLOW AT 850MB. THIS EVENING/S UPPER AIR INDICATES LAPSE RATE ARE
RATHER POOR AS WELL. MAY STILL SEE SOME ACTIVITY DEVELOP IN THE
VICINITY OF THE FRONT LATER TONIGHT...BUT DON/T THINK ANYTHING WILL
BE TOO WIDESPREAD BASED ON ABOVE. WILL DROP POPS BACK INTO THE
CHANCE CATEGORY FOR THE REST OF THE NIGHT.

TEMPERATURES SHOULD REMAIN MILD FOR MOST OF THE NIGHT...BEFORE
TAILING OFF TOWARDS SUNRISE WITH FRONTAL PASSAGE. AT THIS
TIME...DON/T SEE A REASON TO DISAGREE WITH THE LOWS.

PREVIOUS DISCUSSION FOLLOWS.

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /FRIDAY THROUGH MONDAY/...
ISSUED AT 312 AM EDT TUE APR 22 2014

EXTENDED MODEL GUIDANCE COMING INTO BETTER AGREEMENT ON AN UPPER
LEVEL PATTERN CHANGE TAKING PLACE DURING THE EXTENDED...FROM A
PROGRESSIVE ZONAL FLOW TO A MUCH MORE BLOCKY PATTERN ALOFT BY
EARLY NEXT WEEK. THIS WILL RESULT IN A SHIFT TO MORE UNSETTLED AND
LIKELY COOLER WEATHER OVER THE OHIO VALLEY FOR NEXT WEEK.

OCCLUDED LOW PRESSURE WILL BE LOCATED OVER THE GREAT LAKES FRIDAY
MORNING WITH RAIN AND THUNDERSTORMS WITH THE ASSOCIATED BOUNDARY
WELL EAST OF THE FORECAST AREA. ZONAL FLOW IN THE WAKE OF THE
OCCLUDED FRONT AND A RESUMPTION OF LOW LEVEL WARM ADVECTION AND
SOUTHWEST FLOW WILL MAKE FRIDAY THE WARMEST DAY OF THE EXTENDED
WITH TEMPS MAINLY IN THE LOWER/MIDDLE 70S. A TRAILING UPPER WAVE
AND SURFACE LOW WILL PINWHEEL BEHIND THE OCCLUDED LOW FRIDAY NIGHT
AND DROP A SECONDARY FRONT INTO THE REGION. HARD TO JUSTIFY MORE
THAN LOW CHANCE POPS FOCUSED OVER THE NORTHERN COUNTIES FRIDAY
NIGHT WITH MOISTURE LACKING ALONG THE FRONT AND BULK OF THE
FORCING ALOFT REMAINING TO OUR NORTH OVER THE GREAT LAKES.

THE MORE SUBSTANTIAL CHANGE FROM THE PASSAGE OF THE FRONT WILL BE
A SHIFT BACK TO COOLER TEMPERATURES AS CANADIAN HIGH PRESSURE
POKES DOWN INTO THE REGION FOR SATURDAY. AFTER DRY WEATHER
SATURDAY...INCREASINGLY UNSETTLED CONDITIONS DEVELOPING FOR THE
SECOND HALF OF THE WEEKEND AND POTENTIALLY INTO THE FIRST HALF OF
NEXT WEEK. HIGHLY AMPLIFIED BLOCKY FLOW ALOFT DEVELOPING WITH A
SHARPENING UPPER WAVE OVER THE ROCKIES. AS THE UPPER LOW DEEPENS
AND SHIFTS INTO THE HIGH PLAINS...A STRONG SURFACE LOW WILL EJECT
OUT INTO THE PLAINS WITH A WARM FRONT EXTENDING EAST INTO THE OHIO
VALLEY. STILL SOME DIFFERENCES REGARDING WHERE THE WARM FRONT SETS
UP AND THE EVENTUAL TRACK OF THE SURFACE LOW...BUT PRESENCE OF
STRONG HIGH PRESSURE OVER JAMES BAY SUGGESTIVE OF A MORE
SUPPRESSED SOLUTION WITH CENTRAL INDIANA LIKELY REMAINING NORTH OF
THE WARM FRONT. WILL MAINTAIN POPS FROM SATURDAY NIGHT THROUGH THE
END OF THE PERIOD. LEANED TOWARDS COOLER ALLBLEND WITH HIGHS
LARGELY REMAINING IN THE 50S AND LOWER 60S SUNDAY AND MONDAY.

EXTENDED GUIDANCE FAVORING THE UPPER LOW OVER THE PLAINS BECOMING
CUTOFF FROM THE MEAN FLOW AS IT MEANDERS EAST INTO THE OHIO AND
TENNESSEE VALLEYS NEXT WEEK. STRONGLY SUGGESTIVE OF A CLOUDY COOL
DAMP PATTERN TO FINISH OUT THE MONTH.

&&

.AVIATION /DISCUSSION FOR THE 220600 TAF ISSUANCE/...
ISSUED AT 1256 AM EDT TUE APR 22 2014

MOSTLY VFR...HOWEVER FIRST TO START OFF THE PERIOD A PERIOD OF MVFR
CEILINGS POSSIBLE THROUGH EARLY THIS MORNING WITH SCATTERED SHOWER
ACTIVITY. MODERATE TO BRISK WINDS WILL OCCUR TODAY...FIRST ALONG THE
FRONT AND THEN POST FRONTAL PASSAGE.

WILL CONTINUE TO OMIT MENTION OF THUNDER AS THERE CURRENTLY IS VERY
LITTLE CONVECTION ON THE RADAR. FOLLOWING THE COLD FRONT MUCH DRIER
AIR WILL SPREAD IN FROM THE NORTHWEST CAUSING RAPID CLEARING BY MID
OR LATE MORNING. WINDS WILL BE BECOMING NORTHWEST AND INCREASING UP
TO 15 KNOTS AND GUSTS TO 25 KNOTS BY 15Z THIS MORNING.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM....RYAN
AVIATION...SMF

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIWX 220534
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
134 AM EDT TUE APR 22 2014

.SYNOPSIS...
ISSUED AT 817 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS EVENING BRINGING
A CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM. MUCH COOLER AND
DRY WEATHER WILL FOLLOW FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN. LOWS TONIGHT WILL FALL BACK INTO THE 40S WITH HIGHS ON
TUESDAY IN THE 50S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

SLOWLY INTENSIFYING LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EAST
ACROSS THE GRTLKS TONIGHT. >1" PRECIP WATER MOISTURE PLUME EXTENDING
N-NE THROUGH THE MS VALLEY INTO THE UPR GRTLKS AHEAD OF THIS SYSTEM
AND ITS ASSOCIATED CDFNT. COMBINATION OF THE DEEP MOISTURE AND
MODEST LIFT ASSOCIATED WITH THE APCHG SHRTWV/CDFNT RESULTING IN
NUMEROUS SHOWERS FROM WI TO OK/ARK EARLY THIS AFTN WHICH SHOULD
SPREAD EAST ACROSS OUR CWA TONIGHT. A FEW LIGHTNING STRIKES NOTED
UPSTREAM OVER IL/IA THIS AFTN WHERE MUCAPES GENERALLY 500-1000J/KG
AND WITH MODELS FCSTG THIS WK INSTABILITY TO TRANSLATE EAST ACROSS
OUR AREA TONIGHT... ISOLATED THUNDERSTORMS STILL PSBL ACROSS OUR
AREA THROUGH TONIGHT. STRONG CAA WILL OVERSPREAD THE CWA BEHIND THE
CDFNT LATE TONIGHT AND TUE... ENHANCED BY ONSHORE FLOW OFF LAKE
MICHIGAN. TEMPS BY TUE MORNING EXPECTED TO FALL INTO THE U30S NW TO
THE L50S SE. SUBSIDENCE/DRYING SHOULD ALLOW FOR MOSTLY SUNNY SKIES
TUE... BUT TEMPS SHOULD BE SLOW TO RESPOND WITH ONLY A 5-10F DIURNAL
RISE RESULTING IN HIGHS 20-30F COLDER THAN TODAY WITH BRISK NW WINDS
ADDING TO THE CHILL.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

PROGRESSIVE, MORE AMPLIFIED, LONGWAVE PATTERN WILL CONTINUE MID-LATE
WEEK. REBOUNDING HEIGHTS ALOFT BEHIND TUESDAY`S MID LEVEL TROUGH
WILL ALLOW A LOW LEVEL RIDGE AXIS TO BUILD IN TUESDAY NIGHT INTO
WEDNESDAY. DRY CP AIRMASS, NOTHING MORE THAN SOME HIGH CIRRUS, AND
WINDS BECOMING LIGHT/VARIABLE WILL LIKELY SUPPORT OPTIMAL
RADIATIONAL COOLING WITH LOWS NEAR FREEZING. WEDNESDAY`S HIGH TEMPS
SHOULD BE A COUPLE DEGREES WARMER WHEN COMPARED TO TUESDAY...WITH
MIXING TO NEAR 850 MB SUPPORTING UPPER 50S-LOW 60S HIGHS AWAY FROM
LAKE SHADOW...ALTHOUGH GRADUAL INCREASE IN MID-HIGH CLOUDS COULD
LIMIT TEMP RISES SOMEWHAT.

MODELS REMAIN IN GOOD AGREEMENT IN TRANSLATING THE NEXT AMPLIFIED
NORTHEAST PACIFIC UPPER TROUGH EAST INTO THE INTERMOUNTAIN WEST
WEDNESDAY AND CENTRAL US THURSDAY. SHORTWAVE/JET ENERGY ROUNDING THE
BASE OF THIS TROUGH NORTHEAST INTO THE MID/UPPER MS VALLEY BY LATER
THURSDAY WILL EVENTUALLY HELP CARVE OUT A VERTICALLY
STACKED/OCCLUDED SYSTEM OVER THE NORTHERN LAKES BY FRIDAY. BULK OF
SHOWER ACTIVITY IN ISENTROPIC/WAA WING OF THIS APPROACHING SYSTEM
SHOULD PASS WEST OF THE IWX CWA LATE WEDNESDAY AFTERNOON INTO
THURSDAY MORNING GIVEN DRY LOW LEVELS. MAYBE A FEW SPRINKLES AT BEST
ACROSS OUR NORTHWEST ZONES. OTHERWISE...RETURN FLOW ON BACKSIDE OF
HIGH PRESSURE SHOULD ENSURE A SOLID WARM UP WED NIGHT/THU. RAIN
CHANCES INCREASE LATER THURSDAY AFTN-EVE GIVEN MODEST LOW LEVEL
MOISTURE SURGE AND RESPECTABLE MID LVL PV ADVECTION/UPPER LEVEL
DIFFLUENCE ALONG THE SFC OCCLUSION. DRY SLOT WITH NEGATIVE HEIGHT
ANOMALY EMERGING OVER THE NORTHER LAKES SHOULD ENSURE A MAINLY
DRY/SEASONABLY MILD/BREEZY FRIDAY. A STRONGER SECONDARY COLD FRONT
WITH PV FILAMENT ROTATING AROUND THE PRIMARY UPPER LOW SHOULD DROP
THROUGH THE AREA LATER FRIDAY AFTERNOON-FRIDAY EVENING MAINTAINING A
LOW CHANCE FOR SHOWERS DURING THIS TIME.

CONFIDENCE IN ANY MODEL SOLUTION REMAINS VERY LOW THIS WEEKEND INTO
EARLY NEXT AS INCREASED HIGH LATITUDE BLOCKING LEAVES SLOW MOVING
(ALMOST CUT-OFF) MID TROPOSPHERIC CIRCULATIONS INVOF THE CENTRAL
HIGHS PLAINS AND ANOTHER OVER THE NORTHEAST US/SE CANADA. IN
BETWEEN...SFC HIGH PRESSURE WILL ATTEMPT TO NUDGE SOUTH INTO THE
GREAT LAKES REGION...WITH THE GFS AND MANY OF ITS MEMBERS (12Z ECMWF
ALSO TRENDING THIS WAY) KEEPING AN ACTIVE BAROCLINIC ZONE SOUTH AND
WEST OF THE LOCAL AREA FOR MUCH OF THE SATURDAY-MONDAY PERIOD. GIVEN
LOW CONFIDENCE AND 12Z ECMWF TRENDS FELT PERSISTENCE (A MAINLY DRY
OPTIMISTIC FCST) WAS THE WAY TO GO THIS WEEKEND. OTHERWISE...EXPECT
BELOW NORMAL TEMPS SAT-MON.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 134 AM EDT TUE APR 22 2014

SURFACE COLD FRONT IS CURRENTLY APPROACHING THE AREA WITH SCT RAIN
SHOWERS ALONG/AHEAD OF IT. PATCHY BR HAS ALSO BEEN REPORTED AT
SEVERAL SITES IMMEDIATELY ALONG AND AHEAD OF THE FRONT. THESE MVFR
CONDITIONS...POSSIBLY BELOW FUEL ALTERNATE CRITERIA...ARE EXPECTED
TO IMPACT THE TERMINALS THROUGH ROUGHLY 09Z AS THIS FRONT PASSES.
VFR CONDITIONS EXPECTED BY 12Z THOUGH AS HIGH PRESSURE AND DRY AIR
ADVECTION SCOUR OUT LOW LEVEL MOISTURE. MOSTLY CLEAR SKIES
EXPECTED TODAY BUT STRONG PRESSURE GRADIENT AND DECENT MIXING
HEIGHTS WILL LEAD TO GUSTY NORTHWEST WINDS FOR MUCH OF THE DAY.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 8 PM EDT THIS
     EVENING FOR LMZ043-046.

&&

$$

SYNOPSIS...CEO/T
SHORT TERM...JT
LONG TERM...STEINWEDEL
AVIATION...AGD


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

FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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000
FXUS63 KIND 220456
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1256 AM EDT TUE APR 22 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 935 PM EDT MON APR 21 2014

PATCHES OF LIGHT RAIN CURRENTLY MOVING EAST ACROSS THE AREA AS OLD
SOUTHERN PLAINS UPPER TROUGH SHEARS OUT. COLD FRONT ENTERING
NORTHWEST ILLINOIS AT THIS TIME IS PROGGED BY SHORT TERM MODEL DATA
TO ARRIVE IN THE NORTHWEST ZONES AROUND 220700Z.

LIFT ACROSS THE AREA LOOKS TO REMAIN WEAK WITH ONLY ABOUT 15-20 KTS
OF FLOW AT 850MB. THIS EVENING/S UPPER AIR INDICATES LAPSE RATE ARE
RATHER POOR AS WELL. MAY STILL SEE SOME ACTIVITY DEVELOP IN THE
VICINITY OF THE FRONT LATER TONIGHT...BUT DON/T THINK ANYTHING WILL
BE TOO WIDESPREAD BASED ON ABOVE. WILL DROP POPS BACK INTO THE
CHANCE CATEGORY FOR THE REST OF THE NIGHT.

TEMPERATURES SHOULD REMAIN MILD FOR MOST OF THE NIGHT...BEFORE
TAILING OFF TOWARDS SUNRISE WITH FRONTAL PASSAGE. AT THIS
TIME...DON/T SEE A REASON TO DISAGREE WITH THE LOWS.

PREVIOUS DISCUSSION FOLLOWS.

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEE EM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 220600 TAF ISSUANCE/...
ISSUED AT 1256 AM EDT TUE APR 22 2014

MOSTLY VFR...HOWEVER FIRST TO START OFF THE PERIOD A PERIOD OF MVFR
CEILINGS POSSIBLE THROUGH EARLY THIS MORNING WITH SCATTERED SHOWER
ACTIVITY. MODERATE TO BRISK WINDS WILL OCCUR TODAY...FIRST ALONG THE
FRONT AND THEN POST FRONTAL PASSAGE.

WILL CONTINUE TO OMIT MENTION OF THUNDER AS THERE CURRENTLY IS VERY
LITTLE CONVECTION ON THE RADAR. FOLLOWING THE COLD FRONT MUCH DRIER
AIR WILL SPREAD IN FROM THE NORTHWEST CAUSING RAPID CLEARING BY MID
OR LATE MORNING. WINDS WILL BE BECOMING NORTHWEST AND INCREASING UP
TO 15 KNOTS AND GUSTS TO 25 KNOTS BY 15Z THIS MORNING.

&&

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

&&

$$

SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM...JH
AVIATION...SMF

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIND 220219
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1019 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 935 PM EDT MON APR 21 2014

PATCHES OF LIGHT RAIN CURRENTLY MOVING EAST ACROSS THE AREA AS OLD
SOUTHERN PLAINS UPPER TROUGH SHEARS OUT. COLD FRONT ENTERING
NORTHWEST ILLINOIS AT THIS TIME IS PROGGED BY SHORT TERM MODEL DATA
TO ARRIVE IN THE NORTHWEST ZONES AROUND 220700Z.

LIFT ACROSS THE AREA LOOKS TO REMAIN WEAK WITH ONLY ABOUT 15-20 KTS
OF FLOW AT 850MB. THIS EVENING/S UPPER AIR INDICATES LAPSE RATE ARE
RATHER POOR AS WELL. MAY STILL SEE SOME ACTIVITY DEVELOP IN THE
VICINITY OF THE FRONT LATER TONIGHT...BUT DON/T THINK ANYTHING WILL
BE TOO WIDESPREAD BASED ON ABOVE. WILL DROP POPS BACK INTO THE
CHANCE CATEGORY FOR THE REST OF THE NIGHT.

TEMPERATURES SHOULD REMAIN MILD FOR MOST OF THE NIGHT...BEFORE
TAILING OFF TOWARDS SUNRISE WITH FRONTAL PASSAGE. AT THIS
TIME...DON/T SEE A REASON TO DISAGREE WITH THE LOWS.

PREVIOUS DISCUSSION FOLLOWS.

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEE EM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 220000 TAF ISSUANCE/...

ISSUED AT 1018 PM EDT MON APR 21 2014

0215Z UPDATE...NO CHANGES NEEDED AT THIS TIME. PREVIOUS DISCUSSION
FOLLOWS.

MOSTLY VFR...HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY ALONG A COLD FRONT AND POST FRONTAL PASSAGE.

SCATTERED SHOWERS WILL INCREASE ACROSS OUR REGION EARLY TONIGHT.
WILL GO WITH PREVAILING SHOWERS...BUT SINCE MUCH OF THE CONVECTIVE
ACTIVITY HAS ABATED UPSTREAM HAVE OPTED TO REMOVE VCTS AND CB
GROUPS AT THIS TIME. MODELS INDICATE MVFR CEILINGS WILL OCCUR ALONG
AND JUST BEHIND FRONT AS SHOWERS INCREASE ALONG THE COLD FRONT
OVERNIGHT. AND THIS HAS BEEN ACCOUNTED FOR IN THE TAFS.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. SOUTHWEST WINDS
WILL BE DECREASING A LITTLE THIS EVENING AND THEN BECOMING
NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS TO 25 KNOTS
TUESDAY MORNING.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM...JH
AVIATION...SMF

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

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








000
FXUS63 KIND 220138
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
935 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...
ISSUED AT 935 PM EDT MON APR 21 2014

PATCHES OF LIGHT RAIN CURRENTLY MOVING EAST ACROSS THE AREA AS OLD
SOUTHERN PLAINS UPPER TROUGH SHEARS OUT. COLD FRONT ENTERING
NORTHWEST ILLINOIS AT THIS TIME IS PROGGED BY SHORT TERM MODEL DATA
TO ARRIVE IN THE NORTHWEST ZONES AROUND 220700Z.

LIFT ACROSS THE AREA LOOKS TO REMAIN WEAK WITH ONLY ABOUT 15-20 KTS
OF FLOW AT 850MB. THIS EVENING/S UPPER AIR INDICATES LAPSE RATE ARE
RATHER POOR AS WELL. MAY STILL SEE SOME ACTIVITY DEVELOP IN THE
VICINITY OF THE FRONT LATER TONIGHT...BUT DON/T THINK ANYTHING WILL
BE TOO WIDESPREAD BASED ON ABOVE. WILL DROP POPS BACK INTO THE
CHANCE CATEGORY FOR THE REST OF THE NIGHT.

TEMPERATURES SHOULD REMAIN MILD FOR MOST OF THE NIGHT...BEFORE
TAILING OFF TOWARDS SUNRISE WITH FRONTAL PASSAGE. AT THIS
TIME...DON/T SEE A REASON TO DISAGREE WITH THE LOWS.

PREVIOUS DISCUSSION FOLLOWS.

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEEEM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 220000 TAF ISSUANCE/...

ISSUED AT 701 PM EDT MON APR 21 2014

MOSTLY VFR...HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY ALONG A COLD FRONT AND POST FRONTAL PASSAGE.

SCATTERED SHOWERS WILL INCREASE ACROSS OUR REGION EARLY TONIGHT.
WILL GO WITH PREVAILING SHOWERS...BUT SINCE MUCH OF THE CONVECTIVE
ACTIVITY HAS ABATED UPSTREAM HAVE OPTED TO REMOVE VCTS AND CB
GROUPS AT THIS TIME. MODELS INDICATE MVFR CEILINGS WILL OCCUR ALONG
AND JUST BEHIND FRONT AS SHOWERS INCREASE ALONG THE COLD FRONT
OVERNIGHT. AND THIS HAS BEEN ACCOUNTED FOR IN THE TAFS.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. SOUTHWEST WINDS
WILL BE DECREASING A LITTLE THIS EVENING AND THEN BECOMING
NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS TO 25 KNOTS
TUESDAY MORNING.

&&

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

$$

SYNOPSIS...CP
NEAR TERM...CP/JAS
SHORT TERM...CP
LONG TERM...JH
AVIATION...SMF

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
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000
FXUS63 KIWX 220017
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
817 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 817 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE ACROSS THE AREA LATE THIS EVENING BRINGING
A CHANCE FOR SHOWERS AND AN ISOLATED THUNDERSTORM. MUCH COOLER AND
DRY WEATHER WILL FOLLOW FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN. LOWS TONIGHT WILL FALL BACK INTO THE 40S WITH HIGHS ON
TUESDAY IN THE 50S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

SLOWLY INTENSIFYING LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EAST
ACROSS THE GRTLKS TONIGHT. >1" PRECIP WATER MOISTURE PLUME EXTENDING
N-NE THROUGH THE MS VALLEY INTO THE UPR GRTLKS AHEAD OF THIS SYSTEM
AND ITS ASSOCIATED CDFNT. COMBINATION OF THE DEEP MOISTURE AND
MODEST LIFT ASSOCIATED WITH THE APCHG SHRTWV/CDFNT RESULTING IN
NUMEROUS SHOWERS FROM WI TO OK/ARK EARLY THIS AFTN WHICH SHOULD
SPREAD EAST ACROSS OUR CWA TONIGHT. A FEW LIGHTNING STRIKES NOTED
UPSTREAM OVER IL/IA THIS AFTN WHERE MUCAPES GENERALLY 500-1000J/KG
AND WITH MODELS FCSTG THIS WK INSTABILITY TO TRANSLATE EAST ACROSS
OUR AREA TONIGHT... ISOLATED THUNDERSTORMS STILL PSBL ACROSS OUR
AREA THROUGH TONIGHT. STRONG CAA WILL OVERSPREAD THE CWA BEHIND THE
CDFNT LATE TONIGHT AND TUE... ENHANCED BY ONSHORE FLOW OFF LAKE
MICHIGAN. TEMPS BY TUE MORNING EXPECTED TO FALL INTO THE U30S NW TO
THE L50S SE. SUBSIDENCE/DRYING SHOULD ALLOW FOR MOSTLY SUNNY SKIES
TUE... BUT TEMPS SHOULD BE SLOW TO RESPOND WITH ONLY A 5-10F DIURNAL
RISE RESULTING IN HIGHS 20-30F COLDER THAN TODAY WITH BRISK NW WINDS
ADDING TO THE CHILL.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

PROGRESSIVE, MORE AMPLIFIED, LONGWAVE PATTERN WILL CONTINUE MID-LATE
WEEK. REBOUNDING HEIGHTS ALOFT BEHIND TUESDAY`S MID LEVEL TROUGH
WILL ALLOW A LOW LEVEL RIDGE AXIS TO BUILD IN TUESDAY NIGHT INTO
WEDNESDAY. DRY CP AIRMASS, NOTHING MORE THAN SOME HIGH CIRRUS, AND
WINDS BECOMING LIGHT/VARIABLE WILL LIKELY SUPPORT OPTIMAL
RADIATIONAL COOLING WITH LOWS NEAR FREEZING. WEDNESDAY`S HIGH TEMPS
SHOULD BE A COUPLE DEGREES WARMER WHEN COMPARED TO TUESDAY...WITH
MIXING TO NEAR 850 MB SUPPORTING UPPER 50S-LOW 60S HIGHS AWAY FROM
LAKE SHADOW...ALTHOUGH GRADUAL INCREASE IN MID-HIGH CLOUDS COULD
LIMIT TEMP RISES SOMEWHAT.

MODELS REMAIN IN GOOD AGREEMENT IN TRANSLATING THE NEXT AMPLIFIED
NORTHEAST PACIFIC UPPER TROUGH EAST INTO THE INTERMOUNTAIN WEST
WEDNESDAY AND CENTRAL US THURSDAY. SHORTWAVE/JET ENERGY ROUNDING THE
BASE OF THIS TROUGH NORTHEAST INTO THE MID/UPPER MS VALLEY BY LATER
THURSDAY WILL EVENTUALLY HELP CARVE OUT A VERTICALLY
STACKED/OCCLUDED SYSTEM OVER THE NORTHERN LAKES BY FRIDAY. BULK OF
SHOWER ACTIVITY IN ISENTROPIC/WAA WING OF THIS APPROACHING SYSTEM
SHOULD PASS WEST OF THE IWX CWA LATE WEDNESDAY AFTERNOON INTO
THURSDAY MORNING GIVEN DRY LOW LEVELS. MAYBE A FEW SPRINKLES AT BEST
ACROSS OUR NORTHWEST ZONES. OTHERWISE...RETURN FLOW ON BACKSIDE OF
HIGH PRESSURE SHOULD ENSURE A SOLID WARM UP WED NIGHT/THU. RAIN
CHANCES INCREASE LATER THURSDAY AFTN-EVE GIVEN MODEST LOW LEVEL
MOISTURE SURGE AND RESPECTABLE MID LVL PV ADVECTION/UPPER LEVEL
DIFFLUENCE ALONG THE SFC OCCLUSION. DRY SLOT WITH NEGATIVE HEIGHT
ANOMALY EMERGING OVER THE NORTHER LAKES SHOULD ENSURE A MAINLY
DRY/SEASONABLY MILD/BREEZY FRIDAY. A STRONGER SECONDARY COLD FRONT
WITH PV FILAMENT ROTATING AROUND THE PRIMARY UPPER LOW SHOULD DROP
THROUGH THE AREA LATER FRIDAY AFTERNOON-FRIDAY EVENING MAINTAINING A
LOW CHANCE FOR SHOWERS DURING THIS TIME.

CONFIDENCE IN ANY MODEL SOLUTION REMAINS VERY LOW THIS WEEKEND INTO
EARLY NEXT AS INCREASED HIGH LATITUDE BLOCKING LEAVES SLOW MOVING
(ALMOST CUT-OFF) MID TROPOSPHERIC CIRCULATIONS INVOF THE CENTRAL
HIGHS PLAINS AND ANOTHER OVER THE NORTHEAST US/SE CANADA. IN
BETWEEN...SFC HIGH PRESSURE WILL ATTEMPT TO NUDGE SOUTH INTO THE
GREAT LAKES REGION...WITH THE GFS AND MANY OF ITS MEMBERS (12Z ECMWF
ALSO TRENDING THIS WAY) KEEPING AN ACTIVE BAROCLINIC ZONE SOUTH AND
WEST OF THE LOCAL AREA FOR MUCH OF THE SATURDAY-MONDAY PERIOD. GIVEN
LOW CONFIDENCE AND 12Z ECMWF TRENDS FELT PERSISTENCE (A MAINLY DRY
OPTIMISTIC FCST) WAS THE WAY TO GO THIS WEEKEND. OTHERWISE...EXPECT
BELOW NORMAL TEMPS SAT-MON.

&&

.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 817 PM EDT MON APR 21 2014

GENERAL VFR CONDS XPCD FOR MOST OF THE PD OUTSIDE TEMPO MVFR CONDS IN
SHRA THIS EVENING INADV OF EWD TRANSLATING SFC CDFNT AND UPSTREAM SW
TROUGH SHEARING NEWD OUT OF CNTRL IL. BULK OF ACTIVITY SO FAR HAS
BEEN CONCENTRATED ON NOSE OF LLJ/LL THETA-E BULGE ACRS NE IL/NW IN
YET XPC THAT WILL SHIFT SEWD THROUGH THIS EVENING. OTRWS VIGOROUS LL
CAA WILL WRAP IN BEHIND FROPA AND YIELD GUSTY WINDS FOR MUCH OF TUE
W/SFC GUSTS AOA 25KTS.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY FROM 6 AM TO 8 PM EDT TUESDAY FOR LMZ043-
     046.

&&

$$

SYNOPSIS...CEO/T
SHORT TERM...JT
LONG TERM...STEINWEDEL
AVIATION...T


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

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







000
FXUS63 KIND 212321
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
721 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 358 PM EDT MON APR 21 2014

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEEEM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 220000 TAF ISSUANCE/...

ISSUED AT 701 PM EDT MON APR 21 2014

MOSTLY VFR...HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY ALONG A COLD FRONT AND POST FRONTAL PASSAGE.

SCATTERED SHOWERS WILL INCREASE ACROSS OUR REGION EARLY TONIGHT.
WILL GO WITH PREVAILING SHOWERS...BUT SINCE MUCH OF THE CONVECTIVE
ACTIVITY HAS ABATED UPSTREAM HAVE OPTED TO REMOVE VCTS AND CB
GROUPS AT THIS TIME. MODELS INDICATE MVFR CEILINGS WILL OCCUR ALONG
AND JUST BEHIND FRONT AS SHOWERS INCREASE ALONG THE COLD FRONT
OVERNIGHT. AND THIS HAS BEEN ACCOUNTED FOR IN THE TAFS.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. SOUTHWEST WINDS
WILL BE DECREASING A LITTLE THIS EVENING AND THEN BECOMING
NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS TO 25 KNOTS
TUESDAY MORNING.

&&

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

$$

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

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

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








000
FXUS63 KIND 212035
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
435 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 358 PM EDT MON APR 21 2014

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEEEM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 211800Z TAF ISSUANCE/...

ISSUED AT 432 PM EDT MON APR 21 2014

2030Z UPDATE...NO CHANGES AT THIS TIME. THOUGHT ABOUT ADDING -SHRA
BUT PER OBS THINK THE BULK OF THESE RETURNS ARE NOT REACHING THE
SURFACE...YET. PREVIOUS DISCUSSION FOLLOWS.

MOSTLY VFR. HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY.

LOW PRESSURE OVER NORTHERN LAKE MICHIGAN AND A TRAILING COLD FRONT
ACROSS EASTERN IOWA WILL MOVE SOUTHEAST ACROSS OUR REGION DURING THE
MIDDLE AND LATER PARTS OF TONIGHT.  VFR CONDITIONS WILL CONTINUE
THIS AFTERNOON. HOWEVER SCATTERED SHOWERS AND AN ISOLATED
THUNDERSHOWER WILL INCREASE ACROSS OUR REGION LATE THIS AFTERNOON
AND EARLY TONIGHT. WILL GO WITH PREVAILING SHOWERS AND VCTS
BEGINNING AT MOST SITES AROUND 00Z-02Z TIME PERIOD. MODELS INDICATE
MVFR CEILINGS MAY OCCUR ALONG AND JUST BEHIND FRONT AS SHOWERS
INCREASE ALONG THE COLD FRONT OVERNIGHT.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. WINDS THIS AFTERNOON
WILL BE SOUTHWEST 10 TO 12 KNOTS DECREASING A LITTLE THIS EVENING
AND THEN BECOMING NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS
TO 25 KNOTS TUESDAY MORNING.

&&

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

$$

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

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

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








000
FXUS63 KIND 212000
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
400 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 358 PM EDT MON APR 21 2014

A COLD FRONT WILL MOVE THROUGH LATE TONIGHT AND THIS WILL KEEP
CHANCES FOR RAIN AND ISOLATED THUNDERSTORMS IN THE FORECAST
THROUGH THE NIGHT. HIGH PRESSURE WILL USHER IN DRY WEATHER TUESDAY
INTO THURSDAY. COLD TEMPERATURES TUESDAY NIGHT COULD LEAD TO SOME
FROST. ANOTHER FRONTAL PASSAGE THURSDAY NIGHT WILL BRING MORE
THUNDERSTORM CHANCES AND COOLER WEATHER IN ITS WAKE.


&&

.NEAR TERM /TONIGHT/...

ISSUED AT 358 PM EDT MON APR 21 2014

FORECAST FOCUS IS ON POPS AND TIMING WITH FRONTAL SYSTEM TONIGHT.
MODELS ARE IN GOOD AGREEMENT AND WILL USE A CONSENSUS.

AT 19Z WSR88D SHOWED A FEW ECHOES ACROSS THE NORTHWEST PART OF THE
AREA...BUT AS OF YET NO OBSERVED RAIN AT THE GROUND WITH DEW POINTS
STILL IN THE MID 40S TO AROUND 50 AND TEMPERATURES IN THE 70S. THE
COLD FRONT WAS GETTING INTO WESTERN ILLINOIS AND A FEW THUNDERSTORMS
WERE ACROSS NORTHERN ILLINOIS WITH SCATTERED SHOWERS IN CENTRAL
ILLINOIS AND KENTUCKY. WITH THE DRY DEW POINTS IT IS TAKING SOME
TIME FOR THE COLUMN TO SATURATE.

THE BEST FORCING WILL REMAIN ALONG/JUST AHEAD OF THE COLD FRONT
TONIGHT. WITH SOME INSTABILITY AROUND WILL CONTINUE TO INCLUDE
ISOLATED THUNDER. BROUGHT LIKELY POPS INTO THE NORTHWEST BY 0Z AND
OVERSPREAD THE AREA THROUGH 3Z WITH DECREASING POPS IN THE NORTHWEST
BY 12Z. ALSO HI RES MODELS SHOW FRONTAL FORCING DECREASING WITH TIME
SO DROPPED TO ONLY CHANCE POPS IN THE SOUTHEAST BY 9Z EVEN WITH THE
FRONT STILL MOVING THROUGH.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...

ISSUED AT 358 PM EDT MON APR 21 2014

BY TUESDAY MORNING 12Z THE COLD FRONT SHOULD BE THROUGH THE AREA AND
CLOUDS SHOULD START CLEARING OUT FROM THE NORTHWEST. CLEARING WILL
LAG FRONTAL PASSAGE BY A BIT BUT BY MIDDAY SHOULD SEE MOST OF THE
CLOUD COVER MOVING OUT OF THE AREA. FOR TEMPERATURES USED AN AVERAGE
WITH MOS BEING CLOSE.

FORECAST FOCUS IS ON LOW TEMPERATURES ON TUESDAY NIGHT. TIME HEIGHTS
AND UPSTREAM LOCATION OF UPPER RIDGE AXIS INDICATE SOME POTENTIAL
FOR CIRRUS TUESDAY NIGHT. SURFACE HIGH PRESSURE WILL STILL BE
BUILDING IN FROM THE NORTH SO PRESSURE GRADIENT NEVER QUITE GOES
SLACK WHICH SHOULD ALLOW WINDS TO STAY AROUND 5 KTS OR SO AND NOT GO
CALM. THESE CONDITIONS DO NOT LINE UP FOR IDEAL RADIATIONAL COOLING
SO PREFER TO STICK CLOSER TO THE WARMER MAV GUIDANCE NUMBERS WITH
LOWS FROM 33 TO THE UPPER 30S. THE WIND COULD ALSO HELP SOMEWHAT
DECREASE THE POTENTIAL FOR FROST FORMATION...BUT THIS WILL STILL BE
A CLOSE CALL. FOR NOW WILL ADD PATCHY FROST TO THE FORECAST BUT IF
WINDS LOOK LIGHTER IN SUBSEQUENT FORECASTS WILL HAVE TO BEEF UP
COVERAGE AND POTENTIALLY GO WITH A HEADLINE.

THE REST OF THE SHORT TERM WILL BE PRETTY QUIET UNDER HIGH PRESSURE.
USED AN AVERAGE OF MOS FOR HIGHS AND LOWS. NEXT CHANCE FOR
THUNDERSTORMS MOVES IN THURSDAY AFTERNOON AS A COLD FRONT MOVES INTO
THE NORTHWEST BY AROUND 0Z FRIDAY.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEEEM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 21/18Z TAF ISSUANCE/...
ISSUED AT 100 PM EDT MON APR 21 2014

MOSTLY VFR. HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY.

LOW PRESSURE OVER NORTHERN LAKE MICHIGAN AND A TRAILING COLD FRONT
ACROSS EASTERN IOWA WILL MOVE SOUTHEAST ACROSS OUR REGION DURING THE
MIDDLE AND LATER PARTS OF TONIGHT.  VFR CONDITIONS WILL CONTINUE
THIS AFTERNOON. HOWEVER SCATTERED SHOWERS AND AN ISOLATED
THUNDERSHOWER WILL INCREASE ACROSS OUR REGION LATE THIS AFTERNOON
AND EARLY TONIGHT. WILL GO WITH PREVAILING SHOWERS AND VCTS
BEGINNING AT MOST SITES AROUND 00Z-02Z TIME PERIOD. MODELS INDICATE
MVFR CEILINGS MAY OCCUR ALONG AND JUST BEHIND FRONT AS SHOWERS
INCREASE ALONG THE COLD FRONT OVERNIGHT.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. WINDS THIS AFTERNOON
WILL BE SOUTHWEST 10 TO 12 KNOTS DECREASING A LITTLE THIS EVENING
AND THEN BECOMING NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS
TO 25 KNOTS TUESDAY MORNING.


&&

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

$$

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

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

FOLLOW US ON TWITTER AND YOUTUBE AT:
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000
FXUS63 KIWX 211942 CCA
AFDIWX

AREA FORECAST DISCUSSION...CORRECTION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
341 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 1215 PM EDT MON APR 21 2014

TEMPERATURES WILL CLIMB INTO THE MID TO UPPER 70S THIS AFTERNOON
AHEAD OF A COLD FRONT THAT WILL MOVE ACROSS THE AREA OVERNIGHT.
SHOWERS AND ISOLATED THUNDERSTORMS WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO THE OVERNIGHT HOURS. COOLER AND DRIER
WEATHER IS EXPECTED FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN...WITH HIGHS IN THE 50S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

SLOWLY INTENSIFYING LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EAST
ACROSS THE GRTLKS TONIGHT. >1" PRECIP WATER MOISTURE PLUME EXTENDING
N-NE THROUGH THE MS VALLEY INTO THE UPR GRTLKS AHEAD OF THIS SYSTEM
AND ITS ASSOCIATED CDFNT. COMBINATION OF THE DEEP MOISTURE AND
MODEST LIFT ASSOCIATED WITH THE APCHG SHRTWV/CDFNT RESULTING IN
NUMEROUS SHOWERS FROM WI TO OK/ARK EARLY THIS AFTN WHICH SHOULD
SPREAD EAST ACROSS OUR CWA TONIGHT. A FEW LIGHTNING STRIKES NOTED
UPSTREAM OVER IL/IA THIS AFTN WHERE MUCAPES GENERALLY 500-1000J/KG
AND WITH MODELS FCSTG THIS WK INSTABILITY TO TRANSLATE EAST ACROSS
OUR AREA TONIGHT... ISOLATED THUNDERSTORMS STILL PSBL ACROSS OUR
AREA THROUGH TONIGHT. STRONG CAA WILL OVERSPREAD THE CWA BEHIND THE
CDFNT LATE TONIGHT AND TUE... ENHANCED BY ONSHORE FLOW OFF LAKE
MICHIGAN. TEMPS BY TUE MORNING EXPECTED TO FALL INTO THE U30S NW TO
THE L50S SE. SUBSIDENCE/DRYING SHOULD ALLOW FOR MOSTLY SUNNY SKIES
TUE... BUT TEMPS SHOULD BE SLOW TO RESPOND WITH ONLY A 5-10F DIURNAL
RISE RESULTING IN HIGHS 20-30F COLDER THAN TODAY WITH BRISK NW WINDS
ADDING TO THE CHILL.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

PROGRESSIVE, MORE AMPLIFIED, LONGWAVE PATTERN WILL CONTINUE MID-LATE
WEEK. REBOUNDING HEIGHTS ALOFT BEHIND TUESDAY`S MID LEVEL TROUGH
WILL ALLOW A LOW LEVEL RIDGE AXIS TO BUILD IN TUESDAY NIGHT INTO
WEDNESDAY. DRY CP AIRMASS, NOTHING MORE THAN SOME HIGH CIRRUS, AND
WINDS BECOMING LIGHT/VARIABLE WILL LIKELY SUPPORT OPTIMAL
RADIATIONAL COOLING WITH LOWS NEAR FREEZING. WEDNESDAY`S HIGH TEMPS
SHOULD BE A COUPLE DEGREES WARMER WHEN COMPARED TO TUESDAY...WITH
MIXING TO NEAR 850 MB SUPPORTING UPPER 50S-LOW 60S HIGHS AWAY FROM
LAKE SHADOW...ALTHOUGH GRADUAL INCREASE IN MID-HIGH CLOUDS COULD
LIMIT TEMP RISES SOMEWHAT.

MODELS REMAIN IN GOOD AGREEMENT IN TRANSLATING THE NEXT AMPLIFIED
NORTHEAST PACIFIC UPPER TROUGH EAST INTO THE INTERMOUNTAIN WEST
WEDNESDAY AND CENTRAL US THURSDAY. SHORTWAVE/JET ENERGY ROUNDING THE
BASE OF THIS TROUGH NORTHEAST INTO THE MID/UPPER MS VALLEY BY LATER
THURSDAY WILL EVENTUALLY HELP CARVE OUT A VERTICALLY
STACKED/OCCLUDED SYSTEM OVER THE NORTHERN LAKES BY FRIDAY. BULK OF
SHOWER ACTIVITY IN ISENTROPIC/WAA WING OF THIS APPROACHING SYSTEM
SHOULD PASS WEST OF THE IWX CWA LATE WEDNESDAY AFTERNOON INTO
THURSDAY MORNING GIVEN DRY LOW LEVELS. MAYBE A FEW SPRINKLES AT BEST
ACROSS OUR NORTHWEST ZONES. OTHERWISE...RETURN FLOW ON BACKSIDE OF
HIGH PRESSURE SHOULD ENSURE A SOLID WARM UP WED NIGHT/THU. RAIN
CHANCES INCREASE LATER THURSDAY AFTN-EVE GIVEN MODEST LOW LEVEL
MOISTURE SURGE AND RESPECTABLE MID LVL PV ADVECTION/UPPER LEVEL
DIFFLUENCE ALONG THE SFC OCCLUSION. DRY SLOT WITH NEGATIVE HEIGHT
ANOMALY EMERGING OVER THE NORTHER LAKES SHOULD ENSURE A MAINLY
DRY/SEASONABLY MILD/BREEZY FRIDAY. A STRONGER SECONDARY COLD FRONT
WITH PV FILAMENT ROTATING AROUND THE PRIMARY UPPER LOW SHOULD DROP
THROUGH THE AREA LATER FRIDAY AFTERNOON-FRIDAY EVENING MAINTAINING A
LOW CHANCE FOR SHOWERS DURING THIS TIME.

CONFIDENCE IN ANY MODEL SOLUTION REMAINS VERY LOW THIS WEEKEND INTO
EARLY NEXT AS INCREASED HIGH LATITUDE BLOCKING LEAVES SLOW MOVING
(ALMOST CUT-OFF) MID TROPOSPHERIC CIRCULATIONS INVOF THE CENTRAL
HIGHS PLAINS AND ANOTHER OVER THE NORTHEAST US/SE CANADA. IN
BETWEEN...SFC HIGH PRESSURE WILL ATTEMPT TO NUDGE SOUTH INTO THE
GREAT LAKES REGION...WITH THE GFS AND MANY OF ITS MEMBERS (12Z ECMWF
ALSO TRENDING THIS WAY) KEEPING AN ACTIVE BAROCLINIC ZONE SOUTH AND
WEST OF THE LOCAL AREA FOR MUCH OF THE SATURDAY-MONDAY PERIOD. GIVEN
LOW CONFIDENCE AND 12Z ECMWF TRENDS FELT PERSISTENCE (A MAINLY DRY
OPTIMISTIC FCST) WAS THE WAY TO GO THIS WEEKEND. OTHERWISE...EXPECT
BELOW NORMAL TEMPS SAT-MON.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1254 PM EDT MON APR 21 2014

AREA SHRA AND ISOLATED TS ASSOCIATED WITH SHRTWV/CDFNT MOVG INTO
THE UPR GRTLKS REGION AND SRN STREAM CIRCULATION EJECTING NE FROM
THE SRN PLAINS WAS MOVG ACROSS SE WI/WRN IL EARLY THIS AFTN AND
SHOULD MOVE ACROSS NRN INDIANA LATE THIS AFTN AND TONIGHT. LOW
LEVELS REMAIN RATHER DRY SO GENERALLY VFR EXPECTED AHEAD OF THE
CDFNT WITH A SHORT PERIOD OF MVFR CIGS IN CAA REGIME BEHIND THE
FRONT BEFORE SKIES CLEAR EARLY TUE. NW WINDS GUSTING TO AROUND
25KT EXPECTED BEHIND THE FRONT LATE TONIGHT AND TUE MORNING.

&&

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

$$

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


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

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










000
FXUS63 KIWX 211939
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
339 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 1215 PM EDT MON APR 21 2014

TEMPERATURES WILL CLIMB INTO THE MID TO UPPER 70S THIS AFTERNOON
AHEAD OF A COLD FRONT THAT WILL MOVE ACROSS THE AREA OVERNIGHT.
SHOWERS AND ISOLATED THUNDERSTORMS WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO THE OVERNIGHT HOURS. COOLER AND DRIER
WEATHER IS EXPECTED FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN...WITH HIGHS IN THE 50S.

&&

.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

SLOWLY INTENSIFYING LOW PRESSURE SYSTEM WILL CONTINUE TO TRACK EAST
ACROSS THE GRTLKS TONIGHT. >1" PRECIP WATER MOISTURE PLUME EXTENDING
N-NE THROUGH THE MS VALLEY INTO THE UPR GRTLKS AHEAD OF THIS SYSTEM
AND ITS ASSOCIATED CDFNT. COMBINATION OF THE DEEP MOISTURE AND
MODEST LIFT ASSOCIATED WITH THE APCHG SHRTWV/CDFNT RESULTING IN
NUMEROUS SHOWERS FROM WI TO OK/ARK EARLY THIS AFTN WHICH SHOULD SPREAD
EAST ACROSS OUR CWA TONIGHT. A FEW LIGHTNING STRIKES NOTED
UPSTREAM OVER IL/IA THIS AFTN WHERE MUCAPES GENERALLY 500-1000J/KG
AND WITH MODELS FCSTG THIS WK INSTABILITY TO TRANSLATE EAST ACROSS
OUR AREA TONIGHT... ISOLATED THUNDERSTORMS STILL PSBL ACROSS OUR
AREA THROUGH TONIGHT. STRONG CAA WILL OVERSPREAD THE CWA BEHIND
THE CDFNT LATE TONIGHT AND TUE... ENHANCED BY ONSHORE FLOW OFF
LAKE MICHIGAN. TEMPS BY TUE MORNING EXPECTED TO FALL INTO THE U30S
NW TO THE L50S SE. SUBSIDENCE/DRYING SHOULD ALLOW FOR MOSTLY SUNNY
SKIES TUE... BUT TEMPS SHOULD BE SLOW TO RESPOND WITH ONLY A 5-10F
DIURNAL RISE RESULTING IN HIGHS 20-30F COLDER THAN TODAY WITH
BRISK NW WINDS ADDING TO THE CHILL.

&&

.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 333 PM EDT MON APR 21 2014

PROGRESSIVE, MORE AMPLIFIED, LONGWAVE PATTERN WILL CONTINUE MID-LATE
WEEK. REBOUNDING HEIGHTS ALOFT BEHIND TUESDAY`S MID LEVEL TROUGH
WILL ALLOW A LOW LEVEL RIDGE AXIS TO BUILD IN TUESDAY NIGHT INTO
WEDNESDAY. DRY CP AIRMASS, NOTHING MORE THAN SOME HIGH CIRRUS, AND
WINDS BECOMING LIGHT/VARIABLE WILL LIKELY SUPPORT OPTIMAL
RADIATIONAL COOLING WITH LOWS NEAR FREEZING. WEDNESDAY`S HIGH TEMPS
SHOULD BE A COUPLE DEGREES WARMER WHEN COMPARED TO TUESDAY...WITH
MIXING TO NEAR 850 MB SUPPORTING UPPER 50S-LOW 60S HIGHS AWAY FROM
LAKE SHADOW...ALTHOUGH GRADUAL INCREASE IN MID-HIGH CLOUDS COULD
LIMIT TEMP RISES SOMEWHAT.

MODELS REMAIN IN GOOD AGREEMENT IN TRANSLATING THE NEXT AMPLIFIED
NORTHEAST PACIFIC UPPER TROUGH EAST INTO THE INTERMOUNTAIN WEST
WEDNESDAY AND CENTRAL US THURSDAY. SHORTWAVE/JET ENERGY ROUNDING THE
BASE OF THIS TROUGH NORTHEAST INTO THE MID/UPPER MS VALLEY BY LATER
THURSDAY WILL EVENTUALLY HELP CARVE OUT A VERTICALLY
STACKED/OCCLUDED SYSTEM OVER THE NORTHERN LAKES BY FRIDAY. BULK OF
SHOWER ACTIVITY IN ISENTROPIC/WAA WING OF THIS APPROACHING SYSTEM
SHOULD PASS WEST OF THE IWX CWA LATE WEDNESDAY AFTERNOON INTO
THURSDAY MORNING GIVEN DRY LOW LEVELS. MAYBE A FEW SPRINKLES AT BEST
ACROSS OUR NORTHWEST ZONES. OTHERWISE...RETURN FLOW ON BACKSIDE OF
HIGH PRESSURE SHOULD ENSURE A SOLID WARM UP WED NIGHT/THU. RAIN
CHANCES INCREASE LATER THURSDAY AFTN-EVE GIVEN MODEST LOW LEVEL
MOISTURE SURGE AND RESPECTABLE MID LVL PV ADVECTION/UPPER LEVEL
DIFFLUENCE ALONG THE SFC OCCLUSION. DRY SLOT WITH NEGATIVE PV
ANOMALY EMERGING OVER THE NORTHER LAKES SHOULD ENSURE A MAINLY
DRY/SEASONABLY MILD/BREEZY FRIDAY. A STRONGER SECONDARY COLD FRONT
WITH PV FILAMENT ROTATING AROUND THE PRIMARY UPPER LOW SHOULD DROP
THROUGH THE AREA LATER FRIDAY AFTERNOON-FRIDAY EVENING MAINTAINING A
LOW CHANCE FOR SHOWERS DURING THIS TIME.

CONFIDENCE IN ANY MODEL SOLUTION REMAINS VERY LOW THIS WEEKEND INTO
EARLY NEXT AS INCREASED HIGH LATITUDE BLOCKING LEAVES SLOW MOVING
(ALMOST CUT-OFF) MID TROPOSPHERIC CIRCULATIONS INVOF THE CENTRAL
HIGHS PLAINS AND ANOTHER OVER THE NORTHEAST US/SE CANADA. IN
BETWEEN...SFC HIGH PRESSURE WILL ATTEMPT TO NUDGE SOUTH INTO THE
GREAT LAKES REGION...WITH THE GFS AND MANY OF ITS MEMBERS (12Z ECMWF
ALSO TRENDING THIS WAY) KEEPING AN ACTIVE BAROCLINIC ZONE SOUTH AND
WEST OF THE LOCAL AREA FOR MUCH OF THE SATURDAY-MONDAY PERIOD. GIVEN
LOW CONFIDENCE AND 12Z ECMWF TRENDS FELT PERSISTENCE (A MAINLY DRY
OPTIMISTIC FCST) WAS THE WAY TO GO THIS WEEKEND. OTHERWISE...EXPECT
BELOW NORMAL TEMPS SAT-MON.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1254 PM EDT MON APR 21 2014

AREA SHRA AND ISOLATED TS ASSOCIATED WITH SHRTWV/CDFNT MOVG INTO
THE UPR GRTLKS REGION AND SRN STREAM CIRCULATION EJECTING NE FROM
THE SRN PLAINS WAS MOVG ACROSS SE WI/WRN IL EARLY THIS AFTN AND
SHOULD MOVE ACROSS NRN INDIANA LATE THIS AFTN AND TONIGHT. LOW
LEVELS REMAIN RATHER DRY SO GENERALLY VFR EXPECTED AHEAD OF THE
CDFNT WITH A SHORT PERIOD OF MVFR CIGS IN CAA REGIME BEHIND THE
FRONT BEFORE SKIES CLEAR EARLY TUE. NW WINDS GUSTING TO AROUND
25KT EXPECTED BEHIND THE FRONT LATE TONIGHT AND TUE MORNING.

&&

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

$$

SYNOPSIS...CEO
SHORT TERM...JT
LONG TERM...STEINWEDEL
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
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000
FXUS63 KIND 211859
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
300 PM EDT MON APR 21 2014

.UPDATE...
LONG TERM SECTION HAS BEEN UPDATED BELOW.

&&

.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 21 2014

SHOWERS WITH EMBEDDED THUNDERSTORMS WILL DEVELOP LATER TODAY AND
CONTINUE TONIGHT AS A COLD FRONT MOVES THROUGH THE OHIO VALLEY.
COOLER DRIER WEATHER RETURNS FOR TUESDAY AND WEDNESDAY AS HIGH
PRESSURE MOVES THROUGH THE REGION. WARMER AND MORE UNSETTLED WEATHER
RETURNS FOR LATE WEEK WITH THE PASSAGE OF ANOTHER COLD FRONT. BEHIND
THE FRONT...COOLER WEATHER WILL RETURN FOR THE WEEKEND.

&&

.NEAR TERM /TODAY/...
ISSUED AT 945 AM EDT MON APR 21 2014

RADAR MOSAIC SHOWS SOME ECHOES OF 20-30 DBZ MOVING INTO KNOX COUNTY
AT 930 AM AND VISIBLE SATELLITE SHOWS A CONVECTIVE NATURE TO THE
CLOUDS ASSOCIATED WITH THESE ECHOES. THUS FAR NO PRECIPITATION HAS
BEEN REPORTED AT THE GROUND UNDER THESE CLOUDS AND WITH DEW POINTS
IN THE MID 40S TO LOW 50S AND A FAIRLY DRY COLUMN THINK CONTINUING
WITH NO MEASURABLE PRECIP TIL AFTER 19Z IS A GOOD IDEA. HOWEVER
CAN/T RULE OUT A FEW SPRINKLES DEVELOPING IN THE SOUTHWEST...SO WILL
GO AHEAD AND ADD A CHANCE FOR SPRINKLES THERE FOR THE NEXT FEW
HOURS. REST OF THE FORECAST IS IN GOOD SHAPE WITH HIGHS IN THE MID
TO UPPER 70S STILL ON TRACK AND HI RES MODELS SHOWING SIMILAR TIMING
TO MEASURABLE PRECIP AS THE GOING FORECAST...AFTER 19Z WITH BEST
CHANCES NOT ARRIVING UNTIL SOMETIME AFTER 0Z.

PREVIOUS DISCUSSION FOLLOWS...

MAIN FOCUS FOR TODAY IS THE APPROACH OF THE UPPER WAVE AND COLD
FRONT TO THE WEST AS LOW PRESSURE OFF THE NORTH CAROLINA COAST
FINALLY SHIFTS FURTHER EAST INTO THE ATLANTIC OCEAN. THIS WILL
ENABLE THE RIDGE AXIS TO LIKEWISE SHIFT EAST TO THE U S EAST COAST
BY LATE DAY. CLOUD COVERAGE WILL INCREASE THROUGHOUT THE DAY AS
MOISTURE ADVECTS INTO THE REGION FROM THE SOUTHWEST. WEAK LIFT AND
FORCING WILL MOVE INTO THE OHIO VALLEY DURING THE COURSE OF THE
AFTERNOON WITH SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM
SPREADING EAST INTO THE FORECAST AREA BY LATE AFTERNOON. MORE
EXPANSIVE COVERAGE TO RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
EVENING AS MODEL SOUNDINGS INDICATING IT WILL TAKE MUCH OF THE DAY
TO MOISTEN THE BOUNDARY LAYER. WILL CARRY MAINLY LOW CHANCE POPS FOR
MID/LATE AFTERNOON.

TEMPS...FILTERED SUN THROUGH THE MORNING AND WARM ADVECTION AHEAD OF
THE FRONT WILL ENABLE ANOTHER WARM DAY PEAKING IN THE 70S. LOW LEVEL
THERMALS SUPPORTED MAX TEMPS AT OR JUST ABOVE MAVMOS IN THE
MID/UPPER 70S.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 21 2014

FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TONIGHT AS THE FRONT
SWINGS THROUGH THE REGION...AND POTENTIAL FOR FROSTY TEMPS WEDNESDAY
MORNING.

WEAKENING UPPER WAVE WILL TRACK THROUGH THE OHIO VALLEY WITH THE
COLD FRONT TONIGHT WITH RAIN SHOWERS AND EMBEDDED THUNDERSTORMS.
MOST WIDESPREAD COVERAGE EXPECTED DURING THE EVENING AND EARLY
OVERNIGHT...WITH PRECIP GRADUALLY SHIFTING INTO THE SOUTHERN/EASTERN
PORTIONS OF THE FORECAST AREA AFTER 06Z TUESDAY. BRIEF PERIOD OF
ISENTROPIC LIFT AND SUBTLE LOW LEVEL CONVERGENCE WITHIN A NARROW
RIBBON OF DEEPER MOISTURE WILL BE THE MAIN RAINFALL CATALYSTS
TONIGHT AND WILL MAINTAIN LIKELY POPS. RAINFALL AMOUNTS WILL BE
GENERALLY LIGHT AT A QUARTER INCH OR LESS.

COLD FRONT WILL BE EAST OF THE FORECAST AREA BY DAYBREAK TUESDAY
WITH THE DEEPER MOISTURE DEPARTING ALONG WITH IT. EXPECT SKIES TO
CLEAR QUICKLY TUESDAY MORNING AS MODEL SOUNDINGS AND RH PROGS
INDICATING A RAPIDLY DRYING COLUMN. DESPITE STRONG COLD ADVECTION
AND A  SHARP WAVE ALOFT PASSING THROUGH THE LOWER GREAT LAKES DURING
THE COURSE OF THE DAY...EXPECT ANY CU FORMATION TO BE SIGNIFICANTLY
LIMITED BY THE INCREASING SUBSIDENCE AND DRY AIR ADVECTING INTO THE
REGION. EFFICIENT LOW LEVEL MIXING WILL BRING STRONGER WINDS TO THE
SURFACE TUESDAY AFTERNOON WITH MAX GUSTS UP TO 25 MPH.

HIGH PRESSURE RIDGE CENTERS ACROSS THE REGION TUESDAY NIGHT WITH
NORTHERLY WINDS BECOMING LIGHT AFTER MIDNIGHT. WITH CLEAR
SKIES...GOOD RADIATIONAL COOLING SETUP FOR THE REGION WITH POTENTIAL
FOR FROST ACCRUAL OVER MUCH OF THE FORECAST AREA AS TEMPS FALL INTO
THE 30S. WITH THE GROWING SEASON HAVING ADVANCED ENOUGH ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...POTENTIAL FOR FROST HEADLINES
EARLY WEDNESDAY. WILL CONTINUE TO HIGHLIGHT IN THE HWO AT THIS TIME.
REMAINDER OF THE SHORT TERM WILL BE DRY WITH WARM ADVECTION
COMMENCING BY LATE WEDNESDAY AS RIDGING ALOFT EXPANDS EAST INTO THE
OHIO VALLEY. A WARM FRONT WILL LIFT ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND MAY BRING A BRIEF INCREASE IN CLOUDS. ANY PRECIP
ASSOCIATED WITH THE WARM FRONT HOWEVER SHOULD REMAIN TO THE
NORTHWEST OF THE REGION.

TEMPS...MAVMOS GUIDANCE SUPPORTED LOW LEVEL THERMALS FOR HIGHS BOTH
TUESDAY AND WEDNESDAY...WITH TEMPS SLIPPING BACK INTO THE 60S BOTH
DAYS OVER MUCH OF THE FORECAST AREA. AS MENTIONED ABOVE...TUESDAY
NIGHT LOOKING FROSTY AS TEMPS EXPECTED TO FALL INTO THE 30S. WENT
NEAR MOS GUIDANCE FOR LOWS ALL THREE NIGHTS.

&&

.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 300 PM EDT MON APR 21 2014

THE LONG TERM PERIOD WILL START OUT WET AND END WET. HOWEVER THERE
ARE A LOT OF DIFFERENCES BETWEEN MODELS ON HOW QUICKLY THE RAIN
RETURNS LATE IN THE LONG TERM.

A COLD FRONT WILL MOVE RAPIDLY EAST ACROSS OUR REGION THURSDAY NIGHT
PRODUCING NUMEROUS SHOWERS AND A FEW THUNDERSTORMS THURSDAY
EVENING.  THESE WILL GRADUALLY END OVER NIGHT AS THE COLD FRONT
MOVES RAPIDLY EAST.

FRIDAY THROUGH SATURDAY WILL BE MOSTLY DRY.  WILL MENTION A SLIGHT
CHANCE OF SHOWERS IN OUR FAR NORTH SATURDAY AS SEVERAL MODELS
INDICATE NEAR TRACE QPF AMOUNTS THERE AND IT IS ALSO CLOSER TO THE
SURFACE LOW OVER THE GREAT LAKES.

MODELS MOVE STRONG HIGH PRESSURE INTO SOUTHERN CANADA NORTH OF THE
GREAT LAKES.  THEY ALSO DEVELOP A WARM FRONT OVER THE LOWER
MISSISSIPPI VALLEY AS LOW PRESSURE MOVES INTO THE CENTRAL PLAINS
SUNDAY.  THE EURO IS AGGRESSIVE IN SPREADING RAIN INTO OUR REGION AS
EARLY AS SATURDAY NIGHT...WHILE THE GFS ALL BUT FAR SOUTHWEST
SECTIONS DRY THROUGH THE PERIOD.  THE GEMNH MODEL IS NOT AS SLOW AS
THE GFS...BUT SOMEWHAT IN BETWEEN MODELS.  WILL LEAN IN THAT
DIRECTION AS THIS SEEMS A GOOD COMPROMISE.

MADE A FEW TWEAKS IN TEMPERATURES...BUT OVERALL ALL BLEND
TEMPERATURES SEEEM OK MOST PERIODS.

&&

.AVIATION /DISCUSSION FOR THE 21/18Z TAF ISSUANCE/...
ISSUED AT 100 PM EDT MON APR 21 2014

MOSTLY VFR. HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY.

LOW PRESSURE OVER NORTHERN LAKE MICHIGAN AND A TRAILING COLD FRONT
ACROSS EASTERN IOWA WILL MOVE SOUTHEAST ACROSS OUR REGION DURING THE
MIDDLE AND LATER PARTS OF TONIGHT.  VFR CONDITIONS WILL CONTINUE
THIS AFTERNOON. HOWEVER SCATTERED SHOWERS AND AN ISOLATED
THUNDERSHOWER WILL INCREASE ACROSS OUR REGION LATE THIS AFTERNOON
AND EARLY TONIGHT. WILL GO WITH PREVAILING SHOWERS AND VCTS
BEGINNING AT MOST SITES AROUND 00Z-02Z TIME PERIOD. MODELS INDICATE
MVFR CEILINGS MAY OCCUR ALONG AND JUST BEHIND FRONT AS SHOWERS
INCREASE ALONG THE COLD FRONT OVERNIGHT.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. WINDS THIS AFTERNOON
WILL BE SOUTHWEST 10 TO 12 KNOTS DECREASING A LITTLE THIS EVENING
AND THEN BECOMING NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS
TO 25 KNOTS TUESDAY MORNING.

&&

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

&&

$$

SYNOPSIS...RYAN
NEAR TERM...RYAN/CP
SHORT TERM...RYAN
LONG TERM...JH
AVIATION...JH

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

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







000
FXUS63 KIWX 211702
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
102 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 1215 PM EDT MON APR 21 2014

TEMPERATURES WILL CLIMB INTO THE MID TO UPPER 70S THIS AFTERNOON
AHEAD OF A COLD FRONT THAT WILL MOVE ACROSS THE AREA OVERNIGHT.
SHOWERS AND ISOLATED THUNDERSTORMS WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO THE OVERNIGHT HOURS. COOLER AND DRIER
WEATHER IS EXPECTED FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN...WITH HIGHS IN THE 50S.

&&

.UPDATE...
ISSUED AT 1254 PM EDT MON APR 21 2014

MINOR CHANGES ON EARLIER AFTN UPDATE TO PUSH BACK TIMING OF POPS
NW TODAY AND TO LOWER POPS SE. BASED ON CURRENT RADAR TRENDS AND
LATEST MODEL RUNS MOVEMENT OF SHOWERS INTO THE AREA APPEARS A BIT
SLOWER THAN EARLIER FCST REQUIRING THESE ADJUSTMENTS. NO OTHER
SGFNT CHANGES ATTM.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM EDT MON APR 21 2014

PAIR OF PV ANOMALIES CURRENTLY TRAVERSING SOUTHERN CANADA...ONE
WITH A WELL DEFINED "SWIRL" ON MORNING WATER VAPOR...WILL BE THE
MAIN ITEMS TO NOTE FOR TODAY`S SHORT TERM FORECAST. THERE ALSO
EXISTS A LOOSELY ORGANIZED MIDLEVEL TROUGH OVER THE SOUTHERN
PLAINS...MUDDLED BY CONVECTIVE ELEMENTS...THAT MAY AID PRECIP
CHANCES SOMEWHAT LATER TODAY AS IT SHEARS NORTHEAST. NORTHERN
STREAM WAVE WILL BE THE MAIN FEATURE TO WATCH THOUGH AS A
STRENGTHENING MID/UPPER LEVEL JET STREAK IS EXPECTED TO CARVE OUT
A DECENT TROUGH OVER THE GREAT LAKES BY LATE TONIGHT DUE TO
AMPLIFYING PATTERN ALOFT OVER MUCH OF THE CONUS. THIS WILL SUPPORT
CYCLOGENESIS OVER THE CENTRAL GREAT LAKES WITH A CORRESPONDING
COLD FRONTAL PASSAGE FOR OUR CWA AROUND MIDNIGHT TONIGHT. BEST
UPPER JET DYNAMICS PASS JUST TO OUR NORTH BUT DECENT MIDLEVEL
HEIGHT FALLS AND CORRESPONDING LOW LEVEL CONVERGENCE SHOULD BE
ABLE TO SUPPORT AT LEAST SCATTERED SHOWERS OVERNIGHT GIVEN
ADEQUATE MOISTURE/INSTABILITY. SOUTHWEST FLOW/THETA-E ADVECTION
FINALLY BEGINS TO INCREASE THIS AFTERNOON AND FORECAST
SOUNDINGS/RH FIELDS SHOW A HEALTHY REGION OF DEEP LAYER MOISTURE
CONVERGENCE RIGHT AHEAD OF THE FRONT. SURFACE BASED INSTABILITY
DOES INCREASE BUT WILL BE VERY LIMITED WITH ONLY A FEW HUNDRED
J/KG GIVEN LARGELY MOIST ADIABATIC LAPSE RATES. THIS WILL LIKELY
AID THE RESPONSE TO OVERALL MODEST SYNOPTIC FORCING BUT COULD ALSO
SUPPORT AN ISOLATED THUNDERSTORM DURING THE EVENING HOURS. DOUBT
PRECIP COVERAGE WILL BE WIDESPREAD ENOUGH TO WARRANT CATEGORICAL
POPS THOUGH AND WILL STICK WITH LIKELY WORDING. ALSO EXPECT PRECIP
TO HOLD OFF FOR MUCH OF THE DAY GIVEN LATE ARRIVAL OF CONVERGENT
BOUNDARY AND SUFFICIENT LOW LEVEL MOISTURE...AN IDEA SUPPORTED BY
LATEST HI-RES GUIDANCE. THIS SHOULD ALLOW FOR ANOTHER DAY AT LEAST
IN THE MID 70S...IF NOT UPPER 70S...GIVEN INCREASING WAA AND MUCH
DEEPER PBL MIXING. NOTE THIS WILL BE IN SPITE OF INCREASING CLOUD
COVER. EXPECT A SHARP GRADIENT IN OVERNIGHT LOWS DEPENDING ON
EXACT TIMING OF COLD FRONT. AIRMASS IMMEDIATELY BEHIND THE FRONT
IS NOT PARTICULARLY COLD BUT STEADY CAA AND NORTHWEST FLOW OFF
LAKE MICHIGAN COULD ALLOW OUR NORTHWEST ZONES TO DROP INTO THE
UPPER 30S/LOWER 40S AROUND 12Z TUESDAY.

&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EDT MON APR 21 2014

TUESDAY WILL BEGIN THE PERIOD WITH COLD AIR ADVECTION AND A RETURN
TO BELOW NORMAL TEMPERATURES. COLD FRONT WILL BE EAST OF THE AREA
WITH NORTHWEST WINDS IN ITS WAKE. LAKE SHADOW SHOULD SPREAD WELL
INLAND AND KEEP TEMPS ACROSS NW IN AND SW MI IN THE UPPER 40S TO
LOWER 50S AT BEST. REMAINDER OF THE AREA LIKELY TO REBOUND INTO MID
AND UPPER 50S WITH AFTERNOON INSOLATION BUT BREEZY CONDITIONS WILL
MAKE IT FEEL EVEN COOLER. HIGH PRESSURE WILL NOSE IN TUE NIGHT AND
STILL EXPECT A GOOD RADIATIONAL COOLING NIGHT WITH LOWS NEAR OR JUST
BELOW FREEZING AND WIDESPREAD FROST LIKELY.

HIGH SLIDES EAST ON WEDNESDAY WITH RETURN FLOW DEVELOPING WED AFTN
AND NIGHT. MODELS DEVELOPING SOME LIGHT QPF IN WARM AIR ADVECTION AS
LOW LEVEL JET INCREASES WED NIGHT. SOUNDING PROFILES ARE VERY DRY IN
THE LOWER LEVELS AND IT WILL ONCE AGAIN BE DIFFICULT TO SATURATE
LOWER LEVELS. LIKELY SEE VIRGA EVENT WITH SOME POSSIBLE SPRINKLES
OVER THE NW. NOT READY TO INCLUDE THE VERY LOW POPS GIVEN BY
ALLBLEND LOOKING AT THE SIGNIFICANT DEW POINT DEPRESSIONS.

BETTER CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS ARRIVE LATE
THURSDAY AFTERNOON IN WEST AND IN THE EVENING MOST AREAS. MODEL
TIMING DIFFERENT BY A FEW HOURS BUT STILL WORTHY OF LIKELY POPS WITH
GOOD FORCING ALONG OCCLUDED FRONT LIFTING THROUGH THE AREA.

SIGNIFICANT MODEL DIFFERENCES CONTINUE IN WAKE OF THIS BOUNDARY FOR
FRIDAY AND THE UPCOMING WEEKEND WITH SECONDARY COLD FRONT. GFS
CONTINUES TO SHOW MUCH COLDER AIR WRAPPING AROUND A STRONG LOW IN
THE WESTERN LAKES WHILE ECMWF IS NOT AS COLD AND FURTHER NORTH. 00Z
GFS IS VERY COLD AT 850MB FOR THIS WEEKEND WITH TEMPS AROUND -7C TO
-9C SATURDAY OVER OUR AREA WHILE ECMWF IS IN THE +2C TO +7C RANGE.
GIVEN THE DIFFERENCES AND UNCERTAINTY HAVE OPTED FOR THE ALLBLEND
WHICH IS STILL QUITE COOL AND SIMILAR TO MEAN MODEL ENSEMBLES.
FURTHER ADJUSTMENTS WILL OBVIOUSLY BE NECESSARY AS DETERMINISTIC
MODEL SOLUTIONS CONVERGE.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1254 PM EDT MON APR 21 2014

AREA SHRA AND ISOLATED TS ASSOCIATED WITH SHRTWV/CDFNT MOVG INTO
THE UPR GRTLKS REGION AND SRN STREAM CIRCULATION EJECTING NE FROM
THE SRN PLAINS WAS MOVG ACROSS SE WI/WRN IL EARLY THIS AFTN AND
SHOULD MOVE ACROSS NRN INDIANA LATE THIS AFTN AND TONIGHT. LOW
LEVELS REMAIN RATHER DRY SO GENERALLY VFR EXPECTED AHEAD OF THE
CDFNT WITH A SHORT PERIOD OF MVFR CIGS IN CAA REGIME BEHIND THE
FRONT BEFORE SKIES CLEAR EARLY TUE. NW WINDS GUSTING TO AROUND
25KT EXPECTED BEHIND THE FRONT LATE TONIGHT AND TUE MORNING.

&&

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

$$

UPDATE...JT
SYNOPSIS...CEO
SHORT TERM...AGD
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
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000
FXUS63 KIND 211700
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
100 PM EDT MON APR 21 2014

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

&&

.SYNOPSIS...
ISSUED AT 304 AM EDT MON APR 21 2014

SHOWERS WITH EMBEDDED THUNDERSTORMS WILL DEVELOP LATER TODAY AND
CONTINUE TONIGHT AS A COLD FRONT MOVES THROUGH THE OHIO VALLEY.
COOLER DRIER WEATHER RETURNS FOR TUESDAY AND WEDNESDAY AS HIGH
PRESSURE MOVES THROUGH THE REGION. WARMER AND MORE UNSETTLED WEATHER
RETURNS FOR LATE WEEK WITH THE PASSAGE OF ANOTHER COLD FRONT. BEHIND
THE FRONT...COOLER WEATHER WILL RETURN FOR THE WEEKEND.

&&

.NEAR TERM /TODAY/...
ISSUED AT 945 AM EDT MON APR 21 2014

RADAR MOSAIC SHOWS SOME ECHOES OF 20-30 DBZ MOVING INTO KNOX COUNTY
AT 930 AM AND VISIBLE SATELLITE SHOWS A CONVECTIVE NATURE TO THE
CLOUDS ASSOCIATED WITH THESE ECHOES. THUS FAR NO PRECIPITATION HAS
BEEN REPORTED AT THE GROUND UNDER THESE CLOUDS AND WITH DEW POINTS
IN THE MID 40S TO LOW 50S AND A FAIRLY DRY COLUMN THINK CONTINUING
WITH NO MEASURABLE PRECIP TIL AFTER 19Z IS A GOOD IDEA. HOWEVER
CAN/T RULE OUT A FEW SPRINKLES DEVELOPING IN THE SOUTHWEST...SO WILL
GO AHEAD AND ADD A CHANCE FOR SPRINKLES THERE FOR THE NEXT FEW
HOURS. REST OF THE FORECAST IS IN GOOD SHAPE WITH HIGHS IN THE MID
TO UPPER 70S STILL ON TRACK AND HI RES MODELS SHOWING SIMILAR TIMING
TO MEASURABLE PRECIP AS THE GOING FORECAST...AFTER 19Z WITH BEST
CHANCES NOT ARRIVING UNTIL SOMETIME AFTER 0Z.

PREVIOUS DISCUSSION FOLLOWS...

MAIN FOCUS FOR TODAY IS THE APPROACH OF THE UPPER WAVE AND COLD
FRONT TO THE WEST AS LOW PRESSURE OFF THE NORTH CAROLINA COAST
FINALLY SHIFTS FURTHER EAST INTO THE ATLANTIC OCEAN. THIS WILL
ENABLE THE RIDGE AXIS TO LIKEWISE SHIFT EAST TO THE U S EAST COAST
BY LATE DAY. CLOUD COVERAGE WILL INCREASE THROUGHOUT THE DAY AS
MOISTURE ADVECTS INTO THE REGION FROM THE SOUTHWEST. WEAK LIFT AND
FORCING WILL MOVE INTO THE OHIO VALLEY DURING THE COURSE OF THE
AFTERNOON WITH SCATTERED SHOWERS AND PERHAPS A THUNDERSTORM
SPREADING EAST INTO THE FORECAST AREA BY LATE AFTERNOON. MORE
EXPANSIVE COVERAGE TO RAINFALL WILL LIKELY HOLD OFF UNTIL THIS
EVENING AS MODEL SOUNDINGS INDICATING IT WILL TAKE MUCH OF THE DAY
TO MOISTEN THE BOUNDARY LAYER. WILL CARRY MAINLY LOW CHANCE POPS FOR
MID/LATE AFTERNOON.

TEMPS...FILTERED SUN THROUGH THE MORNING AND WARM ADVECTION AHEAD OF
THE FRONT WILL ENABLE ANOTHER WARM DAY PEAKING IN THE 70S. LOW LEVEL
THERMALS SUPPORTED MAX TEMPS AT OR JUST ABOVE MAVMOS IN THE
MID/UPPER 70S.

&&

.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 304 AM EDT MON APR 21 2014

FORECAST CHALLENGES FOCUS ON PRECIP CHANCES TONIGHT AS THE FRONT
SWINGS THROUGH THE REGION...AND POTENTIAL FOR FROSTY TEMPS WEDNESDAY
MORNING.

WEAKENING UPPER WAVE WILL TRACK THROUGH THE OHIO VALLEY WITH THE
COLD FRONT TONIGHT WITH RAIN SHOWERS AND EMBEDDED THUNDERSTORMS.
MOST WIDESPREAD COVERAGE EXPECTED DURING THE EVENING AND EARLY
OVERNIGHT...WITH PRECIP GRADUALLY SHIFTING INTO THE SOUTHERN/EASTERN
PORTIONS OF THE FORECAST AREA AFTER 06Z TUESDAY. BRIEF PERIOD OF
ISENTROPIC LIFT AND SUBTLE LOW LEVEL CONVERGENCE WITHIN A NARROW
RIBBON OF DEEPER MOISTURE WILL BE THE MAIN RAINFALL CATALYSTS
TONIGHT AND WILL MAINTAIN LIKELY POPS. RAINFALL AMOUNTS WILL BE
GENERALLY LIGHT AT A QUARTER INCH OR LESS.

COLD FRONT WILL BE EAST OF THE FORECAST AREA BY DAYBREAK TUESDAY
WITH THE DEEPER MOISTURE DEPARTING ALONG WITH IT. EXPECT SKIES TO
CLEAR QUICKLY TUESDAY MORNING AS MODEL SOUNDINGS AND RH PROGS
INDICATING A RAPIDLY DRYING COLUMN. DESPITE STRONG COLD ADVECTION
AND A  SHARP WAVE ALOFT PASSING THROUGH THE LOWER GREAT LAKES DURING
THE COURSE OF THE DAY...EXPECT ANY CU FORMATION TO BE SIGNIFICANTLY
LIMITED BY THE INCREASING SUBSIDENCE AND DRY AIR ADVECTING INTO THE
REGION. EFFICIENT LOW LEVEL MIXING WILL BRING STRONGER WINDS TO THE
SURFACE TUESDAY AFTERNOON WITH MAX GUSTS UP TO 25 MPH.

HIGH PRESSURE RIDGE CENTERS ACROSS THE REGION TUESDAY NIGHT WITH
NORTHERLY WINDS BECOMING LIGHT AFTER MIDNIGHT. WITH CLEAR
SKIES...GOOD RADIATIONAL COOLING SETUP FOR THE REGION WITH POTENTIAL
FOR FROST ACCRUAL OVER MUCH OF THE FORECAST AREA AS TEMPS FALL INTO
THE 30S. WITH THE GROWING SEASON HAVING ADVANCED ENOUGH ACROSS THE
SOUTHERN HALF OF THE FORECAST AREA...POTENTIAL FOR FROST HEADLINES
EARLY WEDNESDAY. WILL CONTINUE TO HIGHLIGHT IN THE HWO AT THIS TIME.
REMAINDER OF THE SHORT TERM WILL BE DRY WITH WARM ADVECTION
COMMENCING BY LATE WEDNESDAY AS RIDGING ALOFT EXPANDS EAST INTO THE
OHIO VALLEY. A WARM FRONT WILL LIFT ACROSS THE FORECAST AREA
WEDNESDAY NIGHT AND MAY BRING A BRIEF INCREASE IN CLOUDS. ANY PRECIP
ASSOCIATED WITH THE WARM FRONT HOWEVER SHOULD REMAIN TO THE
NORTHWEST OF THE REGION.

TEMPS...MAVMOS GUIDANCE SUPPORTED LOW LEVEL THERMALS FOR HIGHS BOTH
TUESDAY AND WEDNESDAY...WITH TEMPS SLIPPING BACK INTO THE 60S BOTH
DAYS OVER MUCH OF THE FORECAST AREA. AS MENTIONED ABOVE...TUESDAY
NIGHT LOOKING FROSTY AS TEMPS EXPECTED TO FALL INTO THE 30S. WENT
NEAR MOS GUIDANCE FOR LOWS ALL THREE NIGHTS.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
ISSUED AT 231 AM EDT MON APR 21 2014

LONG TERM PERIOD WILL START WITH A FRONTAL SYSTEM APPROACHING THE
AREA. MODEL CONSISTENCY STILL LEAVES A BIT TO BE DESIRED...BUT MODEL
INSTABILITY PROGS...ALONG WITH CONVECTIVE PRECIP PROGS...DEEP LAYER
SHEAR AND TIMING OF FRONTAL PASSAGE...SUGGEST ORGANIZED CONVECTION
MAY BE A GOOD BET LATE THURSDAY AFTERNOON INTO THE OVERNIGHT. WILL
HAVE TO MONITOR THIS POTENTIAL AS THE WEEK WEARS ON.

WILL REMOVE ALLBLEND POPS FRIDAY AS FRONTAL BOUNDARY WILL BE WELL
EAST OF THE AREA AND HIGH PRESSURE BUILDING INTO THE AREA REGARDLESS
OF MODEL CHOICE. GUIDANCE BRINGS ANOTHER SYSTEM INTO THE AREA VERY
LATE IN THE PERIOD...BUT WILL TEMPER THESE POPS A BIT AS MODEL
INCONSISTENCIES ARE HIGH.

MAX TEMPERATURES NEEDED BUMPED UP A BIT MOST PERIODS AS 850 TEMPS
AND LOW LEVEL THICKNESSES SUGGESTED ALLBLEND TOO COOL.

&&

.AVIATION /DISCUSSION FOR THE 21/18Z TAF ISSUANCE/...
ISSUED AT 100 PM EDT MON APR 21 2014

MOSTLY VFR. HOWEVER A PERIOD OF MVFR CEILINGS POSSIBLE AFTER
MIDNIGHT TONIGHT TO NEAR SUNRISE TUESDAY. MODERATE TO BRISK WINDS
WILL OCCUR TUESDAY.

LOW PRESSURE OVER NORTHERN LAKE MICHIGAN AND A TRAILING COLD FRONT
ACROSS EASTERN IOWA WILL MOVE SOUTHEAST ACROSS OUR REGION DURING THE
MIDDLE AND LATER PARTS OF TONIGHT.  VFR CONDITIONS WILL CONTINUE
THIS AFTERNOON. HOWEVER SCATTERED SHOWERS AND AN ISOLATED
THUNDERSHOWER WILL INCREASE ACROSS OUR REGION LATE THIS AFTERNOON
AND EARLY TONIGHT. WILL GO WITH PREVAILING SHOWERS AND VCTS
BEGINNING AT MOST SITES AROUND 00Z-02Z TIME PERIOD. MODELS INDICATE
MVFR CEILINGS MAY OCCUR ALONG AND JUST BEHIND FRONT AS SHOWERS
INCREASE ALONG THE COLD FRONT OVERNIGHT.

FOLLOWING THE COLD FRONT MUCH DRIER AIR SPREAD IN FROM THE NORTHWEST
CAUSING RAPID CLEARING BY MID OR LATE MORNING. WINDS THIS AFTERNOON
WILL BE SOUTHWEST 10 TO 12 KNOTS DECREASING A LITTLE THIS EVENING
AND THEN BECOMING NORTHWEST AND INCREASING UP TO 15 KNOTS AND GUSTS
TO 25 KNOTS TUESDAY MORNING.

&&

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

&&

$$

SYNOPSIS...RYAN
NEAR TERM...RYAN/CP
SHORT TERM...RYAN
LONG TERM...NIELD
AVIATION...JH

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

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












000
FXUS63 KIWX 211615
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
1215 PM EDT MON APR 21 2014

.SYNOPSIS...
ISSUED AT 1215 PM EDT MON APR 21 2014

TEMPERATURES WILL CLIMB INTO THE MID TO UPPER 70S THIS AFTERNOON
AHEAD OF A COLD FRONT THAT WILL MOVE ACROSS THE AREA OVERNIGHT.
SHOWERS AND ISOLATED THUNDERSTORMS WILL ARRIVE LATE THIS
AFTERNOON AND CONTINUE INTO THE OVERNIGHT HOURS. COOLER AND DRIER
WEATHER IS EXPECTED FOR TUESDAY AND WEDNESDAY AS HIGH PRESSURE
SETTLES IN...WITH HIGHS IN THE 50S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM EDT MON APR 21 2014

PAIR OF PV ANOMALIES CURRENTLY TRAVERSING SOUTHERN CANADA...ONE
WITH A WELL DEFINED "SWIRL" ON MORNING WATER VAPOR...WILL BE THE
MAIN ITEMS TO NOTE FOR TODAY`S SHORT TERM FORECAST. THERE ALSO
EXISTS A LOOSELY ORGANIZED MIDLEVEL TROUGH OVER THE SOUTHERN
PLAINS...MUDDLED BY CONVECTIVE ELEMENTS...THAT MAY AID PRECIP
CHANCES SOMEWHAT LATER TODAY AS IT SHEARS NORTHEAST. NORTHERN
STREAM WAVE WILL BE THE MAIN FEATURE TO WATCH THOUGH AS A
STRENGTHENING MID/UPPER LEVEL JET STREAK IS EXPECTED TO CARVE OUT
A DECENT TROUGH OVER THE GREAT LAKES BY LATE TONIGHT DUE TO
AMPLIFYING PATTERN ALOFT OVER MUCH OF THE CONUS. THIS WILL SUPPORT
CYCLOGENESIS OVER THE CENTRAL GREAT LAKES WITH A CORRESPONDING
COLD FRONTAL PASSAGE FOR OUR CWA AROUND MIDNIGHT TONIGHT. BEST
UPPER JET DYNAMICS PASS JUST TO OUR NORTH BUT DECENT MIDLEVEL
HEIGHT FALLS AND CORRESPONDING LOW LEVEL CONVERGENCE SHOULD BE
ABLE TO SUPPORT AT LEAST SCATTERED SHOWERS OVERNIGHT GIVEN
ADEQUATE MOISTURE/INSTABILITY. SOUTHWEST FLOW/THETA-E ADVECTION
FINALLY BEGINS TO INCREASE THIS AFTERNOON AND FORECAST
SOUNDINGS/RH FIELDS SHOW A HEALTHY REGION OF DEEP LAYER MOISTURE
CONVERGENCE RIGHT AHEAD OF THE FRONT. SURFACE BASED INSTABILITY
DOES INCREASE BUT WILL BE VERY LIMITED WITH ONLY A FEW HUNDRED
J/KG GIVEN LARGELY MOIST ADIABATIC LAPSE RATES. THIS WILL LIKELY
AID THE RESPONSE TO OVERALL MODEST SYNOPTIC FORCING BUT COULD ALSO
SUPPORT AN ISOLATED THUNDERSTORM DURING THE EVENING HOURS. DOUBT
PRECIP COVERAGE WILL BE WIDESPREAD ENOUGH TO WARRANT CATEGORICAL
POPS THOUGH AND WILL STICK WITH LIKELY WORDING. ALSO EXPECT PRECIP
TO HOLD OFF FOR MUCH OF THE DAY GIVEN LATE ARRIVAL OF CONVERGENT
BOUNDARY AND SUFFICIENT LOW LEVEL MOISTURE...AN IDEA SUPPORTED BY
LATEST HI-RES GUIDANCE. THIS SHOULD ALLOW FOR ANOTHER DAY AT LEAST
IN THE MID 70S...IF NOT UPPER 70S...GIVEN INCREASING WAA AND MUCH
DEEPER PBL MIXING. NOTE THIS WILL BE IN SPITE OF INCREASING CLOUD
COVER. EXPECT A SHARP GRADIENT IN OVERNIGHT LOWS DEPENDING ON
EXACT TIMING OF COLD FRONT. AIRMASS IMMEDIATELY BEHIND THE FRONT
IS NOT PARTICULARLY COLD BUT STEADY CAA AND NORTHWEST FLOW OFF
LAKE MICHIGAN COULD ALLOW OUR NORTHWEST ZONES TO DROP INTO THE
UPPER 30S/LOWER 40S AROUND 12Z TUESDAY.

&&

.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 345 AM EDT MON APR 21 2014

TUESDAY WILL BEGIN THE PERIOD WITH COLD AIR ADVECTION AND A RETURN
TO BELOW NORMAL TEMPERATURES. COLD FRONT WILL BE EAST OF THE AREA
WITH NORTHWEST WINDS IN ITS WAKE. LAKE SHADOW SHOULD SPREAD WELL
INLAND AND KEEP TEMPS ACROSS NW IN AND SW MI IN THE UPPER 40S TO
LOWER 50S AT BEST. REMAINDER OF THE AREA LIKELY TO REBOUND INTO MID
AND UPPER 50S WITH AFTERNOON INSOLATION BUT BREEZY CONDITIONS WILL
MAKE IT FEEL EVEN COOLER. HIGH PRESSURE WILL NOSE IN TUE NIGHT AND
STILL EXPECT A GOOD RADIATIONAL COOLING NIGHT WITH LOWS NEAR OR JUST
BELOW FREEZING AND WIDESPREAD FROST LIKELY.

HIGH SLIDES EAST ON WEDNESDAY WITH RETURN FLOW DEVELOPING WED AFTN
AND NIGHT. MODELS DEVELOPING SOME LIGHT QPF IN WARM AIR ADVECTION AS
LOW LEVEL JET INCREASES WED NIGHT. SOUNDING PROFILES ARE VERY DRY IN
THE LOWER LEVELS AND IT WILL ONCE AGAIN BE DIFFICULT TO SATURATE
LOWER LEVELS. LIKELY SEE VIRGA EVENT WITH SOME POSSIBLE SPRINKLES
OVER THE NW. NOT READY TO INCLUDE THE VERY LOW POPS GIVEN BY
ALLBLEND LOOKING AT THE SIGNIFICANT DEW POINT DEPRESSIONS.

BETTER CHANCE FOR SHOWERS AND A FEW THUNDERSTORMS ARRIVE LATE
THURSDAY AFTERNOON IN WEST AND IN THE EVENING MOST AREAS. MODEL
TIMING DIFFERENT BY A FEW HOURS BUT STILL WORTHY OF LIKELY POPS WITH
GOOD FORCING ALONG OCCLUDED FRONT LIFTING THROUGH THE AREA.

SIGNIFICANT MODEL DIFFERENCES CONTINUE IN WAKE OF THIS BOUNDARY FOR
FRIDAY AND THE UPCOMING WEEKEND WITH SECONDARY COLD FRONT. GFS
CONTINUES TO SHOW MUCH COLDER AIR WRAPPING AROUND A STRONG LOW IN
THE WESTERN LAKES WHILE ECMWF IS NOT AS COLD AND FURTHER NORTH. 00Z
GFS IS VERY COLD AT 850MB FOR THIS WEEKEND WITH TEMPS AROUND -7C TO
-9C SATURDAY OVER OUR AREA WHILE ECMWF IS IN THE +2C TO +7C RANGE.
GIVEN THE DIFFERENCES AND UNCERTAINTY HAVE OPTED FOR THE ALLBLEND
WHICH IS STILL QUITE COOL AND SIMILAR TO MEAN MODEL ENSEMBLES.
FURTHER ADJUSTMENTS WILL OBVIOUSLY BE NECESSARY AS DETERMINISTIC
MODEL SOLUTIONS CONVERGE.

&&

.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 555 AM EDT MON APR 21 2014

VFR CONDITIONS WILL PERSIST THROUGH THE AFTERNOON. SHORTWAVE
TROUGH WILL THEN DIG OVER THE GREAT LAKES TONIGHT AND SEND A COLD
FRONT THROUGH THE REGION. LOW LEVEL CONVERGENCE IN A MOIST AND WEAKLY
UNSTABLE ENVIRONMENT WILL LEAD TO NUMEROUS SHOWERS AND PERHAPS AN
ISOLATED THUNDERSTORM LATE THIS EVENING. LATEST HI-RES GUIDANCE
STILL SUGGESTS PRECIP HOLDING OFF UNTIL AROUND 00Z FOR KSBN AND
03Z FOR KFWA. BRIEF REDUCTIONS TO MVFR CATEGORY ARE POSSIBLE BUT
IMPROVEMENT EXPECTED BY TUESDAY MORNING AS HIGH PRESSURE AND DRY
AIR PUSH BACK INTO THE REGION.


&&

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

$$

SYNOPSIS...CEO
SHORT TERM...AGD
LONG TERM...LASHLEY
AVIATION...AGD


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