Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 212009
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
408 PM EDT THU MAY 21 2015

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

&&

.SYNOPSIS...
ISSUED AT 133 PM EDT THU MAY 21 2015

HIGH PRESSURE OVER THE CENTRAL PLAINS STATES IS EXPECTED TO BUILD
ACROSS CENTRAL INDIANA THROUGH THE WEEKEND. THIS WILL BRING DRY
AND WARMER WEATHER FOR FRIDAY AND SATURDAY.

A WARM FRONT WILL APPROACH THE REGION ON SATURDAY NIGHT AND
SUNDAY. THIS WILL RESULT IN SMALL CHANCES FOR RAIN LATE SATURDAY
NIGHT AND SUNDAY.

RAIN CHANCES ARE EXPECTED TO CONTINUE OVER MEMORIAL DAY AND INTO
THE NEXT WORK WEEK AS WARMER AND MORE HUMID AIR WILL BE IN PLACE
OVER CENTRAL INDIANA.

&&

.NEAR TERM /TONIGHT/...

ISSUED AT 133 PM EDT THU MAY 21 2015

SURFACE ANALYSIS EARLY THIS AFTERNOON SHOWS HIGH PRESSURE CENTERED
OVER KANSAS AND OKLAHOMA. A BROAD AREA OF LOW PRESSURE WAS FOUND
OVER EASTERN ONTARIO AND QUEBEC...EXTENDING A TROUGH ACROSS THE
GREAT LAKES. ALOFT...RIDGING REMAINED IN PLACE OVER THE CENTRAL
PLAINS AND A TROUGH WAS IN PLACE ACROSS THE ACROSS THE EASTERN 1/3
OF NORTH AMERICA. THIS WAS ALL RESULTING IN A COOLER...NW FLOW OF
AIR TO CENTRAL INDIANA.

MAIN CHALLENGE FOR TONIGHT WILL BE TEMPS.

DRY WEATHER IS EXPECTED OVERNIGHT AS THE GFS AND NAM BOTH SUGGEST
THE SURFACE HIGH PRESSURE SYSTEM BUILDING ACROSS CENTRAL INDIANA
OVERNIGHT. FORECAST SOUNDINGS AND TIME HEIGHT SECTION BOTH
INDICATE A DRY COLUMN. SUBSIDENCE ALSO INDICATED. THUS WILL TREND
TOWARD A MOSTLY CLEAR SKY. AS FOR TEMPS...MODELS SUGGEST THAT
850MB DOME OF COLD AIR LESS THAN 2C IS OVER CENTRAL INDIANA THIS
AFTERNOON...AND WILL ADVECT TO THE SOUTHEAST OVERNIGHT...ALLOWING
FOR SOME UNUSUAL WARM AIR ADVECTION FROM THE NORTHWEST. STILL WITH
MOSTLY CLEAR SKIES AND WINDS AT OR LESS THAN 5 KNTS...A GOOD NIGHT
FOR RADIATIONAL COOLING IS IN STORE. THUS WILL TREND LOWS SLIGHTLY
ABOVE PERSISTENCE.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 133 PM EDT THU MAY 21 2015

SURFACE HIGH PRESSURE APPEARS IN PLACE ACROSS CENTRAL INDIANA AND
THE OHIO VALLEY ON FRIDAY NIGHT THROUGH SATURDAY EVENING. MEANWHILE
ALOFT...THE RIDGING OVER THE CENTRAL PLAINS BEGINS TO BUILD EAST
TOWARD THE OHIO VALLEY. THIS WILL RESULT IN DRY AND PLEASANT
WEATHER THROUGH AT LEAST SATURDAY EVENING. WILL USE A BLEND ON
HIGHS AND LOWS THROUGH SATURDAY.

ON SATURDAY NIGHT AND SUNDAY. THE SURFACE HIGH WILL HAVE SHIFTED
EAST OF CENTRAL INDIANA...ALLOWING A WARMER AN MORE HUMID AIR MASS
TO ARRIVE IN CENTRAL INDIANA. MEANWHILE THE RIDGE ALOFT APPEARS TO
BECOME MORE AMPLIFIED AS IT BUILDS EAST ACROSS CENTRAL INDIANA
INTO SUNDAY. THE 300K GFS ISENTROPIC SURFACE SHOWS GOOD MID LEVEL
UPGLIDE ON SATURDAY NIGHT...AND CONTINUING INTO SUNDAY. SPECIFIC
HUMIDITIES INCREASE FROM SATURDAY NIGHT FROM NEAR 4 G/KG TO NEAR 7
K/KG BY SUNDAY AFTERNOON. FORECAST SOUNDINGS ARE A MISHMASH...WITH
THE NAM APPEAR RATHER SATURATED WITH ATTAINABLE CONVECTIVE
TEMPS...WHILE THE GFS IS LESS AGGRESSIVE AND APPEARS MORE DRY.
GIVEN THE RETURN OF MOISTURE BUT LIMITED DYNAMICS...WILL ONLY
INCLUDE SOME LOW CHANCE POPS FRO SATURDAY NIGHT AND SUNDAY FOR
NOW. WITH AN INCREASE IN CLOUDS AND POSSIBLE RAIN ON SATURDAY
NIGHT AND SUNDAY WILL TREND LOWS WARMER THAN MAVMOS AND HIGHS
COOLER THAN MEXMOS ON SUNDAY.

&&

.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 408 PM EDT THU MAY 21 2015

ENSEMBLES IN GOOD AGREEMENT IN SUGGESTING AN UPPER RIDGE OVER THE
OHIO VALLEY AT THE BEGINNING OF THE PERIOD WILL GET FLATTENED OUT
WITH TIME AS DISTURBANCES EJECT OUT OF A MEAN TROUGH OVER THE
WESTERN PARTS OF THE COUNTRY.

ENSEMBLES CONTINUE TO INDICATE DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS THROUGHOUT THE EXTENDED. PRECIPITATION POTENTIAL WILL
PROBABLY INCREASE WITH TIME NEXT WEEK AS THE UPPER RIDGE GRADUALLY
FLATTENS OUT. WILL KEEP POPS GOING ALL PERIODS FOR NOW.

&&

.AVIATION /DISCUSSION FOR THE 211800Z TAFS/...

ISSUED AT 1235 PM EDT THU MAY 21 2015

SOME LINGERING MVFR CEILINGS AROUND 020 CONTINUE IN THE KHUF/KBMG
AREAS...BUT SUSPECT THESE CEILINGS WILL SCATTER OUT SOON BASED ON
OBSERVATIONAL TRENDS AND SHORT TERM MODEL GUIDANCE.

OTHERWISE...VFR CEILINGS AROUND 035-040 EXPECTED TO SCATTER OUT FROM
NORTHWEST TO SOUTHEAST DURING THE COURSE OF THE AFTERNOON.

SURFACE WINDS 310-340 DEGREES AT 8-11 KTS WILL GRADUALLY BACK WITH
TIME AND BECOME 6 KTS OR LESS AFTER SUNSET.

&&

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

$$

SYNOPSIS...PUMA
NEAR TERM...PUMA
SHORT TERM...PUMA
LONG TERM....JAS
AVIATION...JAS

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