Area Forecast Discussion
Issued by NWS Indianapolis, IN

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000
FXUS63 KIND 290435
AFDIND

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
1233 AM EDT FRI MAY 29 2015

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

&&

.SYNOPSIS...
ISSUED AT 218 PM EDT THU MAY 28 2015

HIGH PRESSURE ACROSS THE APPALACHIANS WILL ALLOW FOR DRY WEATHER
TONIGHT. HOWEVER...THUNDERSTORM CHANCES WILL RETURN FOR THE WEEKEND
WITH THE BEST CHANCES ON SATURDAY AS A COLD FRONT DROPS SOUTHEAST
ACROSS CENTRAL INDIANA.

THE WARM WEATHER WILL CONTINUE THOUGH SATURDAY BEFORE MUCH COOLER
AIR ARRIVES ON SUNDAY. THEN...TEMPERATURES WILL MODERATE NEXT WEEK
AS SOUTHERLY FLOW RETURNS. THIS SHOULD ALLOW TEMPERATURES TO RETURN
TO THE 80S BY WEDNESDAY AFTER HIGHS SUNDAY ONLY IN THE 60S.
MEANWHILE...THERE SMALL THUNDERSTORM CHANCES AT TIMES NEXT WEEK AS
THE FRONTAL SYSTEM LIFTS BACK TO THE NORTH IN THE SOUTHERLY FLOW AND
AHEAD OF A SLOW MOVING UPPER LOW OVER THE LOWER MISSISSIPPI
VALLEY.

&&

.NEAR TERM /OVERNIGHT/...
ISSUED AT 949 PM EDT THU MAY 28 2015

CU HAS LARGELY DIMINISHED WITH SUNSET...LEAVING CIRRUS TO DRIFT
INTO THE REGION FROM THE SOUTHWEST. AREA OF MORE EXTENSIVE CLOUD
COVER DRIFTING NORTH THROUGH EASTERN TENNESSEE AND KENTUCKY. 0130Z
TEMPS WERE IN THE 70S.

LITTLE CHANGE NEEDED FOR THE EVENING UPDATE. AREA OF SUBSIDENCE
NOTED ON WV SATELLITE SLOWLY LIFTING OUT TO THE NORTHEAST AS DEEPER
MOISTURE SPREADS INTO THE REGION FROM THE SOUTHWEST AND FROM AN
UPPER WAVE OVER THE TENNESSEE VALLEY. DEWPOINTS BEGINNING TO CREEP
BACK UP INTO THE LOWER 60S AND SHOULD CONTINUE TO DO SO THROUGH THE
NIGHT. CIRRUS WILL CONTINUE TO MOVE ACROSS CENTRAL INDIANA
OVERNIGHT...AND SOUTHEAST COUNTIES MAY BE GRAZED BY CLOUDS
ASSOCIATED WITH THE NORTHWARD MOVING UPPER WAVE. HI-RES GUIDANCE
GENERATING SOME CONVECTION WITH THIS FEATURE LATE AS IT LIFTS
THROUGH EASTERN KENTUCKY INTO WESTERN OHIO...BUT THIS ACTIVITY
SHOULD REMAIN EAST OF THE FORECAST AREA.

COULD SEE LOCALIZED FOG DEVELOP ONCE AGAIN LATE TONIGHT WITH
GENERALLY LIGHT FLOW. LOW TEMPS IN THE LOWER AND MIDDLE 60S STILL
LOOK REASONABLE.

ZONE AND GRID UPDATES OUT.

&&

.SHORT TERM /FRIDAY THROUGH SUNDAY/...

ISSUED AT 218 PM EDT THU MAY 28 2015

UNSETTLED WEATHER IS EXPECTED THIS WEEKEND WITH MUCH COOLER
TEMPERATURES BY SUNDAY.

MODELS IN PRETTY GOOD AGREEMENT AS THEY BRING A COLD FRONT SOUTHEAST
ACROSS CENTRAL INDIANA ON SATURDAY AFTERNOON AND EVENING. THEY ALSO
BRING A SERIES OF UPPER WAVES NORTHEAST OVER THE AREA AHEAD OF A
PLAINS TROUGH. WARM AND UNSTABLE AIR WILL BE IN PLACE FOR THESE
SYNOPTIC FORCING FEATURES TO INTERACT WITH ALONG WITH PRECIPITABLE
WATER AMOUNTS TO 1.7 INCHES OR SO. THE RESULT WILL BE NUMEROUS
CONVECTIVE ACTIVITY STARTING ON FRIDAY WITH THE BEST CHANCES AND
MOST QPF SATURDAY INTO SATURDAY NIGHT...WHEN 12Z MOS LIKELY TO CAT
POPS LOOK GOOD.

IN THE WAKE OF THE FRONT ON SUNDAY...MODELS MOVE THE PLAINS UPPER
TROUGH TO THE MIDDLE AND LOWER MISSISSIPPI VALLEY. THIS IS EXPECTED
TO SLOW THE COLD FRONT AND PERHAPS BRING IT SLIGHTLY FURTHER NORTH
AGAIN. THE 12Z GEM SEEMS TO BE AN OUTLIER WITH IT FURTHER SOUTH
LOCATION OF THE FRONT AND ASSOCIATED DEEP MOISTURE. THE OTHERS
INCLUDING THE 00Z ECMWF...12Z GFS AND 12Z NAM ALL TAKE A MORE
NORTHERN APPROACH WITH QPF OVER CENTRAL INDIANA ON SUNDAY...WITH THE
HIGHEST AMOUNTS ACROSS OUR SOUTHERN HALF. THIS MATCHES UP NICELY
WITH THE PREVIOUS FORECAST WITH GOOD CHANCE POPS SOUTH TAPERING OFF
TO SLIGHT CHANCE NORTHWEST.

WITH MIXED LAYER CAPES OVER 1000 J/KG FRIDAY AFTERNOON AND SATURDAY
AFTERNOON...WOULD NOT RULE OUT AN ISOLATED SEVERE STORM PER THE SPC
MARGINAL DAY2 RISK. HOWEVER...WEAK SHEAR SHOULD PREVENT ANY SORT OF
WIDESPREAD SEVERE EVENT EITHER DAY. BEST CHANCES SHOULD BE ACROSS
OUR NORTHWESTERN COUNTIES...CLOSER TO SLIGHTLY HIGHER MID AND UPPER
LEVEL WINDS. ALSO...CONFIDENCE IN THUNDERSTORMS IS LOW ON SUNDAY
EXCEPT SOUTH PER INSTABILITY PROGS. THUS...WILL GO NO HIGHER THAN
ISOLATED REGARDING THUNDERSTORMS THEN.

12Z MOS TEMPERATURES ARE PRETTY CLOSE AND APPEAR REASONABLE WITH
HIGHS IN THE LOWER TO MID 80S FRIDAY AND UPPER 70S TO LOWER 80S ON
SATURDAY. IF ANYTHING...MAY CUT A DEGREE OR TWO OFF WITH PLENTY OF
CLOUDS AND STORMS AROUND. BY SUNDAY...WITH THE FRONT SOUTH OF THE
AREA...SHOULD SEE MUCH COOLER TEMPERATURES WITH BLEND SUGGESTING
HIGHS ONLY IN THE 60S.

&&

.LONG TERM /SUNDAY THROUGH THURSDAY/...

ISSUED AT 154 PM EDT THU MAY 28 2015

THE REGIONAL MODEL INITIALIZATION WILL BE USED WITH HIGH CONFIDENCE.

THE GFS IS SAYING ABOUT WHAT IT DID YESTERDAY FOR NEXT WEEKS
FORECAST. THE LATEST EUROPEAN HAS NEARLY CONVERGED ON THIS. THE
CONVERGENCE IS PARTICULARLY EVIDENT IN THE HANDLING OF A TROUGH OVER
THE AREA THAT WILL BE VERY IMPORTANT TO OUR WEATHER.

THIS IS A STRONG INDICATION THE GFS HAS A GOOD GRIP ON WHAT WILL
HAPPEN. ADDITIONAL SUPPORTING EVIDENCE IS SMALL SPREAD BETWEEN THE
VARIOUS GFS ENSEMBLE RUNS.

&&

.AVIATION /DISCUSSION FOR 290600Z TAFS/...

ISSUED AT 1233 AM EDT FRI MAY 29 2015

EXCEPT FOR BRIEF AND LOCALIZED MVFR FOG NEAR DAYBREAK TODAY...EXPECT
VFR CONDITIONS THIS PERIOD. WINDS TO EXCEED 10 KTS BY 291600Z WITH
AFTERNOON GUSTS TODAY NEAR 20KTS.

WEAKENING UPPER TROUGH MOVING INTO INDIANA DURING DAYTIME TODAY
COMBINED WITH MAX HEATING AND HIGHER HUMIDITY SHOULD LEAD TO
SCATTERED THUNDERSTORMS AFTER 291800Z AND CONTINUING INTO 300200Z.

&&

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

$$

SYNOPSIS...MK
NEAR TERM...RYAN
SHORT TERM...MK
LONG TERM....JK
AVIATION...TUCEK

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