Area Forecast Discussion
Issued by NWS Indianapolis, IN

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FXUS63 KIND 190706 CCA
AFDIND

AREA FORECAST DISCUSSION...CORRECTED
NATIONAL WEATHER SERVICE INDIANAPOLIS IN
303 AM EDT TUE AUG 19 2014

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

&&

.SYNOPSIS...
ISSUED AT 259 AM EDT TUE AUG 19 2014

A FRONTAL SYSTEM WILL MOVE INTO THE AREA TONIGHT AND EVENTUALLY
STALL OUT. THIS WILL SERVE TO KEEP THE WEATHER UNSETTLED OVERALL
THROUGH MOST OF THE UPCOMING WEEK. A RIDGE OF HIGH PRESSURE WILL
BUILD BACK OVER THE REGION FOR THE LATTER HALF OF THE WEEKEND AND
INTO EARLY NEXT WEEK.

&&

.NEAR TERM /TODAY AND TONIGHT/...

ISSUED AT 259 AM EDT TUE AUG 19 2014

FIRST THIS MORNING...LIGHT/CALM WINDS COMBINED WITH A HUMID AIR
MASS HAS ALLOWED AREAS OF FOG TO FORM ALREADY THIS MORNING. FOR
NOW WILL CONTINUE WITH AN SPS STATEMENT MENTIONING AREAS OF FOG
WITH VISIBILITIES AROUND HALF A MILE. IN ADDITION WILL CONTINUE
TO MONITOR TO SEE IF PARTS OF CENTRAL INDIANA WILL WARRANT A DENSE
FOG ADVISORY LATER THIS MORNING.

AS FOR THE REST OF TODAY AND TONIGHT...AN UPPER TROUGH AND
ASSOCIATED FRONTAL SYSTEM WILL MOVE INTO THE AREA BY TONIGHT. BEST
LIFT AND HIGHEST PRECIPITATION THREAT WILL BE FROM MID AFTERNOON
UNTIL MIDNIGHT TONIGHT. MODELS APPEAR TO BE VERY CONSISTENT WITH
THIS TIMING SO HAVE INCREASED POPS TO LIKELY DURING THIS TIME. FIRST
STARTING ACROSS THE NORTHWEST COUNTIES OF THE CWA MID
AFTERNOON...AND THEN MOVING TO THE SOUTHEAST THROUGH THIS EVENING.
THIS SYSTEM STILL LOOKS STRONG ENOUGH TO WARRANT A SLIGHT RISK FOR
SEVERE /PER SPC DAY ONE OUTLOOK/ WITH THE MAIN THREATS BEING
DAMAGING WIND GUSTS AND HAIL.

BY THIS AFTERNOON LOW LEVEL WINDS WILL BECOME SWLY AHEAD OF THE
UPPER TROUGH WHICH WILL MAINTAIN RICH LOW LEVEL MOISTURE /UPPER
60S-LOW 70F DEWPOINTS/ IN THE PRE-FRONTAL WARM SECTOR. STEEPER
MID-LEVEL LAPSE RATES ARE FORECAST TO SPREAD ACROSS THE AREA THUS
CONTRIBUTING TO 2500-3000 J/KG MLCAPE WHERE DIABATIC WARMING OF THE
SFC LAYER OCCURS.

FRONTAL BOUNDARY APPEARS TO SIGNIFICANTLY WEAKEN AS IT DROPS ACROSS
THE AREA THIS EVENING AND EVENTUALLY STALL OUT OVER SOUTHERN INDIANA
BY 12Z WEDNESDAY MORNING.

AS FOR TEMPERATURES...STUCK WITH A MOS BLEND FOR TODAY...EVEN CONSIDERING THE
CLOUDS AND PRECIPITATION CHANCES...DECENT WARM SWLY FLOW SHOULD
HELP TEMPERATURE ACHIEVE HIGHS IN THE MID TO UPPER 80S. WENT
SLIGHTLY WARMER FOR LOWS TONIGHT IN THE UPPER 60S.

&&

.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...

ISSUED AT 259 AM EDT TUE AUG 19 2014

THE SHORT TERM PERIOD..AND ACTUALLY THROUGH MUCH OF THE END OF THE
WEEK WILL BE PLAGUED BY A PESKY MEANDERING FRONTAL BOUNDARY THAT
WILL CONTINUALLY DRIFT NORTH AND SOUTH OF THE FORECAST AREA AS
ONE UPPER LEVEL DISTURBANCE AFTER ANOTHER RIDES
THROUGH...PROVIDING ON/OFF SCATTERED SHOWER AND THUNDERSTORMS.
WEDNESDAY ACTUALLY LOOKS LIKE THE DRIEST DAY OF THE PERIOD WITH
THE BOUNDARY FORECAST TO BE FAR ENOUGH SOUTH OF THE AREA THAT ONLY
COUNTIES ACROSS THE SOUTHERN HALF OF THE CWA HAVE A SLIGHT CHANCE
FOR STORMS THAT DAY. HIGHER CHANCES RETURN WEDNESDAY NIGHT AND
THURSDAY AS THE BOUNDARY LIFTS BACK NORTHWARD.

LAPSE RATES/DEEP LAYER SHEAR CONTINUE TO SUGGEST ORGANIZED
CONVECTION POSSIBLE WEDNESDAY AND THURSDAY WITH HEAVY RAINFALL ALSO
A THREAT WITH PRECIPITABLE WATERS APPROACHING 2 INCHES BY THURSDAY.
BASED ON GOOD MODEL CONTINUITY AND CONSENSUS BUMPED UP POPS TO JUST
SHY OF LIKELY DURING THIS TIME.

&&

.LONG TERM /FRIDAY THROUGH TUESDAY/...
ISSUED AT 247 AM EDT TUE AUG 19 2014

MODELS DEPICT PERHAPS THE WARMEST STRETCH OF THE SEASON THUS FAR FOR
THE COMING WEEKEND AS AN UPPER LEVEL RIDGE STRENGTHENS OVER THE
LOWER MISSISSIPPI AND OHIO VALLEYS. THIS MAY BE THE CLOSEST CALL YET
THIS SUMMER FOR THE ELUSIVE 90 DEGREE MARK AT INDIANAPOLIS. THAT
SAID...SEVERAL FACTORS WILL HAVE A HAND IN DETERMINING WHETHER OR
NOT WE GET THERE. WHILE SUMMER BEGAN ON QUITE A WET NOTE WITH ONE OF
THE TOP 15 WETTEST JUNES...WHICH HAS LIKELY CONTRIBUTED AT LEAST IN
SOME SMALL PART TO THE LACK OF HEAT THUS FAR...THE ATMOSPHERE HAS
REVERSED ITSELF SOMEWHAT SINCE THE START OF JULY...AND INDIANAPOLIS
IS ROUGHLY TWO AND A HALF INCHES BELOW NORMAL ON PRECIP SINCE
THEN...OR AROUND THE SAME AMOUNT THAT JUNE WAS ABOVE NORMAL.
HOWEVER...THE GUIDANCE DEPICTS A MOIST AIRMASS WITH DEWPOINTS
PUSHING THE LOW TO MID 70S AT TIMES. ADDITIONALLY...WHILE THE
FORECAST WILL ONLY CARRY POPS INTO SATURDAY...THE PERIPHERY OF THE
RIDGE...WHERE CONVECTION MAY OCCUR IN A RING OF FIRE STYLE...AND THE
CORRIDOR WHERE ANY ORGANIZED CONVECTIVE COMPLEXES MAY TRACK...WILL
NOT BE THAT FAR NORTH OF THE AREA...AND THIS COULD COMPLICATE
MATTERS AS WELL. IF SOME DIURNAL CONVECTION MANAGES TO OCCUR DESPITE
THE QUITE WARM MIDLEVEL TEMPERATURES PUSHING 10C...THAT WOULD ALSO
POTENTIALLY WORK AGAINST THE HEAT. WILL BE INTERESTING TO SEE HOW
CLOSE WE GET TO 90 OR IF WE MANAGE TO FINALLY BREACH THE MARK. IF IT
OCCURS THIS WEEKEND...IT WILL BE THE LATEST FIRST 90 DEGREE DAY
SINCE 1960...WHEN 90 WAS NOT REACHED UNTIL SEPTEMBER FIRST. THIS IS
OF COURSE EXCLUDING 2004...THE ONLY YEAR ON RECORD THUS FAR WITHOUT
A 90 DEGREE READING.

&&

.AVIATION /DISCUSSION FOR THE 19/06Z TAFS/...
ISSUED AT 1250 AM EDT TUE AUG 19 2014

CONDITIONS WILL CONTINUE DETERIORATE TO IFR OR WORSE AT MOST SITES
OVERNIGHT BEFORE RETURNING TO VFR BY TUESDAY AFTERNOON.

FOG IS ALREADY DEVELOPING IN A MOIST AIRMASS. EXPECT FOG AND STRATUS
TO CONTINUE TO BECOME MORE WIDESPREAD ONCE AGAIN TONIGHT. SIMILAR TO
YESTERDAY WENT IFR OR LOWER AT ALL SITES BUT KIND...WHERE URBAN HEAT
ISLAND EFFECTS SHOULD KEEP CONDITIONS IN MVFR CATEGORY.

FOG AND STRATUS WILL BURN OFF BY 15Z OR SO. THUNDERSTORMS ARE
POSSIBLE TUESDAY AFTERNOON. FOR NOW HAVE ADDED A VCTS MENTION AFTER
20Z OR SO.


&&

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

$$

SYNOPSIS...SMF
NEAR TERM...SMF
SHORT TERM...SMF
LONG TERM...NIELD
AVIATION...50

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