Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 260816
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
416 AM EDT TUE AUG 26 2014

.SYNOPSIS...
ISSUED AT 413 AM EDT TUE AUG 26 2014

A COLD FRONT WILL SLOWLY DRIFT SOUTH OVER THE NEXT 24 HOURS
BRINGING ADDITIONAL CHANCES FOR SHOWERS AND THUNDERSTORMS. AHEAD
OF THE FRONT...ANOTHER HOT AND HUMID DAY WILL BE IN STORE WITH
HIGHS INTO THE UPPER 80S PRIOR TO ANY STORMS. ALONG THE FRONT
HIGHS WILL CLIMB INTO THE LOWER 80S AS A RESULT OF INCREASED CLOUD
COVER AND RAIN. LOWS TONIGHT WILL DROP INTO THE MIDDLE 60S.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 413 AM EDT TUE AUG 26 2014

BACK EDGE OF DEPARTING WAVE WAS WORKING ACROSS WESTERN PARTS OF THE
AREA. IN ITS WAKE...VSBYS WERE RAPIDLY DROPPING WITH VALPARAISO AND
KNOX NOW SHOWING AT PATCHY...LOCALLY DENSE FOG. WOULD EXPECTED THIS
TREND TO EXPAND EAST AS CLEARING OCCURS. SOME CONCERN THAT DENSE FOG
COULD BECOME MORE WIDESPREAD ALONG AND WEST OF ROUTE 15 BUT FOR NOW
WILL GO WITH PRE 1ST PERIOD OF PATCHY FOG AND MONITOR.

COLD FRONT WILL SLOWLY SAG SOUTH INTO THE REGION TODAY BRINGING
ANOTHER SHOT AT SHOWERS AND THUNDERSTORMS. HIGH RES MODELS ALL
SUGGEST CONVECTIVE DEVELOPMENT SOMEWHERE FROM CENTRAL ILLINOIS INTO
NW PARTS OF THE FORECAST AREA TOWARDS 12Z WITH THIS THEN EXPANDING
SE WITH TIME THROUGH LATE AFTERNOON. AS OF WRITING THIS...A FEW
CELLS WERE RAPIDLY DEVELOPING IN EASTERN IOWA WHICH COULD BE THE
STARTS OF THINGS TO COME. WATER VAPOR LOOP SHOWING SOME INDICATIONS
OF A WAVE MOVING ACROSS EASTERN IOWA INTO ILLINOIS THAT COULD GET
THINGS MOVING. SPC MESOANALYSIS SHOWING 3500-4000 J/KG OF MOST
UNSTABLE CAPE OVER ILLINOIS AND AREAS OF WEAK CONVERGENCE. HAVE
ADJUSTED CHANCES FOR PRECIP TO FOCUS MAINLY NW AT THE START OF THE
PERIOD BUT HELD IN CHC RANGE FOR NOW. AS THE MORNING PROGRESSES ANY
CONVECTION SHOULD EITHER EXPAND OR DEVELOP FURTHER SOUTHEAST WHERE
HEATING WILL BE MORE FOCUS AND PRONOUNCED. BY 18Z A SWATH OF
MODERATE TO STRONG INSTABILITY SHOULD BE IN PLACE ACROSS SE HALF OF
THE AREA WHERE TEMPS SHOULD CLIMB INTO THE UPPER 80S TO NEAR 90. AS
HAS BEEN THE CASE...SHEAR PROFILES RATHER ANEMIC LENDING TO SLOW
MOVING STORMS CAPABLE OF HEAVY RAIN AND MAYBE AN ISOLATED STRONG
WIND GUST AS STORMS COLLAPSE.

FRONT SHOULD RESIDE ACROSS THE SOUTHERN COUNTIES THIS EVENING AND
THEN STALL OUT. MODELS HAD HINTED AT ADDITIONAL STORMS DEVELOPING
OVERNIGHT BUT NOT SURE EXACTLY WHERE BEST CONVERGENCE WILL EXIST SO
WILL DOWN PLAY SOMEWHAT AND KEEP IN SLGT CHC TO CHC RANGE.


&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 413 AM EDT TUE AUG 26 2014


CDFNT OVER WI/IA THIS MORNING IS EXPECTED TO BECOME MORE E-W
ORIENTED AND MOVE TO JUST SOUTH OF OUR CWA BY WED MORNING. A FEW
POST FRONTAL SHOWERS/TSTMS STILL PSBL WED AS A SHRTWV CURRENTLY OVER
SASK/MT DROPS SE ACROSS THE GRTLKS. SFC HIGH MOVG INTO THE UPR
GRTLKS WED WILL ADVECT COOLER/DRIER AIR INTO THE AREA BRINGING AN
END TO THE RECENT MUGGY CONDITIONS WITH HIGHS EXPECTED NEAR NORMAL
IN THE U70S/L80S AND DWPTS FALLING BACK TO THE L-M60S. SFC RIDGE
CROSSING THE CWA SHOULD PROVIDE DRY CONDITIONS WED NIGHT.
RADIATIONAL COOLING MAY BE LIMITED SOME BY HIGH CLOUDS SPILLING E-SE
FROM CONVECTION OVER THE PLAINS IN RESPONSE TO CUT-OFF LOW CROSSING
THE ROCKIES... THUS LOWS ONLY EXPECTED TO FALL INTO THE U50S NE TO
THE M60S SW.

ROCKIES UPR LOW WILL SHEAR OUT TO AN OPEN WAVE OVER THE HIGH PLAINS
THU-THU NGT. RIDGING ALOFT IN ADVANCE OF THIS SYSTEM SHOULD RESULT
IN CONTD DRY WX ACROSS OUR AREA THU... BUT BY THU NGT STALLED SFC
BOUNDARY OVER THE OH VALLEY IS EXPECTED TO LIFT NORTH IN RESPONSE
TO APCHG UPR TROF... PSBLY CAUSING SHOWERS/TSTMS IN OUR AREA.

UPR RIDGE WILL MOVE EAST OF THE AREA ON FRIDAY BUT RETURN OF
MOIST/UNSTABLE AIRMASS MAY ALLOW FOR SOME AFTN TSTMS TO DEVELOP. NRN
STREAM SHRTWV MOVG THROUGH ZONAL FLOW ACROSS CANADA IS EXPECTED TO
PUSH A CDFNT SOUTH INTO OUR CWA SATURDAY WHICH WILL LIKELY STALL
OVER THE AREA AS IT AWAITS PLAINS TROF AND ASSOCIATED SFC WAVE ALONG
THE FRONT TO MOVE THROUGH. THIS WILL KEEP STORM CHANCES THROUGH THE
WEEKEND... THOUGH CONDITIONS MAY DRY OUT/WARM UP ON LABOR DAY AS THE
SHRTWV MOVES EAST TO THE LWR GRTLKS AND ANOTHER SOMEWHAT STRONGER
SHRTWV/CDFNT MOVES EAST ACROSS THE PLAINS.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 132 AM EDT TUE AUG 26 2014

WEAK AREA OF CONVERGENCE WAS LOCATED VICINITY OF KSBN AND COULD
PROVIDE FOCUS FOR WIDELY SCATTERED SHOWERS/STORMS THE REMAINDER OF
THE NIGHT. HAVE LEFT VCSH MENTION FOR NOW AS SETUP NOT OVERLY
IMPRESSIVE. AS NOTED BY PAST SHIFT SOMEWHAT BETTER CHANCES FOR
SHOWERS/STORMS AND FLGT IMPACTS MAY TAKE SHAPE SOUTH OF KSBN AND
IN AREA OF KFWA AS BOUNDARY SINKS SLOWLY SOUTH AND INSTABILITY
INCREASES AND FOCUSES IN THIS AREA. VCTS STILL WARRANTED BUT HAVE
WRAPPED UP THE BEST CHANCES AROUND 3Z. ANY STORMS THAT DO FORM
THROUGH THE PERIOD WILL BE SLOW MOVING WITH LOCALIZED VSBY IMPACTS
THAT WILL MAY BE TOUGH TO FULLY CAPTURE IN TAFS.


&&

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

$$

SYNOPSIS...FISHER
SHORT TERM...FISHER
LONG TERM...JT
AVIATION...FISHER


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