Area Forecast Discussion
Issued by NWS Northern Indiana

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000
FXUS63 KIWX 270542
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
142 AM EDT SUN JUL 27 2014

.SYNOPSIS...
ISSUED AT 140 AM EDT SUN JUL 27 2014

THERE IS A CHANCE OF SHOWERS AND THUNDERSTORMS TONIGHT AS A COUPLE
OF WEAK UPPER LEVEL DISTURBANCES INTERACT WITH A FRONTAL BOUNDARY
ACROSS THE AREA. THERE IS A BETTER CHANCE OF SHOWERS AND
THUNDERSTORMS ON SUNDAY AS A STRONGER UPPER LEVEL DISTURBANCE
DROPS INTO THE WESTERN GREAT LAKES. THE COLD FRONTAL BOUNDARY
ASSOCIATED WITH THIS DISTURBANCE WILL PROVIDE COOLER THAN NORMAL
CONDITIONS THROUGH MUCH OF NEXT WEEK.

&&

.UPDATE...
ISSUED AT 835 PM EDT SAT JUL 26 2014

A CONVECTIVELY ENHANCED VORT MAX ASSOCIATED WITH ONGOING MCS FROM
CENTRAL INDIANA INTO SOUTHEAST ILLINOIS WILL CONTINUE TO TRACK
EAST SOUTHEAST INTO SOUTHERN INDIANA OVERNIGHT. BULK OF SHOWERS
AND THUNDERSTORMS SHOULD REMAIN SOUTH OF THE FORECAST AREA
ALTHOUGH RECENT UPSWING IN CONVECTION HAS BEEN NOTED ON NORTHERN
PERIPHERY OF THIS MCS ACROSS TIPPECANOE INDIANA AND CLINTON
INDIANA COUNTIES. CURRENT EXPECTATION IS THAT CONVECTION MAY
STRUGGLE NORTHWARD INTO THE LOCAL AREA GIVEN GREATER DEGREE OF CIN
FOR LOW LEVEL PARCELS EXHIBITED ON 00Z ILX/DVN RAOBS AND LATEST
REGIONAL AMDAR SOUNDINGS. HAVE MAINTAINED OVERALL IDEA OF SOUTH TO
NORTH POP GRADIENT TONIGHT (HIGHEST POPS SOUTH)...BUT HAVE
SLIGHTLY REDUCED POPS GIVEN RECENT OBSERVATIONAL TRENDS. OVERALL
SEVERE THREAT APPEARS TO HAVE LESSENED SOMEWHAT BUT WILL MAINTAIN
LOW CHANCE TSRA POPS DURING THE OVERNIGHT HOURS IN WAKE OF
AFOREMENTIONED MCS...WITH BROAD LOW LEVEL ISENTROPIC UPGLIDE
CONTINUING ACROSS ESPECIALLY SOUTHERN PORTIONS OF THE FORECAST
AREA.

&&

.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 306 PM EDT SAT JUL 26 2014

ISO-SCT ELEVATED CONVECTION STARTING TO BUBBLE UP ACROSS THE AREA
THIS AFTERNOON ALONG A HYBRID WARM FRONT/TRIPLE POINT...AND IN
ADVANCE OF WEAK SHORTWAVE/SFC TROUGH APPROACHING FROM WI.
2500-3500 J/KG MUCAPE RESERVOIR FILTERING NEWD IN PERSISTENT WAA
REGIME ON EASTERN FRINGE OF IMPRESSIVE EML (AMID 50 KNOTS OF DEEP
LAYER SHEAR) HINTS AT AN ISOLATED LARGE HAIL RISK...WITH A LESSER
WIND THREAT INITIALLY PER PRONOUNCED ML/SB CIN.

ATTENTION FOR THIS EVENING INTO THE EARLY OVERNIGHT WILL TURN TO
POSSIBLE UPSCALE GROWTH/ORGANIZATION OF A CONVECTIVE COMPLEX FCST TO
FORWARD PROPAGATE EWD INTO THE NORTHERN OH VALLEY. SCATTERED
MULTICELL CONVECTION HAS ALREADY BEGUN TO FORM ACROSS NORTHERN MO IN
ADVANCE OF A REMNANT MCV...WITH AMPLE MOISTURE/CAPE AND FLOW ALOFT
FAVORABLE FOR ORGANIZATION EAST. WEST-TO-EAST ORIENTATION OF SBCAPE
GRADIENT ACROSS CENTRAL IL TO THE IA/MO BORDER UNDER STRONG WNW FLOW
ALOFT SUGGEST THAT THE BULK THIS CONVECTIVE SYSTEM (SEVERE WINDS)
WILL FOCUS SOUTH OF THE AREA THROUGH THE SOUTHERN TWO THIRDS OF
INDIANA INTO SW OHIO. STILL TOO CLOSE FOR COMFORT FOR AREAS SOUTH
OF HWY 30 IN INDIANA WHERE A LOW WIND RISK REMAINS. AS MENTIONED
IN THE PREV DISCUSSION...THERE IS SOME CONCERN FOR
BACKBUILDING/TRAILING CONVECTION AND ISOLATED FLOODING OFF OF A
STRATIFORM BUBBLE LATER TONIGHT ACROSS MAINLY THE SOUTHERN HALF OF
THE FA WHICH WILL CONTINUE TO BE ADDRESSED IN THE HWO.

COMPACT/STRONG CIRCULATION NOW OVER FAR SOUTHERN MANITOBA WILL OPEN
SEWD INTO THE UPPER MIDWEST TONIGHT AND INTO THE WESTERN GREAT LAKES
TOMORROW. STRONG MID LEVEL PVA/CYCLONIC FLOW WITH 100 METER HEIGHT
FALL CENTROID INTO SRN LOWER MI BY 00Z...AND FAVORABLE LEFT EXIT
JET SUPPORT INTO MAINLY NORTHERN/EASTERN PORTIONS OF THE FA...WILL
ALLOW A WEAK SFC REFLECTION TO STRENGTHEN A BIT INTO NRN IN/LOWER
MI TOMORROW. THIS SHOULD SUPPORT SCT SHOWERS/STORMS/UNSETTLED
WEATHER ESPECIALLY ACROSS NORTHERN/EASTERN ZONES BY LATE
MORNING/AFTERNOON GIVEN SOME DIURNAL RECOVERY...ALTHOUGH LEFTOVER
MOISTURE QUALITY AND CLOUD DEBRIS MAY BE SOMEWHAT LIMITED FOR
WIDESPREAD HVY RAIN/SVR WX. STILL IF SOME HEATING IS REALIZED
STORMS COULD BECOME SEVERE ALONG A TRAILING SECONDARY CDFNT GIVEN
STRONG KINEMATICS (BEST CHANCES EAST OF I-69).

&&

.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 306 PM EDT SAT JUL 26 2014

LEAD SW TROUGH OVR MB THIS AFTN CONT SEWD SHRT TERM AND ROUND EWD
THROUGH BASE OF OF LONG WAVE TROUGH DVLPG EAST OF JAMES BAY SUN
NIGHT. A BRIEF SHRA PSBL NE HALF SUN EVE OTRWS XPC SWD WRAPPING
COOL/DRY CANADIAN AIRMASS WILL CURTAIL ANY ADDNL SHRA THREAT INTO
MON. THUS WILL WHITTLE POPS FURTHER.

LTL SENSIBLE WX CONCERN THEREAFTER AS NEG HGT ANOMALY CNTRD NR
JAMES BAY LOCKS IN. THUS W/NWRLY LL FLW CONTG ACRS THE LAKES...
UNSEASONABLY COOL TEMPS TO START ON MON WILL BE SLOW TO MODERATE
W/DOWNRIGHT COMFORTABLE TEMPS XPCD FOR LT JULY/EARLY AUG.

&&

.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 136 AM EDT SUN JUL 27 2014

TRANSIENT BR/FG WITHIN STABLE/MOIST BOUNDARY LAYER ACROSS NORTHERN
INDIANA TO RESULT IN AT LEAST TEMPO FUEL ALT CONDITIONS THIS AM.
TIMING OF CONVECTION UPSTREAM ASSOCIATED WITH VIGOROUS VORTEX
ACROSS NORTHERN MN WARRANTS AT MINIMUM VCTS MIDDAY/EARLY
AFTERNOON. LATER FORECAST ITERATIONS TO FURTHER ASSESS
TIMING/PROBABILITY OF OCCURRENCE FOR POSSIBLE TEMPO INCLUSION.
LATE DAY FROPA TO AFFORD MOIST/WELL MIXED BOUNDARY LAYER SUN
NIGHT...FOR AT LEAST LIGHT BR AND MORE LIKELY LOW STRATUS DECK
DEVELOPMENT.

&&

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

$$

UPDATE...MURPHY
SYNOPSIS...MARSILI
SHORT TERM...STEINWEDEL
LONG TERM...T
AVIATION...MURPHY


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