000
FXUS63 KIWX 211737
AFDIWX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NORTHERN INDIANA
137 PM EDT TUE MAY 21 2013

.SYNOPSIS...
ISSUED AT 1042 AM EDT TUE MAY 21 2013

LOW PRESSURE OVER THE UPPER MIDWEST WILL TRACK EAST INTO THE GREAT
LAKES REGION TOMORROW. THIS SYSTEM WILL BRING INCREASING CHANCES
FOR SHOWERS AND THUNDERSTORMS TO THE AREA...MAINLY LATER TONIGHT
INTO WEDNESDAY. A FEW THUNDERSTORMS MAY BECOME STRONG TO SEVERE. A
FEW SHOWERS MAY LINGER INTO THURSDAY...WITH COOLER AND DRIER AIR
FORECAST TO SETTLE INTO THE REGION LATE THIS WEEK INTO THE
HOLIDAY WEEKEND.

&&

.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 442 AM EDT TUE MAY 21 2013

OUTFLW DOMINANT CONVN CONTS TO PROGRESS SLOWLY ACRS
WRN PORTION OF CWA THIS MORNING YET CONTS TO FESTER WITHIN AS YET
FVRBLY UNSTABLE LL THETA-E RIDGE. HWVR UPSTREAM STRATIFORM ACRS WRN
IN/ERN IL DECAYING RAPIDLY W/WARMING CLOUD TOPS NOTED IN IR AND
MARKS XPCD RAPID EWD DOWNTREND THROUGH DAYBREAK.

STABILIZATION OCCURRING IN WAKE OF THIS LINE AND SUSPECT LTL IF ANY
REDVLPMNT IN THE CARDS UNTIL VRY LT THIS AFTN/EARLY EVE IN ASSOCN/W
EWD TRANSLATION OF SFC LOW INTO NE WI BY 00Z. HWVR NWD REDVLPMNT OF
PREFERRED LL THETA-E RIDGE LIKELY DELAYED TO WELL AFT DARK TIMED
W/NWD EXPANSION OF LLJ TIED TO EJECTING CONV INDUCED SW TROUGH OUT
OF OK. THUS DELAYED OVERNIGHT RAMP TO PRIOR POPS TWD WINDOW OF
GREATER MODEL CONSENSUS IMPLIED FORCING AFT MIDNIGHT.

INBTWN XPC CLDS TO SCT OUT BY LT MORNING/EARLY AFTN W/ANOTHER VRY
WARM DAY IN STORE PER MODEST MIXING WITHIN LL THERMAL RIDGE.

&&

.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 442 AM EDT TUE MAY 21 2013

AN UPPER LOW WILL LIFT NORTHEAST WEDNESDAY...ACCOMPANIED BY A COLD
FRONT. THE RIGHT ENTRANCE REGION OF AN UPPER LEVEL JET WILL PASS
OVER THE SOUTHEAST PORTION OF THE FORECAST AREA WEDNESDAY INCLUDING
MOST OF NW OHIO. HOWEVER...GIVEN VERY LIMITED CAPE AND A RATHER
UNIDIRECTIONAL WIND PROFILE...CURRENT THINKING IS SEVERE STORM
POTENTIAL IS MARGINAL. MUCH COOLER AIR WILL SPREAD INTO THE AREA
BEHIND THE COLD FOR LATE THIS WEEK. FAVORED THE GFS MEAN ENSEMBLE
MOS WHICH HAS BEEN GENERALLY TRENDING A LITTLE COLDER LATE THIS
WEEK...OTHERWISE...HAS BEEN CONSISTENT FOR THE PAST FEW 00Z RUNS.
KEPT THE FORECAST DRY AFTER THURSDAY AS AN UPPER LEVEL RIDGE BUILDS
UPSTREAM.

&&

.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 136 PM EDT TUE MAY 21 2013

DEEP MIXING TO GREATER THAN 850MB PER RAP/NAM/GFS BUFKIT SOUNDINGS
HAS COMMENCED THIS AFTERNOON RESULTING IN GUSTS AOA 30 KTS BEING
REPORTED ACROSS MOST OF THE AREA. THESE WINDS WILL CONTINUE INTO THE
EARLY EVENING BEFORE WEAKENING NEAR SUNSET. CONVECTIVE CHANCES
REMAIN LOW THROUGHOUT THE DAY TODAY AS AIRMASS STABILIZATION FROM
MORNING CONVECTION SEEMS TO BE WINNING OUT. THUNDERSTORM CHANCES
WILL INCREASE TONIGHT AS VORT MAX ACROSS WESTERN OKLAHOMA AT 18Z
SWINGS UP INTO THE SOUTHERN GREAT LAKES. THE STORMS WILL MOVE INTO
THE AREA AFTER 06Z. IFR OR LOWER CIGS/VIS POSSIBLE WITH THESE
STORMS. LATER TAF ISSUANCES WILL ATTEMPT TO BETTER DISCERN THE
TIMING/IMPACT AT KFWA AND KSBN AS CONVECTIVE EVOLUTION EVOLVES.

&&

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

$$

SYNOPSIS...STEINWEDEL
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...BENTLEY


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