AREAS AFFECTED...PORTIONS OF ERN IA...FAR ERN MO...MUCH OF
IL...CNTRL/WRN IND
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 021805Z - 022000Z
PROBABILITY OF WATCH ISSUANCE...20 PERCENT
SUMMARY...A FEW STORMS MAY CONTAIN MARGINALLY SVR HAIL/WIND THIS
AFTERNOON. THE LIMITED POTENTIAL OF SVR STORMS WILL LIKELY PRECLUDE
THE ISSUANCE OF A WW.
DISCUSSION...RECENT WATER VAPOR IMAGERY INDICATES A RIBBON OF
MID/UPPER ASCENT IN ASSOCIATION WITH DCVA ATTENDANT TO AN UPPER JET
OVER THE SWRN FLANK OF THE BROAD CYCLONIC CIRCULATION ENVELOPING THE
NERN QUARTER OF THE CONUS. BENEATH THIS ASCENT...TOWERING CUMULUS
CONTINUES TO DEVELOP INVOF /1/ A SFC TROUGH AXIS THAT IS SHIFTING
SEWD ACROSS CNTRL/ERN IA...AND /2/ A SFC DEWPOINT GRADIENT EXTENDING
FROM FAR NERN IA ACROSS FAR SWRN WI AND INTO NRN IL AND NRN IND.
THESE FEATURES WILL SERVE AS THE FOCI FOR CONVECTIVE DEVELOPMENT
INTO THE AFTERNOON.
DESTABILIZATION OWING TO AREAS OF INSOLATION/DIABATIC HEATING AND
THE AFOREMENTIONED MID/UPPER ASCENT WILL LIKELY ALLOW CONVECTION TO
DEEPEN WHILE TRACKING SEWD/ESEWD. WHILE LOW-LEVEL MOISTURE IS RATHER
MEAGER -- I.E. SFC DEWPOINTS IN THE UPPER 40S AND THE LOWER 50S --
STEEP LAPSE RATES ASSOCIATED WITH COLD MID-LEVEL TEMPERATURES /-20C
TO -18C AT 500 MB PER 12Z RAOBS/ WILL SUPPORT MARGINAL
DESTABILIZATION WITH MLCAPE VALUES OF 300-800 J/KG /HIGHEST OUTSIDE
OF CONVECTIVE DEBRIS CLOUDS OVER CNTRL IL/. AND...WITH
MODERATE/STRONG WNWLY/NWLY FLOW OVER THE AREA...20-30 KT OF
EFFECTIVE BULK SHEAR WILL SUPPORT OCCASIONALLY ORGANIZED CONVECTIVE
STRUCTURES INCLUDING MULTICELL STORMS WITH A THREAT FOR SVR
WIND/HAIL. HOWEVER...THE LACK OF RICHER LOW-LEVEL MOISTURE AND LACK
OF GREATER INSTABILITY SHOULD LIMIT THE POTENTIAL OF SVR STORMS.
STORMS WILL DECREASE IN NUMBER/INTENSITY AS NOCTURNAL STABILIZATION
COMMENCES EARLY THIS EVENING.
..COHEN/CARBIN.. 06/02/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...IND...PAH...LOT...ILX...LSX...DVN...
LAT...LON 40439195 41529196 42369164 42359061 41778894 41308669
40908561 39828566 38828659 38468802 38348890 38278995
38899112 40439195
