CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE
VALID 152312Z - 160015Z
PORTIONS OF NRN IL ARE BEING MONITORED FOR A POSSIBLE WW.
CONSIDERABLE UNCERTAINTY REGARDING TSTM INTENSITY/COVERAGE
EXISTS...BUT CONVECTIVE TRENDS ARE BEING CLOSELY MONITORED.
ISOLATED TSTMS HAVE DEVELOPED OVER THE PAST HR SW OF THE CHICAGO
METRO AREA...WITHIN A BROAD LOW-LEVEL WAA REGIME AHEAD OF A STRONG
CNTRL PLAINS CYCLONE. A LACK OF DISCERNABLE MESOSCALE BOUNDARIES IS
LEADING TO LARGELY UNFOCUSED DEVELOPMENT OF NEW
CONVECTION...YIELDING CONSIDERABLE UNCERTAINTY TO EVOLUTION AND
EVENTUAL COVERAGE OF THE POTENTIAL THREAT. HOWEVER...THE ENVIRONMENT
ACROSS THIS AREA IS STRONGLY SHEARED /0-1 KM BULK SHEAR NEAR 30 KTS
PER LOT VWP/...SUPPORTIVE OF DMGG WIND GUSTS AND PERHAPS A TORNADO
SHOULD CONVECTION CONTINUE TO INTENSIFY. FORECAST MODEL GUIDANCE
ALSO INDICATES LLJ SHOULD CONTINUE TO STRENGTHEN THROUGH AT LEAST
04Z...WHILE STORMS WILL HAVE THE POTENTIAL TO REMAIN NEAR SFC-BASED.
INSTABILITY REMAINS SOMEWHAT OF A LIMITING FACTOR /NEAR 1000 J/KG
MLCAPE PER RUC OBJECTIVE ANALYSIS/ AS WIDESPREAD STRATUS OBSERVED ON
VISIBLE SATELLITE LOOP HAS LIKELY LIMITED DIABATIC HEATING SOMEWHAT.
CONVECTIVE TRENDS WILL CONTINUE TO BE MONITORED FOR ISSUANCE OF A
POTENTIAL WW.
..ROGERS.. 04/15/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...MKX...DVN...
LAT...LON 41678750 41168765 40588772 40358867 40349024 41179038
42159006 42508929 42448813 42268780 41678750
