[MCD] SWOMCD

Wed Jun 21 19:29:18 UTC 2006

ACUS11 KWNS 211928
SWOMCD
SPC MCD 211928 
OHZ000-MIZ000-INZ000-ILZ000-212100-

MESOSCALE DISCUSSION 1278
NWS STORM PREDICTION CENTER NORMAN OK
0228 PM CDT WED JUN 21 2006

AREAS AFFECTED...NE IL...NRN IND...NW OH...SRN LOWER MI

CONCERNING...SEVERE THUNDERSTORM WATCH 527...

VALID 211928Z - 212100Z

THUNDERSTORM INITIATION APPEARS LIKELY OVER THE NEXT HOUR OR TWO
ACROSS THE I-80 CORRIDOR IN NRN IL...NRN IND AND NW OH. AN ISOLATED
TORNADO THREAT ALONG WITH LARGE HAIL AND WIND DAMAGE WILL BE
POSSIBLE WITH THE STRONGER CELLS AS THE STORMS DEVELOP AND INCREASE
IN INTENSITY. A WW WILL LIKELY BE NEEDED BY 21Z ACROSS THE REGION.

LATEST SFC ANALYSIS SHOWS A WARM FRONT LOCATED ACROSS SRN WI...SRN
LOWER MI INTO WCNTRL OH. SOUTH OF THE BOUNDARY...SFC DEWPOINTS IN
THE LOWER 70S F ARE CONTRIBUTING TO STRONG INSTABILITY WITH MLCAPE
VALUES RANGING FROM 3000 TO 4000 J/KG. VISIBLE SATELLITE IMAGERY
SHOWS THE CUMULUS FIELD EXPANDING ALONG THE INSTABILITY AXIS. THE
CAPPING INVERSION IS VERY WEAK ACCORDING TO OBJECTIVE ANALYSIS AND
STORM INITIATION APPEARS INCREASINGLY LIKELY THIS AFTERNOON. IN
ADDITION...A 70 KT MID-LEVEL JET IS LOCATED OVER NE IL AND IS
RESULTING IN STRONG VERTICAL SHEAR PROFILES FAVORABLE FOR SUPERCELLS
AND BOW ECHOES. AS STORMS INITIATE...RAPID DEVELOPMENT SHOULD OCCUR
DUE TO THE STRONG INSTABILITY. STEEP LAPSE RATES AND STRONG
LOW-LEVEL FLOW WILL BE FAVORABLE FOR AN ISOLATED TORNADO THREAT WITH
LARGE HAIL AND WIND DAMAGE ALSO POSSIBLE. A MORE SUBSTANTIAL AND
WIDESPREAD WIND DAMAGE THREAT MAY DEVELOP BY EARLY EVENING IF A
LINEAR MCS AND ASSOCIATED COLD POOL CAN ORGANIZE AND MOVE QUICKLY
EWD ACROSS THE REGION.

..BROYLES.. 06/21/2006

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...CLE...ILN...DTX...IWX...GRR...IND...LOT...ILX...DVN...

40438437 40058863 40728938 41548931 41968861 42238654
42228419 41368355 