Wednesday, June 12, 2013

Mesoscale Discussion 15:39:15.5579145

AREAS AFFECTED...PORTIONS OF NERN IL...SRN LAKE MICHIGAN...SWRN
LOWER MI...NRN IND...NWRN OH

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 122038Z - 122215Z

PROBABILITY OF WATCH ISSUANCE...95 PERCENT

SUMMARY...A PDS SEVERE THUNDERSTORM WATCH WILL BE ISSUED BY 22Z.
TSTMS DEVELOPING ACROSS NERN IA...SWRN WI AND NWRN IL ARE EXPECTED
TO CONGEAL INTO AN ACCELERATING CONVECTIVE SYSTEM AND MOVE ESE
ACROSS THE DISCUSSION AREA DURING THE LATE AFTERNOON AND EVENING
HOURS. DAMAGING WINDS...SOME IN EXCESS OF 65 KTS...ARE LIKELY ALONG
WITH EMBEDDED MESOVORTEX/QLCS TORNADOES.

DISCUSSION...TSTMS DEVELOPING IN THE VICINITY OF A FRONTAL BOUNDARY
OVER NERN IA/SRN WI/NWRN IL WILL LIKELY CONTINUE TO INCREASE IN
COVERAGE DURING THE NEXT FEW HOURS...WITH CONVECTION EVOLVING INTO A
FORWARD PROPAGATING MCS AS IT MOVES ESE ALONG THE FRONTAL BOUNDARY
INTO NERN IL...NRN IND AND NWRN OH. FORCING FOR ASCENT ASSOCIATED
WITH A SHORTWAVE APPROACHING FROM THE WEST WILL FURTHER AID IN
UPSCALE GROWTH OVER THE NEXT FEW HOURS. AS STORMS BEGIN TO COALESCE
AROUND A GROWING COLD POOL AN EASTWARD ACCELERATION IS LIKELY.
DAMAGING WINDS...SOME IN EXCESS OF 65 KTS...WILL BE LIKELY ALONG
WITH EMBEDDED QLCS/MESOVORTEX TORNADOES.

..BUNTING/CARBIN.. 06/12/2013

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

ATTN...WFO...CLE...ILN...IWX...GRR...IND...LOT...ILX...MKX...

LAT...LON 40608839 41298857 42218852 42788816 42808798 42748752
42488669 42318626 42078551 41698476 41258373 40898359
40438360 40138379 40118457 40198515 40288603 40438732
40608842 40608839