AREAS AFFECTED...NERN/E-CNTRL IL...W-CNTRL IND
CONCERNING...SEVERE THUNDERSTORM WATCH 258...
VALID 062207Z - 062300Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 258
CONTINUES.
SUMMARY...SLOW-MOVING TSTM CLUSTER OVER NERN/E-CNTRL IL MAY
PROPAGATE SEWD INTO PORTIONS OF W-CNTRL IND...SE OF WW 258. THIS
AREA IS BEING MONITORED FOR A POSSIBLE SEVERE TSTM WATCH ISSUANCE.
DISCUSSION...TSTM CLUSTER APPROACHING THE I-74 CORRIDOR IN E-CNTRL
IL IS GRADUALLY DEVELOPING SEWD ALONG A QUASI-STATIONARY FRONT
ANALYZED FROM NEAR LAF TO LUK. CORES HAVE ALSO STRENGTHENED ALONG A
REMNANT OUTFLOW/WEAK CONFLUENCE AXIS EXTENDING SWD THROUGH ERN IL.
ON THE FRINGE OF STRONG INSTABILITY WITH MODIFIED 18Z ILX RAOB
SUGGESTIVE OF MLCAPE AROUND 3500 J/KG...BUT MODEST DEEP-LAYER
SHEAR...STRENGTH OF THE SURFACE COLD POOL MAY BE SUFFICIENT TO
MAINTAIN THE CLUSTER EVOLVING INTO W-CNTRL IND. BUT WITH CONVECTIVE
OUTFLOW ALREADY SURGING 10-15 NM AHEAD OF THE WRN PORTION OF THE
CLUSTER...PRIMARY THREATS SHOULD REMAIN LOCALLY DAMAGING WINDS AND
MARGINALLY SEVERE HAIL WITH LEADING CONVECTION.
..GRAMS.. 05/06/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...IWX...IND...LOT...ILX...
LAT...LON 40928787 40928733 40768682 40508648 40038627 39398661
39148714 39148759 39308791 39458796 40588804 40928787
