AREAS AFFECTED...CNTRL IL/IND...SWRN OH
CONCERNING...SEVERE THUNDERSTORM WATCH 628...630...
VALID 072022Z - 072115Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH
628...630...CONTINUES.
SUMMARY...CONVECTION IS BLOSSOMING ALONG/BEHIND COLD FRONT FROM NERN
MO TO CNTRL IL...WITH REMNANT CONVECTION PERSISTING ALONG THE
OUTFLOW BOUNDARY EXTENDING INTO SWRN OH. PARTS OF WW 628 WILL LIKELY
BE REPLACED WITH A NEW WW PRIOR TO 21Z.
DISCUSSION...STRENGTHENING LARGE-SCALE ASCENT APPEARS TO BE YIELDING
RAPIDLY INCREASING CONVECTIVE COVERAGE FROM NERN MO TO CNTRL IL. 20Z
SURFACE ANALYSIS PLACED A GRADUALLY ACCELERATING COLD FRONT FROM JLN
TO SPI...INTERSECTING A W/E-ORIENTED OUTFLOW BOUNDARY TO IND TO 25 S
DAY. ALTHOUGH MOST OF THE UPSTREAM DEVELOPMENT APPEARS TO BE
OCCURRING ON THE COOL SIDE OF THE FRONT...THE COMBINATION OF
BUOYANCY/SHEAR IS ROBUST IN THE WARM SECTOR. WITH TSTMS PERSISTING
ALONG THE OUTFLOW BOUNDARY AFTER 22Z...A REPLACEMENT WW APPEARS TO
BE THE MOST PRUDENT COURSE OF ACTION.
..GRAMS.. 09/07/2012
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...ILN...IND...LOT...ILX...LSX...
LAT...LON 40638793 40378712 40078565 39768438 39608390 39138398
38918426 38938544 38928773 39178943 39359012 39559032
39939032 40289028 40759010 40978955 41008903 40638793
