MESOSCALE DISCUSSION 0999
NWS STORM PREDICTION CENTER NORMAN OK
0316 PM CDT SUN MAY 30 2004
AREAS AFFECTED...ERN IA...NRN IL...SRN WI
CONCERNING...TORNADO WATCH 332...
VALID 302016Z - 302215Z
CONTINUE REMAINING VALID PORTION OF WW. NEW WW WILL BE NEEDED
ACROSS THE REMAINDER OF NORTHERN ILLINOIS/SOUTHERN WISCONSIN WITHIN
NEXT HOUR OR TWO.
INCREASING/INTENSIFYING CONVECTION IS ONGOING IN INSTABILITY AXIS
ALONG/AHEAD OF INITIAL WEAK COLD FRONT ADVANCING INTO THE MID/UPPER
MISSISSIPPI VALLEY. MOST INTENSE THUNDERSTORMS REMAIN
NEAR/SOUTHEAST OF WAVE AT INTERSECTION OF FRONT AND RETREATING
OUTFLOW BOUNDARY...NOW NORTHEAST OF KEOKUK IA. THIS ACTIVITY IS
BEING SUPPORTED BY FORCING IN EXIT REGION OF CYCLONIC POLAR JET
STREAK NOSING INTO THE MISSOURI OZARKS. ENHANCED LOW-LEVEL
HODOGRAPHS NEAR UPPER JET AXIS CONTINUE TO SUPPORT POTENTIAL FOR
STRONG TORNADOES WITH ONGOING SUPERCELLS...IN VERY MOIST BOUNDARY
LAYER WITH 70F DEW POINTS AND CAPE UP TO 2000 J/KG.
FAVORABLE LARGE-SCALE FORCING FOR UPWARD VERTICAL MOTION MAY SUPPORT
UPSCALE DEVELOPMENT INTO LARGER MESOSCALE CONVECTIVE SYSTEM
NORTHEASTWARD ACROSS NORTHERN ILLINOIS THROUGH 31/00Z.
..KERR.. 05/30/2004
ATTN...WFO...LOT...ILX...MKX...LSX...DVN...ARX...
41489128 42059099 42989089 43668982 43248803 42338792
41798796 40758882 39808988 40129156
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