Severe Thunderstorm Warning 33, NWS Chicago, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
300 AM CDT THU MAY 11 2000

MULTIPLE CHALLENGES WITH THIS PACKAGE.

ELEVATED CONVECTION ALONG SOUTHERN BOUNDARY OF CWA INDICATES LAPSE
RATES ALREADY STEEP EARLY THIS MORNING. AS LOW LEVEL JET CONTINUES
TO SURGE NORTHEASTWARD...EXPECT ATMOSPHERE TO BECOME INCREASINGLY
UNSTABLE...AND CONVECTION TO FIRE ANYWHERE FROM NEAR DMX EWD.
GOING FORECAST HAS THIS COVERED...SO WILL MAKE ONLY MINOR CHANGES.

TEMPERATURES A BIG CONCERN TODAY...AS CLOUD COVER MAY KEEP 80S AT
BAY. WITH ETA 850 PROG AT 20C AT 00Z FRIDAY...ANY SUN WILL SEND
TEMPERATURES SOARING WELL INTO THE 80S.

PROGS GIVE A STRANGE MIX OF SOLUTIONS FOR CONVECTION CHANCES ALONG
FRONT ON FRIDAY. AVN LOOKS MOST REALISTIC...WITH SUBSTANTIAL QPF IN
NE IL AS FRONT PASSES IN THE AFTERNOON AND PLOWS THROUGH 70F SURFACE
DEWPOINTS. ETA DRY AS A BONE WITH CAPES NEAR 3800 J/KG. WITH THIS
TYPE OF INSTABILITY...IT SEEMS EVEN WEAK CONVERGENCE ALONG THE FRONT
WOULD BE ENOUGH TO SET THINGS IN MOTION.

.CHI...NONE
BROWNING

SPSCHI
ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019-
111700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
600 AM CDT/EST THU MAY 11 2000

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA...

THERE IS A SLIGHT CHANCE FOR SEVERE THUNDERSTORMS BOTH TODAY AND
TONIGHT. THUNDERSTORMS WILL LIKELY FORM THIS MORNING OVER IOWA AND
NORTHWEST ILLINOIS...THEN SPREAD RAPIDLY EASTWARD. LARGE HAIL AND
DAMAGING WINDS AREA POSSIBLE.

ANOTHER ROUND OF THUNDERSTORMS WILL LIKELY FORM OVER WESTERN IOWA
TONIGHT...THEN MOVE RAPIDLY EASTWARD...POSSIBLY REACHING
NORTHCENTRAL AND NORTHEAST ILLINOIS BY THE EARLY MORNING HOURS. SOME
OF THESE STORMS COULD ALSO BE SEVERE.