Severe Thunderstorm Warning 33, NWS Chicago, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO IL
330 AM CDT SUN JUL 8 2001

MAIN FCST PROBLEM THIS MRNG DEALS WITH POPS AND OVERALL CHANCES FOR
TSTMS.  CURRENTLY...RADAR AND SATLT LOOPS ARE SHOWING ELEVATED
CONVECTION BLOSSOMING ACROSS EAST CENTRAL IA JUST TO THE W OF THE
QUAD CITIES.  YESTERDAY/S ETA DID A GOOD JOB PICKING UP ON THIS.
THIS SAME MODEL ALSO BROUGHT THE SAME AREA OF TSTMS INTO THE SRN
PORTION OF THE CHI AREA TODAY.  HOWEVER...LOOKING AGAIN AT SATELLITE
TRENDS IT APPEARS THAT DEVELOPMENT OF THIS CONVECTION WILL BE
SOMEWHAT SOUTH OF EAST AS LINE OF ACCAS APPEARS TO BE DVLPG SEWD
FROM CURRENT ACTIVITY...TO SRN FRINGE COUNTIES OF THE CHI FA.  WITH
THIS IN MIND...WILL GO LIKELY POPS FAR SRN COUNTIES...TAPERING TO LO
CHC POPS IN RFD AND CHI.  WILL INCLUDE POPS FURTHER N MAINLY DUE TO
GUIDANCE FCSTS OF CAPES ABV 3000 J/KG IN AREA AS H7 TEMPS COOL TO
AROUND 9 OR 10 DEG.   AVN ALSO BRINGS A WAVE EWD ACROSS NRN IL THIS
AFTN AND ERLY TNGT ALONG DFUS SFC BOUNDARY THAT LIES ACROSS NRN IL.

GIVEN AMT OF INSTABILITY AND POSSIBLE /ALL BE IT WEAK/ TRIGGERS AM A
LITTLE UNCOMFORTABLE WITH DRY FCST.

AS WEAK WAVE SHIFTS OFF TO SE OF AREA LATE TNGT AND MON...INCRSG
NELY GRADIENT SHOULD STABILIZE THINGS.  THIS INCREASED AIR MOVEMENT
SHOULD ALSO START TO LOER DEW POINTS A BIT AFTER ANOTHER MUGGY DAY
TODAY.   ON TUESDAY...MDLS ARE SHOWING A REINFORCING COLD FRONT
MOVING THROUGH AND THIS SHOULD ACT TO DROP DEW POINTS MORE
NOTICEABLY WITH SOME DCRS IN TEMPS AS WELL.

WITH THIS SECOND FRONT PRESSING A LITTLE FURTHER TO S OF AREA SEE
LITTLE CHANCE FOR TSTM ACTIVITY INTO NRN IL/NWRN IN THRU EXTENDED PD
AS aSFC HI FCST TO BUILD SEWD AND SETTLE OVER LK MI BY LATE IN THE
WEEK.

.CHI...NONE.

MERZLOCK

ILZ003>006-008-010>014-019>023-032>033-039-INZ001>002-010>011-019-
091100-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE CHICAGO IL
NOON PM CDT/EST SUN JUL 8 2001

FOR NORTH CENTRAL AND NORTHEAST ILLINOIS AND NORTHWEST INDIANA.

A SEVERE THUNDERSTORM WATCH IS IN EFFECT FOR IROQUOIS...FORD AND
LIVINGSTON COUNTIES IN ILLINOIS UNTIL 6 PM CDT.

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING SOUTH OF A LINE FROM DIXON ILLINOIS TO DE MOTTE INDIANA.

THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS SOUTH OF A LINE
FROM MILFORD ILLINOIS TO STREATOR ILLINOIS.

A WARM FRONT LIES ACROSS CENTRAL ILLINOIS. ALONG THIS FRONT WARM AND
MOIST AIR IS POOLED RESULTING IN VERY UNSTABLE CONDITIONS.
THUNDERSTORMS WILL OCCUR THERE AND SOME OF THOSE THUNDERSTORMS COULD
BE SEVERE WITH HAIL...STRONG WINDS AND HEAVY RAINFALL.

WHW