Hail in Illinois, May 19, 2005

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
645 AM CDT THU MAY 19 2005

.DISCUSSION...

SHOWERS AND TS WIDESPREAD ACROSS THE AREA THIS MORNING AS UPPER LOW
MOVES SE ACROSS THE MIDWEST. DEVELOPMENT CONTINUES ACROSS NW IL.
THIS ACTIVITY PUSHES EAST THIS MORNING. EXPECT WESTERN AND SOUTHERN
SECTIONS OF THE CWA TO CLEAR OUT SOME TO ALLOW SUNSHINE AND HEATING
ALLOWING FOR GREAT INSTABILITY LATER THIS MORNING AND EARLY THIS
AFTERNOON. MOST OF THE AREA...SOUTH OF I-90 OUTLOOKED FOR SLGT RISK
OF SVR LATER TODAY WITH THE SOUTHERN CWA APPEARING MOST AT RISK FOR
ANY SVR. THIS ACTIVITY PUSHES SOUTH THIS EVENING AND WILL INCLUDE
MENTION OF TS SOUTH THIS EVENING...JUST SHOWERS NORTH AND PRECIP
CLEARS ALL BUT THE FAR SOUTHEAST CWA BY 12Z FRI. TEMPS RATHER TRICKY
TODAY WITH THE NORTH POSSIBLY REMAINING CLOUDY WITH WINDS TURNING
OFF THE LAKE BY AFTERNOON. BUT ANY SUN SHOULD ALLOW AT LEAST MID 70S
SOUTH. TEMPS TONIGHT LIKELY ON THE WARMER SIDE OF GUIDANCE WITH
EXPECTED SLOW CLEARING AND POSSIBLY LOW CLOUDS OFF LK MI. SKIES
BEGIN TO CLEAR FRI WITH FRI NIGHT AND SAT ON TRACK TO BE DRY. STILL
COOLER ALONG THE LAKE FRI AND SAT AFTERNOONS.

CHANGES TO THE FORECAST ARISE SAT NIGHT INTO SUN. GFS PICKED UP ON
FASTER FROPA 24 HRS AGO BUT STILL HAD FROPA SUN AFTERNOON. NAM/GFS
IN GOOD AGREEMENT THIS MORNING WITH SFC LOW DIVING SOUTH FROM
ONTARIO SAT NIGHT INTO SUN WITH ASSOCIATED FRONT PUSHING THRU SUNDAY
MORNING. FIRST IMPACT IS THIS WILL AFFECT TEMPS SUN/MON. BUT ALSO
HAVE INTRODUCED CHANCE POPS LATE SAT NIGHT INTO SUNDAY. MOISTURE
STILL RATHER LIMITED BUT BETTER THAN RUNS 24 HRS AGO. THIS SYSTEM
EXITS EAST SUNDAY NIGHT. MON/TUES LOOKING DRY BUT A LITTLE COOLER.
CHANCE OF TS AGAIN TUES NIGHT INTO WED AND NO CHANGES HERE.

&&

.AVIATION...
THE FIRST WAVE OF THUNDERSTORMS HAS MOVED THROUGH NORTHEAST ILLINOIS
AND THE TAFS FORECAST AREA. THE SHORT WAVE SEEN ON THE WATER VAPOR
IMAGERY WAS IN NORTHWEST WISCONSIN AT 1131 UTC. THE MODELS HAVE THIS
SPEEDING INTO ILLINOIS BY 06 UTC. BY 21 UTC THERE IS FORECAST ENOUGH
POSITIVE VORTICITY ADVECTION THAT SHOWERS WILL REAPPEAR THIS
AFTERNOON. WILL ADD SHOWERS TO THE FORECAST FROM 1800 UTC TO 2300
UTC. NOT SURE OF THE TIMING OF THUNDERSTORMS THIS AFTERNOON. THE
ACARS SOUNDING HAS A SMALL INVERSION OVER ORD AT 920 UTC. THE CLOUDS
MAY REMAIN OVER THE AREA AND THERE IS SOME FOG IN PARTS OF THE
FORECAST AREA. AFTER THE FRONT PASSES AS THE LOW MOVES SOUTH TONIGHT
EXPECT HIGHER CEILINGS AND IMPROVED VISIBILITY.

&&

.LOT...WATCHES/WARNINGS/ADVISORIES...
.IL...NONE.
.IN...NONE.
.LK MI...NONE.

HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE CHICAGO/ROMEOVILLE IL
1015 AM CDT THU MAY 19 2005

ILZ003>006-008-010>014-019>022-023-032-033-039-INZ001-002-010-011-019
-201100-
WINNEBAGO-BOONE-MCHENRY-LAKE IL-OGLE-LEE-DE KALB-KANE-DU PAGE-COOK-
LA SALLE-KENDALL-GRUNDY-WILL-KANKAKEE-LIVINGSTON-IROQUOIS-FORD-
LAKE IN-PORTER-NEWTON-JASPER-BENTON-
1015 AM CDT THU MAY 19 2005

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR NORTH CENTRAL
AND NORTHEAST ILLINOIS...AND NORTHWEST INDIANA.

.DAY ONE... THIS AFTERNOON AND TONIGHT

THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND CONTINUE
INTO THE EVENING HOURS. THERE IS A SLIGHT RISK SOME OF THESE
THUNDERSTORMS MAY BECOME SEVERE...MAINLY ALONG AND SOUTH OF
INTERSTATE 80. THE MAIN THREATS WILL BE DAMAGING WIND GUSTS AND
LARGE HAIL.

.DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY

THERE IS A CHANCE OF THUNDERSTORMS SATURDAY NIGHT AND SUNDAY...AND
AGAIN TUESDAY NIGHT AND WEDNESDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTERS MAY BE NEEDED TODAY AND THIS EVENING.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)

LMZ740>746-766-201100-
WINTHROP HARBOR IL TO NEW BUFFALO MI-
LAKE MICHIGAN-
1015 AM CDT THU MAY 19 2005

THIS PORTION OF THE HAZARDOUS WEATHER OUTLOOK IS FOR THE ILLINOIS
AND INDIANA WATERS OF LAKE MICHIGAN.

.DAY ONE... THIS AFTERNOON AND TONIGHT

A SMALL CRAFT ADVISORY WILL BE IN EFFECT THIS AFTERNOON FOR THE
ILLINOIS NEARSHORE WATERS...MAINLY FOR HIGH WAVES TO 5 FEET.

THUNDERSTORMS ARE EXPECTED TO REDEVELOP THIS AFTERNOON AND CONTINUE
INTO THE EVENING HOURS. THESE STORMS ARE NOT EXPECTED TO BECOME
SEVERE OVER LAKE MICHIGAN.

.DAYS TWO THROUGH SEVEN... FRIDAY THROUGH WEDNESDAY

THERE IS A CHANCE OF THUNDERSTORMS SATURDAY NIGHT AND SUNDAY...AND
AGAIN TUESDAY NIGHT AND WEDNESDAY.

&&

COMPLETE FORECAST INFORMATION IS AVAILABLE ON THE
NWS CHICAGO WEBPAGE: WEATHER.GOV/CHICAGO (LOWER CASE)