Hail in Illinois, April 30, 2003

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
245 AM CDT WED APR 30 2003

MODELS SIMILAR IN LIFTING A WARM FRONT NORTH ACROSS CENTRAL IL
TODAY...GETTING NORTH OF CWA DURING EARLY AFTERNOON. BUT MODEL QPF
AND SHORT WAVES EJECTING INTO THE GREAT LAKES FROM THE LONG WAVE
TROF ACROSS THE ROCKIES DIFFERS. GFS SUFFERING SOME CONVECTIVE
FEEDBACK SO PUTTING MORE WEIGHT ON THE ETA MODEL THIS RUN. FORECAST
CHALLENGE IS ADDRESSING CONVECTION CHANCES AND POSSIBLE SEVERE
WEATHER INTO THU NIGHT.

ONE MCS ACROSS NEBRASKA AND A SECOND ONE ACROSS IA DEVELOPING EAST
INTO NORTHERN IL. RADAR MOSAIC HAS SCATTERED CONVECTION DEVELOPING
ACROSS NORTHERN ILX CWA FROM PEORIA NORTH AND MORE WIDESPREAD
CONVECTION ALONG AND NORTH OF I-80. A LONE THUNDERSTORM MOVING NE
INTO SCOTT COUNTY TOWARD WINCHESTER. 07Z SURFACE ANALYSIS HAS 999 MB
LOW IN FAR SE CO WITH A WARM FRONT ARCHING ACROSS NORTHERN KS/MO AND
SOUTHERN IL NEAR I-70. 850 MB WARM FRONT FURTHER NORTH ACROSS
CENTRAL NE/IA INTO NORTHERN IL WHERE MOST CONVECTION FOCUSED ALONG
AND NORTH OF THIS BOUNDARY WITH INTERSECTING 40 TO 60 KNOT SOUTHERLY
850 MB JET.

WILL CONTINUE LIKELY CHANCE OF SHOWERS AND THUNDERSTORMS TODAY AND
TONIGHT FROM PEORIA NORTH WITH GOOD CHANCE CENTRAL AND PROB40 SE.
SPC DAY1 OUTLOOK HAS SLIGHT RISK NORTH OF I-70 TODAY AND TONIGHT
WITH MODERATE RISK NW OF THE IL RIVER. VERY UNSTABLE WITH ETA LIFTED
INDICES FROM MINUS 4 TO 8 WHILE CAPES 2000 TO 3000 J/KG. BEST CHANCE
OF SEVERE TO BE ALONG WARM FRONT OVER NW IL THIS AFTERNOON AND
EVENING. SHEAR STRONG ENOUGH TO SUPPORT SUPERCELLS. NEW GUIDANCE HAS
WARMED ABOUT 5 DEGREES TODAY INTO THE UPPER 70S NORTH AND LOWER 80S
CENTRAL AND SOUTH AND WILL FOLLOW.

LOW PRESSURE EJECTING INTO THE SOUTHERN GREAT LAKES THU BRINGS COLD
FRONT SLOWLY SE THRU CENTRAL IL THU AFTERNOON AND EVENING. SPC DAY2
OUTLOOK HAS SLIGHT RISK SE OF THE IL RIVER THU AND THU NIGHT. AGAIN
VERY UNSTABLE WITH LIFTED INDICES AGAIN MINUS 4 TO 8C WITH CAPES OF
1500 TO 3000 J/KG SE OF THE IL RIVER. SUPERCELLS AGAIN POSSIBLE
ESPECIALLY EASTERN IL WITH STRONG SHEAR. SPC THINKING MODERATE RISK
MAY BE NEEDED IN PART OF THE MID MISSISSIPPI AND OHIO VALLEYS. WILL
HAVE LIKELY CHANCE OF CONVECTION ACROSS ILX CWA THU AND INTO EASTERN
IL THU EVENING WITH CHANCE WEST THU NIGHT. FOLLOWED MILDER FWC/MET
HIGHS THU RANGING FROM LOW 70S NW AND UPPER 70S TO NEAR 80 SE.

ETA AND GFS SHOWING A SHORT WAVE AND UPPER LEVEL TROF MOVING EAST
ACROSS NORTHERN IL FRI AND MODELS SLOWER WITH BRINGING IN DRIER AIR.
SO WILL HAVE CHANCE OF SHOWERS DURING THE DAY FRI. THEN DRY FRI
NIGHT AND SAT AS HIGH PRESSURE BUILDS IN. EXTENDED FORECAST LOOKS
GOOD WITH NEXT CHANCE OF CONVECTION BY SUNDAY AFTERNOON AND MONDAY
AS ANOTHER STRONG STORM SYSTEM EJECTS OUT OF CO INTO THE GREAT LAKES.

.ILX...NONE.

HUETTL

ILZ027>031-036>038-040>057-061>063-066>068-071>073-301100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LINCOLN IL
1136 AM CDT TUE APR 29 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL AND
SOUTHEAST ILLINOIS.

.DAY ONE...TODAY AND TONIGHT

THERE WILL BE A RISK OF SEVERE THUNDERSTORMS LATE TONIGHT MAINLY TO
THE WEST OF I-55. LARGE HAIL AND VERY HEAVY RAINFALL WILL BE THE
PRIMARY THREATS. IN THE MEANTIME...OTHER THUNDERSTORMS WILL BE
POSSIBLE DURING THE DAYLIGHT HOURS THIS AFTERNOON...HOWEVER NO
ORGANIZED SEVERE WEATHER IS ANTICIPATED WITH THIS ACTIVITY.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

THE THREAT FOR SEVERE WEATHER WILL SHIFT NORTH ON WEDNESDAY...AND
WILL BE PRIMARILY FROM PEORIA NORTHWARD DURING THE AFTERNOON AND
EVENING HOURS. LARGE HAIL AND DAMAGING WINDS WILL BE POSSIBLE NEAR A
WARM FRONT THAT WILL BE DRAPED OVER NORTHERN ILLINOIS.

MUCH OF CENTRAL ILLINOIS WILL BE UNDER THE GUN FOR SEVERE WEATHER ON
THURSDAY AS A COLD FRONT MOVES EAST ACROSS ILLINOIS.

YET ANOTHER STORM SYSTEM WILL AFFECT THE AREA LATE SUNDAY INTO
MONDAY...BRINGING ANOTHER THREAT OF THUNDERSTORMS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED LATE TONIGHT INTO WEDNESDAY AND
THURSDAY.

&&
THIS PRODUCT...ALONG WITH OTHER WEATHER...HYDROLOGIC
AND CLIMATE INFORMATION...IS AVAILABLE ON THE WEB AT:

HTTP://WWW.CRH.NOAA.GOV/ILX (ALL IN LOWER CASE)

BYRD