Severe Thunderstorm Warning 244, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
140 PM CDT FRI AUG 1 2003

MAIN FCST CONCERNS STEM AROUND PCPN CHANCES/TIMING FOR THE NEXT FEW
DAYS. SVR WEATHER THREAT LATE THIS AFTERNOON/EVENING ALSO SOMEWHAT
PROBLEMATIC. PATTERN EXPECTED TO REMAIN RATHER ACTIVE INTO EARLY
NEXT WEEK AS DEEP TROFF ALOFT IS SLOW TO MOVE EAST WHILE RIDGE OVER
THE WEST-ROCKY MTN STATES PRETTY MUCH STAYS IN PLACE. NUMEROUS-HARD
TO TIME SHORTWAVES IN THE FLOW...COUPLED WITH DAYTIME HEATING WILL
KEEP CHC POPS GOING FOR THE NEXT FEW DAYS AT LEAST. ALL IN ALL DID
NOT MAKE MANY CHANGES TO THE DATABASE.

FAIRLY UNSTABLE AIRMASS IN PLACE EARLY THIS AFTERNOON WITH WEAK COLD
FRONT ACROSS NORTHERN AND WESTERM IL EXTENDING SW INTO MO. SFC
DEWPOINTS CREEPING UP INTO THE LOW 70S. CONVECTION SO FAR HAS BEEN
ALONG A RFD-ORD LINE WHERE THE CAP IS THE WEAKEST. 18Z ILX SOUNDING
SHOWING WEAK WIND FIELDS BUT VERY UNSTABLE AIRMASS IN PLACE
OTHERWISE...ALONG WITH STEEP LAPSE RATE. WITH PEAK HEATING
APPROACHING ALONG WITH SLOW MOVING FRONT EXPECT TSRA...SOME SVR TO
START FIRING WITHIN THE NEXT COUPLE HOURS. ACTIVITY TO WEAKEN
SOMEWHAT INTO THE EVENING HOURS AND SLOWLY MOVE E-SE. BEST CHC POPS
SHOULD BE ACROSS THE FAR SOUTH TONIGHT. HEAVY RAIN POSSIBLE FAR
SOUTH ALSO...MAINLY LATE AS MODELS INDICATE A LOW/MCS TYPE EVENT
TONIGHT OVER MO MOVE EAST INTO S IL. MODELS ALL SHOWING DIFFERENT
PICTURES TONIGHT AS FAR AS AREAL AND TEMPORAL COVERAGE OF PCPN.

KEPT CHC POPS GOING IN THE DATABASE FOR SAT WITH BEST CHCS STILL
APPEARING TO BE S-SE ZONES ALONG/NEAR WEAKENING FRONT. TEMPS LOW TO
MID 80S THE NEXT 2-3 DAYS. KEPT CHC POPS GOING SUNDAY IN CYCLONIC
FLOW ALOFT/SHORTWAVES AND HEATING. ALSO KEPT CHC POPS GOING RIGHT ON
INTO MONDAY AS MODELS DEVELOP WARM FRONT OVER THE AREA.

GFS TRIES TO BRING MCS TYPE ACTIVITY ACROSS MO AND S IL LATE TUE
NIGHT/WED. KEPT THE ZONES DRY FOR NOW AS IT LOOKS LIKE THIS WILL
STAY SOUTH OF THE AREA BUT WILL HAVE TO MONITOR SUBSEQUENT MODEL
RUNS FOR THIS FEATURE. LIKEWISE...GFS BRINGS QPF INTO THE AREA AGAIN
ON THURS BUT THIS LOOKS FISHY (AND TO DRY) SO HOLDING OFF ON
INTRODUCING ANY POPS ATTM. KEPT FRIDAY DRY ALSO. TEMPS THRU THE
PERIOD BASICALLY MID 60S LOWS TO MID 80S HIGHS.

MOS TEMPS SIMILAR...MOS POPS ALL HAVE A DIFFERENT FLAVOR...BASICALLY
USING A BLEND FOR NOW.

ISC GRIDS LOOK CLOSE. FURTHER COORDINATION WELCOME. ALL GRIDS SENT
EARLIER.

.ILX...NONE.

HALL

ILZ027>031-036>038-040>057-061>063-066>068-071>073-021100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LINCOLN IL
1050 AM CDT FRI AUG 1 2003

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

.DAY ONE...TODAY AND TONIGHT
THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS ACROSS CENTRAL AND
SOUTHEAST ILLINOIS THIS AFTERNOON INTO THE OVERNIGHT HOURS. LARGE
HAIL AND DAMAGING DOWNBURST WINDS WILL BE THE MAIN SEVERE WEATHER
THREAT. A STRONG UPPER LEVEL DISTURBANCE COMBINED WITH A FRONTAL
BOUNDARY MOVING ACROSS ILLINOIS THIS AFTERNOON AND TONIGHT WILL
IGNITE THUNDERSTORM ACTIVITY.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ON SATURDAY MAINLY
ALONG AND SOUTHEAST OF I-70. LARGE HAIL AND DAMAGING DOWNBURST WIND
GUSTS WILL AGAIN BE THE MAIN SEVERE WEATHER THREAT. THE STRONG UPPER
LEVEL DISTURBANCE OVER THE ARROWHEAD OF MINNESOTA WILL DIG SOUTHEAST
INTO THE GREAT LAKES THIS WEEKEND. THIS WILL KEEP A CHANCE OF MAINLY
AFTERNOON AND EVENING THUNDERSTORMS GOING THROUGH MONDAY.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION WILL BE NEEDED ACROSS CENTRAL AND SOUTHEAST
ILLINOIS THIS AFTERNOON AND TONIGHT.  THIS COULD BE A DANGEROUS
SITUATION

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

HTTP://WWW.CRH.NOAA.GOV/ILX. THIS ADDRESS IS ALL
IN LOWER CASE.

EH