Severe Thunderstorm Warning 163, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
850 PM CDT WED JUL 21 2004

.DISCUSSION...LOOKS LIKE THE BEST OPPORTUNITY FOR SURFACE-BASED
CONVECTIVE DEVELOPMENT IN THE NEXT HOUR OR TWO IS SOUTHEAST OF A
PARIS TO EFFINGHAM LINE. THIS PROSPECT IS BECOMING LESS AND LESS
WITH TIME AS INSTABILITY WEAKENS WITH DECREASING INSOLATION. FURTHER
WEST...OLD CONVECTIVELY INDUCED VORTMAX IS NOW CENTERED OVER THE
MIDDLE OF THE STATE. THIS AIRMASS...HOWEVER IS MORE CAPPED THAN
FURTHER EAST AND ANY DEVELOPMENT WITH THIS FEATURE SHOULD BE
ELEVATED. WITH THE UNSTABLE AIRMASS STILL IN PLACE ABOVE THE CAP...
CANNOT COMPLETELY DROP POPS FOR ANY ONE AREA. WILL CONTINUE WITH
CHANCE POPS OVERNIGHT. OTHER PORTIONS OF THE FORECAST IN GOOD SHAPE.

&&

.PREV DISCUSSION...
SHORT TERM...TONIGHT THROUGH FRIDAY...
BOUNDARY EXPECTED TO SLOWLY SAG SOUTH INTO CWA OVER THE NEXT 24
HOURS ALLOWING AXIS OF CONVECTION TO BEGIN TO IMPACT AREA. FORECAST
AREA WELL INTO WARM SECTOR THIS AFTERNOON WITH DEW POINTS WELL INTO
THE 70S. BLOW-OFF CLOUDS FROM IOWA/NORTHERN ILLINOIS CONVECTION HAVE
HAMPERED HEATING A BIT IN THE NORTH BUT STILL LOOKING AT CAPES AS
HIGH AS 5500 J/KG. HOWEVER...ALSO HAVE NICE CAP STILL IN PLACE.
PREFRONTAL SURFACE TROUGH IS EVIDENT IN A NORTHEAST-SOUTHWEST
ORIENTATION FROM PONTIAC TO NEAR TAYLORVILLE. LAPS INDICATES BEST
INSTABILITY AND WEAKEST CAP ALONG THIS BOUNDARY AND FEEL THAT THAT
AREA ALONG BOUNDARY MAY BE ABLE TO FIRE NEXT FEW HOURS.
OTHERWISE...FORECAST AREA MAY HAVE TO WAIT FOR BETTER ORGANIZED
SYSTEM TO ENTER THE REGION FROM NORTHERN MISSOURI LATER THIS
AFTERNOON INTO THIS EVENING.

CONVECTIVE AXIS SHOULD SET UP ACROSS AREA ON THURSDAY BRINGING
ANOTHER SHOT AT STORMS. ALTHOUGH INSTABILITY SHOULD BE LESS...BEST
FLOW AT MIDDLE LEVELS SHOULD ALSO BE IN PLACE. A SERIES OF
DISTURBANCES SHOULD LEAD TO A GOOD CHANCE OF STORMS.  AS BOUNDARY
SHIFTS SOUTH ON FRIDAY POPS SHOULD END FROM THE NORTH. WILL KEEP
CHANCE IN ALL AREAS EARLY FRIDAY PER 12Z ETA.

FOLLOWED CLOSELY MAV TEMP GUIDANCE. MET SEEMS TOO COOL WITH
FORECASTS OF ONLY UPPER 60S AT SPRINGFIELD FRIDAY.

LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...
SURFACE RIDGE BUILDS INTO REGION FRIDAY NIGHT BRINGING ANOTHER COOL
AND DRY WEEKEND TO FORECAST AREA. 00Z GFS ENSEMBLES AND MEAN SUGGEST
GENERALLY DRY CONDITIONS SHOULD CONTINUE THROUGH THE REMAINDER OF
PACKAGE.  WITH LACK OF SURFACE FOCUS AND GULF MOISTURE CUT OFF WILL
GO DRY.

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
IL...NONE.

&&

04/BARKER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LINCOLN IL
1042 AM CDT WED JUL 21 2004

ILZ027>031-036>038-221100-
FULTON-KNOX-MARSHALL-MCLEAN-PEORIA-STARK-TAZEWELL-WOODFORD-
INCLUDING THE CITIES OF...BLOOMINGTON...GALESBURG AND PEORIA
1043 AM CDT WED JUL 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL ILLINOIS.

.DAY ONE...THIS AFTERNOON AND TONIGHT...

A STATIONARY FRONT ACROSS NORTHERN ILLINOIS WILL INTERACT WITH A HOT
AND HUMID VERY UNSTABLE AIR MASS TO PRODUCE THUNDERSTORMS THIS
AFTERNOON AND INTO TONIGHT. THERE IS A MODERATE RISK THAT SOME OF
THESE STORMS COULD BECOME SEVERE ALONG AND NORTH OF A LEWISTOWN TO
PEKIN TO BLOOMINGTON LINE THIS AFTERNOON. THE PRIMARY THREAT WITH
THESE STORMS WILL BE BOW ECHOES WITH DAMAGING WIND GUSTS...ALONG WITH
LARGE HAIL AND HEAVY DOWNPOURS.

IN ADDITION TO THE STORMS...TEMPERATURES AROUND 90 DEGREES COMBINE
WITH DEWPOINTS IN THE 70S WILL CREATE HEAT INDICES OF 100 TO 105
DEGREES THIS AFTERNOON. CHILDREN...THE ELDERLY AND PEOPLE WITH
CHRONIC AILMENTS ARE USUALLY THE FIRST TO SUFFER FROM THE HEAT.
FRIENDS...RELATIVES OR NEIGHBORS SHOULD CHECK ON PEOPLE WHO MAY BE AT
RISK FROM THE HEAT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THE STATIONARY FRONT SLOWLY MOVE INTO THE AREA FOR THURSDAY AND
FRIDAY. THE FRONT WILL AGAIN INTERACT WITH THE HOT AND HUMID AIR
ALREADY IN PLACE AND PRODUCE THUNDERSTORMS ACROSS CENTRAL ILLINOIS ON
THURSDAY AND FRIDAY. THERE IS A SLIGHT RISK THAT SOME OF THESE STORMS
COULD BECOME SEVERE...WITH THE PRIMARY THREAT BEING LARGE HAIL AND
DAMAGING WINDS.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION WILL LIKELY BE REQUIRED THIS AFTERNOON AND MAY
STILL BE NEEDED TONIGHT.

ILZ040>057-061-221100-
CASS-CHAMPAIGN-CHRISTIAN-COLES-DE WITT-DOUGLAS-EDGAR-LOGAN-MACON-
MASON-MENARD-MORGAN-MOULTRIE-PIATT-SANGAMON-SCHUYLER-SCOTT-SHELBY-
VERMILION-
INCLUDING THE CITIES OF...CHAMPAIGN...DANVILLE...DECATUR...HAVANA...
JACKSONVILLE...LINCOLN...MATTOON...SHELBYVILLE...
SPRINGFIELD AND TAYLORVILLE
1043 AM CDT WED JUL 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL ILLINOIS.

.DAY ONE...TODAY AND TONIGHT...

A STATIONARY FRONT ACROSS NORTHERN ILLINOIS WILL INTERACT WITH HOT
AND HUMID VERY UNSTABLE AIR MASS TO PRODUCE THUNDERSTORMS THIS
AFTERNOON AND INTO TONIGHT. THERE IS A SLIGHT RISK THAT SOME OF THESE
STORMS COULD BECOME SEVERE ALONG AND NORTH OF A QUINCY TO SPRINGFIELD
TO TERRE HAUTE INDIANA LINE. THE PRIMARY THREAT WITH THESE STORMS
WILL BE LARGE HAIL...DAMAGING WINDS AND HEAVY DOWNPOURS.

IN ADDITION TO THE STORMS...TEMPERATURES IN THE LOWER 90S
WILL COMBINE WITH DEWPOINTS IN THE 70S TO CREATE HEAT INDEX VALUES IN
THE 100 TO 105 DEGREE RANGE THIS AFTERNOON. CHILDREN...THE ELDERLY
AND PEOPLE WITH CHRONIC AILMENTS ARE USUALLY THE FIRST TO SUFFER FROM
THE HEAT. FRIENDS...RELATIVES OR NEIGHBORS SHOULD CHECK ON PEOPLE WHO
MAY BE AT RISK FROM THE HEAT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THE STATIONARY FRONT SLOWLY MOVE INTO THE AREA FOR THURSDAY AND
FRIDAY. THE FRONT WILL AGAIN INTERACT WITH THE HOT AND HUMID AIR
ALREADY IN PLACE AND PRODUCE THUNDERSTORMS ACROSS CENTRAL ILLINOIS ON
THURSDAY AND FRIDAY. THERE IS A SLIGHT RISK THAT SOME OF THESE STORMS
COULD BECOME SEVERE...WITH THE PRIMARY THREAT BEING LARGE HAIL AND
DAMAGING WINDS.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS AFTERNOON AND TONIGHT.

ILZ062-063-066>068-071>073-221100-
CLARK-CLAY-CRAWFORD-CUMBERLAND-EFFINGHAM-JASPER-LAWRENCE-RICHLAND-
INCLUDING THE CITIES OF...EFFINGHAM...FLORA AND LAWRENCEVILLE
1043 AM CDT WED JUL 21 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST ILLINOIS.

.DAY ONE...TODAY AND TONIGHT...

ISOLATED THUNDERSTORMS WILL DEVELOP LATER THIS AFTERNOON AND INTO
THIS EVENING WITHIN A HOT AND HUMID AIR MASS. SOME OF THE STORMS
COULD CONTAIN HEAVY DOWNPOURS...SMALL HAIL AND GUSTY WINDS.

IN ADDITION TO THE STORMS...TEMPERATURES FROM 90 TO 95 DEGREES
COMBINED WITH DEWPOINTS IN THE 70S WILL CREATE HEAT INDEX VALUES IN
THE 100 TO 105 DEGREE RANGE THIS AFTERNOON. CHILDREN...THE ELDERLY
AND PEOPLE WITH CHRONIC AILMENTS ARE USUALLY THE FIRST TO SUFFER FROM
THE HEAT. FRIENDS...RELATIVES OR NEIGHBORS SHOULD CHECK ON PEOPLE WHO
MAY BE AT RISK FROM THE HEAT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY...

THE STATIONARY FRONT SLOWLY MOVE INTO THE AREA FOR THURSDAY AND
FRIDAY. THE FRONT WILL AGAIN INTERACT WITH THE HOT AND HUMID AIR
ALREADY IN PLACE AND PRODUCE THUNDERSTORMS ACROSS CENTRAL ILLINOIS ON
THURSDAY AND FRIDAY. THERE IS A SLIGHT RISK THAT SOME OF THESE STORMS
COULD BECOME SEVERE...WITH THE PRIMARY THREAT BEING LARGE HAIL AND
DAMAGING WINDS.

.SPOTTER ACTIVATION STATEMENT...

SPOTTER ACTIVATION IS NOT EXPECTED THROUGH TONIGHT.

&&
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.

HUETTL