Severe Thunderstorm Warning 289, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
221 AM CDT THU AUG 3 2006

.DISCUSSION...
PRIMARY CONCERNS WITH THIS PACKAGE WILL BE THE TIMING AND PLACEMENT
OF PRECIP/CONVECTION THROUGH DAY ONE.  FORECAST BECOMES QUIETER...
AND MILDER BEYOND THAT.

SHORT TERM...TODAY THROUGH SUNDAY...
FORWARD PROPAGATING MCS OVER EASTERN IA/WESTERN ILLINOIS IS
FOLLOWING CORFIDI VECTORS NICELY THIS MORNING.  THIS HAS BLOWN UP
OUT AHEAD OF A VIGOROUS SHORTWAVE WHICH IS MOVING ACROSS THE
MIDWEST.  MORE CONVECTION HAS FIRED UP JUST AHEAD OF THE SLOW MOVING
COLD FRONT ACROSS THE I-74 CORRIDOR.

MAIN PROBLEM IS THAT MODEL GUIDANCE HAS PRETTY MUCH DROPPED THE BALL
RIGHT FROM THE INITIALIZATION PERIOD WITH THIS MCS... BOTH NAM AND
GFS ALIKE.  RUC ANALYZED THE SITUATION WELL ENOUGH... BUT
MYSTERIOUSLY DROPPED OUR MCS SHARPLY SOUTHEASTWARD.

BASED ON TRENDS AND OBSERVATIONS... CURRENT MCS SHOULD CONTINUE
EASTWARD INTO THE FAR NW PORTION OF THE CWA EARLY THIS MORNING...
MAINLY BEFORE 12Z... AND BEGIN TO DECAY ONCE IT GETS EAST OF WHERE
THE LLJ IS MORE PRONOUNCED.  SOUTHERN EDGE OF THE MCS APPEARS TO BE
DECAYING THE MOST... AS IT IS FARTHER REMOVED FROM STRONGER LOW
LEVEL BAROCLINICITY.  BASICALLY... IT SHOULD HOLD TOGETHER BEST
NORTH OF WHERE CONVECTION HAS BEEN FIRING UP ALONG THE COLD FRONT.

CONVECTION SHOULD CONTINUE TO SHIFT SOUTHWARD THROUGH THE LATE
MORNING AND AFTERNOON HOURS... AHEAD OF THE COLD FRONT.  MAIN
CONCERNS WILL BE FOR HEAVY RAIN POTENTIAL BETWEEN THE I-74 AND I-72
CORRIDORS WHERE PRECIP MAY TEND TO TRAIN DUE TO PARALLEL NATURE OF
THE UPPER AND LOW LEVEL FLOW.  FFG VALUES ARE RATHER HIGH... BUT
WITH PWAT VALUES FORECAST TO RISE ABOVE 2 INCHES THIS AFTERNOON...
IT WILL NOT TAKE MUCH TRAINING TO CAUSE LOCALIZED PROBLEMS.  STILL
THINK THE THREAT WILL BE LOCALIZED ENOUGH... GIVEN THE ABOVE REASONS
PLUS LACK OF RECENT RAINS... THAT NO HEADLINES ARE NEEDED AT THIS
POINT.

SEVERE WEATHER THREAT WILL CONTINUE TO BE LIMITED THIS MORNING BY
NOCTURNAL INVERSION KEEPING STRONGER WINDS ALOFT... EXCEPT IN
ISOLATED AREAS... AND HIGH FREEZING LEVELS REDUCING THE THREAT FOR
LARGE HAIL.  BEST BET FOR SVR WILL BE IN THE FAR SOUTHEAST THIS
AFTERNOON AND EARLY THIS EVENING... WHERE LACK OF CLOUD COVER WILL
PROMOTE RAPID SFC HEATING THIS AFTERNOON... WITH TEMPS APPROACHING
THE LOWER 90S.  THIS WILL ALLOW FOR PLENTY OF INSTABILITY...
ALLOWING SFC BASED CONVECTION TO FIRE UP ALONG EITHER THE COLD FRONT
ITSELF... OR ANY NUMBER OF LEFTOVER OUTFLOW BOUNDARIES PRECEDING IT.

FRONT IS STILL EXPECTED TO LINGER IN THE FAR SOUTHEAST THROUGH
TOMORROW AFTERNOON... WARRANTING CHANCE POPS SOUTH OF I-70 THROUGH
TOMORROW.

LONG TERM...MONDAY THROUGH WEDNESDAY...
GUIDANCE STILL IN VERY GOOD AGREEMENT WITH THE MEAN UPPER LEVEL
PATTERN THROUGH THE PERIOD.  THIS SUGGESTS EVENTUAL RETROGRESSION OF
SUBTROPICAL HIGH BACK OVER THE PLAINS... WHERE IT BELONGS... AND THE
SETTING UP OF A NORTHWEST FLOW PATTERN OVER THE MIDWEST BY EARLY
NEXT WEEK.  NEXT SHORTWAVE LOOKS TO MOVE ACROSS THE NORTHERN GREAT
LAKES IN THE MON-TUE TIMEFRAME... AND THE GFS AND ENSEMBLES CONTINUE
TO BE RATHER WOUND UP WITH THIS SYSTEM.  STILL... THIS SUPPORTS
CHANCE POPS MONDAY AND TUESDAY AFTERNOON... WITH THE POSSIBILITY OF
A WET PERIOD SETTING UP TOWARDS THE BEGINNING AND MIDDLE OF NEXT
WEEK WITH A STATIONARY FRONT SETUP ACROSS THE AREA... AND NORTHWEST
FLOW ALOFT.

&&

ILX WATCHES/WARNINGS/ADVISORIES...NONE.

&&

HARDIMAN

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE LINCOLN IL
1115 AM CDT WED AUG 2 2006

ILZ027>031-036>038-040>043-047>051-031100-
KNOX-STARK-PEORIA-MARSHALL-WOODFORD-FULTON-TAZEWELL-MCLEAN-
SCHUYLER-MASON-LOGAN-DE WITT-CASS-MENARD-SCOTT-MORGAN-SANGAMON-
1115 AM CDT WED AUG 2 2006

THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL
ILLINOIS.

.DAY ONE...THIS AFTERNOON AND TONIGHT

DANGEROUSLY HOT AND HUMID AIR WILL CONTINUE OVER THE AREA TODAY.
TEMPERATURES IN THE UPPER 90S WILL COMBINE WITH DEWPOINTS IN THE
70S TO PRODUCE HEAT INDEX VALUES OF 105 TO 110 DEGREES THIS
AFTERNOON INTO EARLY THIS EVENING.

A SLOW MOVING FRONT WILL ALSO MOVE IN AND INTERACT WITH THE
TROPICAL AIR MASS OVER THE AREA. THIS COMBINATION WILL PRODUCE
THUNDERSTORMS ACROSS PARTS OF CENTRAL ILLINOIS TONIGHT. THERE IS A
SLIGHT RISK THAT SOME OF THESE STORMS COULD BECOME SEVERE...WITH
DAMAGING WINDS AND LARGE HAIL BE THE PRIMARY SEVERE WEATHER THREAT.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE SLOW MOVING FRONT WILL REMAIN ACROSS PARTS OF CENTRAL ILLINOIS
ON THURSDAY...BRINGING THE CONTINUED THREAT OF THUNDERSTORMS TO
THE AREA THROUGH THURSDAY NIGHT. THERE IS A SLIGHT RISK THAT SOME OF
THESE STORMS COULD BECOME SEVERE.

ANOTHER FRONT WILL MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER
CHANCE OF THUNDERSTORMS TO CENTRAL ILLINOIS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED THIS EVENING AND INTO TONIGHT.

ILZ044>046-052>057-061>063-066>068-071>073-031100-
PIATT-CHAMPAIGN-VERMILION-CHRISTIAN-MACON-MOULTRIE-DOUGLAS-COLES-
EDGAR-SHELBY-CUMBERLAND-CLARK-EFFINGHAM-JASPER-CRAWFORD-CLAY-
RICHLAND-LAWRENCE-
1115 AM CDT WED AUG 2 2006

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

.DAY ONE...THIS AFTERNOON AND TONIGHT

DANGEROUSLY HOT AND HUMID AIR WILL CONTINUE OVER THE AREA TODAY.
TEMPERATURES IN THE UPPER 90S WILL COMBINE WITH DEWPOINTS IN THE
70S TO PRODUCE HEAT INDEX VALUES 105 TO 110 DEGREES THIS AFTERNOON
INTO EARLY THIS EVENING.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

A SLOW MOVING FRONT WILL MOVE INTO PARTS OF CENTRAL AND SOUTHEAST
ILLINOIS ON THURSDAY. THIS FRONT WILL INTERACT WITH THE TROPICAL AIR
MASS IN PLACE OVER THE AREA...BRINGING THE THREAT OF THUNDERSTORMS
THROUGH THURSDAY NIGHT. THERE IS A SLIGHT RISK THAT SOME OF THESE
STORMS COULD BECOME SEVERE.

ANOTHER FRONT WILL MOVE INTO THE AREA ON MONDAY...BRINGING ANOTHER
CHANCE OF THUNDERSTORMS TO CENTRAL AND SOUTHEAST ILLINOIS.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT ANTICIPATED THROUGH TONIGHT.

KMH/SLOVE/AUTEN

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LINCOLN IL
901 PM CDT WED AUG 02 2006

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0856 PM     TSTM WND GST     2 S PHILADELPHIA        39.89N 90.12W
08/02/2006  E60 MPH          CASS               IL   CO-OP OBSERVER

            SWOP REPORT.

&&

GEELHART