Flash Flood Warning 11, NWS Lincoln, IL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
245 PM CDT THU JUL 1 1999

FCST CHALLENGES THIS PD WL BE TIMING OF PRECIP ACRS CWFA AND HOW
QUICKLY WMFNT SHIFTS NORTH OF STATE ON FRI.

18Z SFC ANALYSIS INDICATED WEAK STATIONARY BNDRY ACRS CNTRL IL WITH
TROF/WND SHIFT LINE ACRS IA. WATER VAPOR LOOP SUGGESTING ETA MODEL
DID THE BEST WITH THE MCV ACRS SRN MO AND THE VORT TROF DEPICTED ACRS
CNTRL IA EARLY THIS AFTERNOON. BEST LOW LVL CONVERGENCE AND THETA-E
ADV FCST TO REMAIN OVR EXTREME SRN IL THIS EVE AND TNT AND THUS THE
HIGHEST POPS WL REMAIN ACRS THAT AREA AS WELL. FFA ISSUED EARLIER
TODAY FOR THE FAR SOUTHERN TWO TIERS OF COUNTIES STILL LOOKS GOOD FOR
THE EVENING HOURS AS TSRA CONTINUES TO DVLP ALNG INSTABILITY AXIS
LOCATED FM WRN TN NWD INTO SRN IL. THE REAL FCST PROBLEM WL BE PRECIP
CHANCES NORTH OF DECAYING MCC AS WEAK CNTRL IA VORT SHIFTS THRU NRN
IL DURING THE EVENING. ETA MODEL INDICATING H5 COLD POOL ASSOCIATED
WITH THE NRN STREAM VORT SHOULD PUSH ACRS THE NRN HALF OF OUR CWFA
DURING THE EVENING WARRANTING LOW POPS. LATER ON TONIGHT...BEST LOW
LVL FORCING SHIFTS BACK INTO THE CNTRL PLAINS AS THETA-E RIDGE IS
ALINGNED FRM KS NWD TO THE DAKOTAS. FAIRLY IMPRESSIVE LOW LVL
CONVERGENCE AND UPPER LVL DIVERGENCE COUPLET ACRS WRN IA SUGGESTING
NEXT CONVECTIVE SYSTEM TO FORM WELL WEST OF AREA LATE TNT..

NEXT PROBLEM WL BE EVENTUAL NWD PROGRESSION OF WMFNT WHICH MODELS
HAVE BEEN HAVING A TOUGH TIME WITH. ETA MODEL SUGGESTING BOUNDARY
WILL SHIFT SLOWLY NORTH WITH TIME ON FRI PASSING NORTH OF FCST
AREA FRI NIGHT AS H7 TEMPS SURPASS +10C BY EVENING. WITH BOUNDARY
LOCATED ACRS FCST AREA ON FRI AND CAPES SKY ROCKETING TO AROUND
4000 J/KG...WL KEEP POPS GOING DURING THE DAY AND INTO THE EVENING
HOURS NORTH. THEN THE HEAT BUILDS INTO THE MIDWEST FOR THE HOLIDAY
WEEKEND WITH MCC ACTIVITY SHIFTING INTO THE NRN PLAINS AND GREAT
LAKES REGION. ALREADY ADDRESSED THE POTENTIAL PROBLEMS THAT MAY BE
CAUSED BY THIS WEEKENDS HIGH HEAT AND HUMIDITY WITH AN SPS.

FAN NUMBERS SEEM TO BE A BIT ON THE COOL SIDE THRU THE FIRST 24 HRS
AND MAY TEND TO FOLLOW THE FWC GUID THRU FRI. WITH WARM FRONT WELL TO
OUR NORTH BY SAT AND DECENT SWLY FLOW...NO REASON TO KEEP HIGHS DOWN
AS DEPICTED ON THE FWC GUID FOR SATURDAY. WL TEND TO FAVOR THE WARMER
FAN NUMBERS IN THE OUT PDS.

PRELIMINARY TEMPS/POPS

SPI BB 068/088 073/093 76 44432
PIA BB 066/088 072/092 75 44332
DEC BB 065/087 073/093 76 44732
CMI BB 066/087 073/093 75 44432
MTO BB 068/088 073/093 75 44532
LWV BB 069/089 075/094 76 44732

SMITH

EFFECTIVE AT 4 AM CDT JUL 7 1999...THIS PRODUCT WILL BE ISSUED UNDER
THE FOLLOWING HEADERS:

NOAA WEATHER WIRE:    CHIAFDILX
FAMILY OF SERVICES:   FXUS63 KILX (NO CHANGE FROM CURRENT)

ILZ027>031-036>038-040>057-061>063-066>068-071>073-021200-

SEVERE WEATHER OUTLOOK FOR CENTRAL AND SOUTHEASTERN ILLINOIS
NATIONAL WEATHER SERVICE LINCOLN IL
1105 AM CDT THU JUL 1 1999

THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS EASTERN AND
SOUTHEAST ILLINOIS THIS AFTERNOON AND TONIGHT.  THE SEVERE WEATHER
THREAT IS LOCATED MAINLY EAST OF A LINE FROM BLOOMINGTON TO DECATUR
TO MATTOON.

AN UPPER LEVEL DISTURBANCE OVER SOUTH DAKOTA WILL TRACK
EAST SOUTHEAST INTO CENTRAL AND NORTHERN ILLINOIS THIS EVENING. IN
ADDITION...A WARM FRONT IS GOING TO CONTINUE ITS GRADUAL JOURNEY
NORTH ACROSS CENTRAL AND NORTHERN ILLINOIS THROUGH TONIGHT FEEDING
WARM...MOIST AND UNSTABLE AIR INTO THE AREA.

WIDESPREAD SHOWERS AND THUNDERSTORMS WILL DEVELOP AGAIN BY MID
AFTERNOON AND CONTINUE THROUGH THIS EVENING.   THE MAIN SEVERE
WEATHER THREAT WILL BE DAMAGING WINDS WITH ISOLATED LARGE HAIL AND
SHORT LIVED TORNADOES POSSIBLE. IN ADDITION.V..EXPECT LOCALLY HEAVY
RAINS OF 1 TO 2 INCHES IN AN HOUR OR TWO CAUSING LOW LYING FLOODING
IN POOR DRAINAGE AREAS.

SPOTTER ACTIVATION MAY BE NEEDED LATER THIS AFTERNOON AND EVENING.

KETCHAM

ILZ027>031-036>038-040>057-061>063-066>068-071>073-020900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
211 PM CDT THU JUL 1 1999

...OPPRESSIVE HEAT AND HUMIDITY HEADED FOR CENTRAL ILLINOIS THIS
HOLIDAY WEEKEND...

THE RELIEF FROM THE HIGH HEAT AND HUMIDITY THE PAST SEVERAL DAYS
IS FORECAST TO END AS A WARM FRONT LIFTS NORTH OF THE REGION LATE
THIS WEEK. SOUTH OF THE FRONT...EXPECT DAYTIME TEMPERATURES TO SOAR
INTO THE 90S...AS OVERNIGHT LOWS FAIL TO FALL BELOW 70. THIS TREND
IS FORECAST TO CONTINUE INTO NEXT WEEK.

IN ADDITION...HUMIDITY LEVELS ARE EXPECTED TO MAKE IT FEEL EVEN
WARMER...WITH HEAT INDICES EXPECTED TO RISE AT TIMES TO NEAR 110
ON SUNDAY THE 4TH OF JULY AND INTO THE EARLY PART OF NEXT WEEK.

PROLONGED EXPOSURE TO THIS LEVEL OF HEAT AND HUMIDITY COMBINED WITH
PHYSICAL ACTIVITY CAN CAUSE HEAT EXHAUSTION AND HEAT STROKE. BE
SURE TO DRINK PLENTY OF LIQUIDS...WEAR LIGHTWEIGHT...LIGHT-COLORED
CLOTHING AND BE SURE TO TAKE BREAKS FROM THE WEATHER BY RETREATING
INTO AN AIR-CONDITIONED LOCATION OR A SWIMMING POOL.

STAY TUNED FOR LATER STATEMENTS AND POSSIBLE ADVISORIES ON THIS
DEVELOPING HEAT EPISODE.

PLAHMER/SMITH

ILZ027>031-036>038-040>057-061>063-066>068-071>073-020900-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE LINCOLN IL
211 PM CDT THU JUL 1 1999

...OPPRESSIVE HEAT AND HUMIDITY HEADED FOR CENTRAL ILLINOIS THIS
HOLIDAY WEEKEND...

THE RELIEF FROM THE HIGH HEAT AND HUMIDITY THE PAST SEVERAL DAYS
IS FORECAST TO END AS A WARM FRONT LIFTS NORTH OF THE REGION LATE
THIS WEEK. SOUTH OF THE FRONT...EXPECT DAYTIME TEMPERATURES TO SOAR
INTO THE 90S...AS OVERNIGHT LOWS FAIL TO FALL BELOW 70. THIS TREND
IS FORECAST TO CONTINUE INTO NEXT WEEK.

IN ADDITION...HUMIDITY LEVELS ARE EXPECTED TO MAKE IT FEEL EVEN
WARMER...WITH HEAT INDICES EXPECTED TO RISE AT TIMES TO NEAR 110
ON SUNDAY THE 4TH OF JULY AND INTO THE EARLY PART OF NEXT WEEK.

PROLONGED EXPOSURE TO THIS LEVEL OF HEAT AND HUMIDITY COMBINED WITH
PHYSICAL ACTIVITY CAN CAUSE HEAT EXHAUSTION AND HEAT STROKE. BE
SURE TO DRINK PLENTY OF LIQUIDS...WEAR LIGHTWEIGHT...LIGHT-COLORED
CLOTHING AND BE SURE TO TAKE BREAKS FROM THE WEATHER BY RETREATING
INTO AN AIR-CONDITIONED LOCATION OR A SWIMMING POOL.

STAY TUNED FOR LATER STATEMENTS AND POSSIBLE ADVISORIES ON THIS
DEVELOPING HEAT EPISODE.

PLAHMER/SMITH