023
FXUS63 KILX 051054
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
554 AM CDT SAT SEP 5 2026
KEY MESSAGES
- DANGEROUS HEAT TODAY: HEAT INDEX VALUES WILL REACH TO AROUND
105 DEGREES AGAIN TODAY. THE EXTREME HEAT WARNING COVERS ALL
OF CENTRAL ILLINOIS.
- BRIEF WEEKEND RELIEF: A COLD FRONT PUSHING SOUTH WILL BRING
SLIGHTLY LESS HOT AND HUMID CONDITIONS TO NORTHERN AREAS
SUNDAY AND MONDAY, DROPPING HIGHS INTO THE MID-TO-UPPER 80S.
SOUTHERN AREAS WILL REMAIN WARMER, AROUND 90.
- HEAT RETURNS NEXT WEEK: THE BRIEF BREAK IN OPPRESSIVE HEAT
WILL BE SHORT-LIVED. WIDESPREAD 90-DEGREE TEMPERATURES ARE
FORECAST TO RETURN TUESDAY AND WEDNESDAY. HOWEVER, DUE TO
LOWER DEWPOINTS IN THE 60S, TRIPLE-DIGIT HEAT INDEX VALUES
WILL ONLY BE FELT ON WEDNESDAY, AND SOUTH OF I-72/DANVILLE.
DISCUSSION
ISSUED AT 206 AM CDT SAT SEP 5 2026
CENTRAL ILLINOIS REMAINS POSITIONED ALONG THE EDGE OF A STRONG
UPPER-LEVEL RIDGE WITH A RING OF FIRE PATTERN RESULTING IN DAILY
CONVECTIVE CHANCES IN THE REGION, MAINLY TO OUR NORTH.
THE ADVERTISED BACKDOOR COLD FRONT WILL SAG ACROSS THE CWA
TODAY AND REACH SOUTHEAST ILLINOIS AROUND MAX HEATING. THE
AIRMASS WILL BE QUITE UNSTABLE, WITH MLCAPE OVER 4000 J/KG;
HOWEVER, SHEAR WILL BE VERY WEAK AT ONLY AROUND 15KTS. STILL,
SCATTERED SHOWERS AND THUNDERSTORMS ARE STILL POSSIBLE IN
SOUTHEAST IL THIS AFTERNOON. SINCE SHEAR IS WEAK ALONG THIS
FRONT, WILL KEEP POPS IN THE 20-30% RANGE, WHICH MATCHES WELL
WITH THE MARGINAL RISK ISSUED BY SPC. THESE SCATTERED STORMS
SHOULD PUSH EAST AND SOUTH QUICKLY OR DISSIPATE QUICKLY, LEAVING
TONIGHT DRY.
SINCE THE BACKDOOR FRONT IS SLOWLY SAGGING SOUTH TODAY, THE HIGH
HEAT AND HUMIDITY IS STILL EXPECTED TO CONTINUE INTO THE
AFTERNOON. TEMPERATURES IN THE 90S TO AROUND 100, ALONG WITH
TRIPLE-DIGIT HEAT INDEX VALUES ARE STILL FORECAST ACROSS THE
ENTIRE CWA. THEREFORE, NO CHANGES ARE PLANNED FOR THE EXTREME
HEAT WARNING, WHICH WILL STILL END AT 7 PM TONIGHT.
THE FRONT WILL PUSH THE HIGH PRESSURE RIDGE BACK TO THE WEST,
WHICH WILL BEING RELIEF TO THE HEAT AND HUMIDITY ACROSS THE
REGION FOR SUNDAY AND MONDAY, THOUGH THIS COULD BE TEMPORARY.
SURFACE WINDS WILL BECOME NORTHEAST AND THIS WILL BRING DRIER
DEWPOINTS (IN THE 60S) INTO THE AREA. COMBINED WITH "COOLER"
TEMPERATURES IN THE MID TO UPPER 80S, WE WILL FINALLY GET A
BREAK FROM THE TRIPLE-DIGIT HEAT INDEX VALUES...THOUGH IT WILL
STILL FEEL LIKE SUMMER.
THE UPPER LEVEL RIDGE WILL BECOME FLATTENED AND ELONGATED FROM
WEST TO EAST AS A STRONG TROUGH DEVELOPS IN THE NORTHWEST AND
MOVES EAST ACROSS THE NORTHERN US, GIVING US A ZONAL PATTERN
FOR THE REST OF THE WEEK. THOUGH TEMPERATURES WILL ONCE AGAIN
WARM BACK INTO THE 90S FOR TUE AND WED, THIS WILL ONLY BE FOR A
COUPLE OF DAYS AND THE DEWPOINTS WILL NOT RETURN THE THE 70S FOR
THE REST OF THE WEEK. HEAT INDEX VALUES FOR TUE WILL REMAIN
BELOW 100; HOWEVER, VALUES JUST OVER 100 ARE EXPECTED WED
AFTERNOON SOUTH OF I-72/DANVILLE.
DRY WEATHER IS EXPECTED TUE INTO WED, BUT THE THE FAST ZONAL
FLOW WILL ALLOW A COLD FRONT TO MOVE SOUTH ACROSS THE AREA,
BRINGING A CHANCE OF SHOWERS AND STORMS WED NIGHT INTO THURSDAY.
THIS WILL ALSO BRING COOLER TEMPERATURES TO THE AREA FOR THUR
AND FRIDAY. DUE TO THE ZONAL FLOW, THE FRONT WILL NOT DROP OUT
OF THE CWA; THEREFORE, SMALL CHANCES OF PRECIP OVER PARTS OF THE
CWA WILL HAVE TO BE MAINTAINED FOR FRI AND SAT.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 554 AM CDT SAT SEP 5 2026
VFR CONDITIONS WILL PREVAIL AT ALL SITES NEXT 24HRS. BASED ON
SATELLITE AND FORECAST MODELS, THERE COULD BE SOME SCATTER
CLOUDS DEVELOP THIS MORNING, BUT THESE WILL THIN OUT AND BECOME
FEW AROUND 5-6KFT, LASTING THROUGH THE DAY. BY EVENING THESE
CLOUDS WILL DISSIPATE AND THEN JUST HIGH CIRRUS EXPECTED THIS
EVENING AND OVERNIGHT. LIGHT AND VARIABLE WINDS THIS MORNING,
BUT BECOMING NORTH-NORTHWEST AS THE FRONT MOVES THROUGH. THEN
WINDS SWITCH TO NORTHEAST FOR THE EVENING AND OVERNIGHT. WIND
SPEEDS DURING THE DAYTIME HOURS WILL BE AROUND 10KTS.
CLIMATE
ISSUED AT 1215 AM CDT SAT SEP 5 2026
RECORD HIGH TEMPERATURES FOR SATURDAY:
LOCATION SAT 9/5
======== ========
BLOOMINGTON 103/1899
CHAMPAIGN 102/1899
CHARLESTON 102/1954
DANVILLE 102/1954
DECATUR 104/1954
JACKSONVILLE 104/1899
LINCOLN 103/1954
OLNEY 106/1925
PARIS 105/1954
PEORIA 104/1899
SPRINGFIELD 99/1954
ILX WATCHES/WARNINGS/ADVISORIES
EXTREME HEAT WARNING UNTIL 7 PM CDT THIS EVENING FOR
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
KEY MESSAGES...AUTEN
DISCUSSION...AUTEN
AVIATION...AUTEN
CLIMATE...GEELHART
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