513
FXUS63 KILX 152319
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
619 PM CDT SAT AUG 15 2026
KEY MESSAGES
- FLOODING CONTINUES ACROSS PORTIONS OF CENTRAL IL IN A CORRIDOR
FROM FULTON AND SOUTHERN KNOX COUNTY TO VERMILION COUNTY DUE
TO 4 TO 7 INCHES OF RAIN THAT FELL OVERNIGHT.
- ADDITIONAL CLUSTERS OF THUNDERSTORMS ARE LIKELY TONIGHT INTO
SUNDAY MORNING, WITH ISOLATED AFTERNOON THUNDERSTORMS POSSIBLE
SUNDAY AFTERNOON. STORMS HAVE THE POTENTIAL TO PRODUCE LOCALLY
DAMAGING WINDS. SPC HAS A MARGINAL (LEVEL 1 OF 5) RISK OF
SEVERE WEATHER.
- THE HEAT AND HUMIDITY REMAIN A CONCERN THIS WEEKEND, WITH THE
HOTTEST CONDITIONS SOUTH OF I-70.
DISCUSSION
ISSUED AT 156 PM CDT SAT AUG 15 2026
IN THE WAKE OF WIDESPREAD THUNDERSTORM ACTIVITY THIS MORNING,
HEAT HAS ONCE AGAIN BEEN TEMPERED OVER MUCH OF THE AREA WITH
SOME LATE AFTERNOON RECOVERY EXPECTED TO BRING TEMPERATURES BACK
UP TO THE LOW 90S BY AFTERNOON IN A CORRIDOR FROM JACKSONVILLE
TO ROBINSON, WITH HEAT INDEX LIKELY TO REACH AROUND 105 SOUTH OF
I-70 AS A WARM FRONT LIFTS NORTHWARD THROUGH THE AREA. MID TO
UPPER 80S CAN BE EXPECTED TO THE NORTH.
A FEW SHOWERS REMAIN IN THIS FRONTAL ZONE, WHERE PERHAPS A FEW
THUNDERSTORMS COULD DEVELOP THIS AFTERNOON AS DIURNAL
DESTABILIZATION GRADUALLY TAKES PLACE.
TONIGHT, A COLD FRONT WILL APPROACH FROM THE NORTHWEST, WITH
WARM ADVECTION AHEAD OF THE FRONT PROMOTING ANOTHER CLUSTER OR
TWO OF THUNDERSTORMS. AREAS OF SIGNIFICANT PRECIPITATION ARE
POSSIBLE, ALTHOUGH MUCH LESS LIKELY THAN LAST NIGHT. THE
LOCATION OF ANY HEAVY PRECIPITATION SWATHS REMAINS TOO UNCERTAIN
FOR A FLOOD WATCH AT THIS POINT, BUT WE WILL CONTINUE TO
EVALUATE ANY CORRIDORS FOR POTENTIAL WATCH ISSUANCE. IF EXPECTED
HEAVY PRECIPITATION CORRIDORS LINE UP WELL WITH LAST NIGHT'S
HEAVY PRECIPITATION FROM FULTON TO VERMILION COUNTY THESE WOULD
BE FAVORABLE FOR RENEWED FLOODING. 12Z HIGH-RES AVERAGE MODEL
GUIDANCE POINTS TO A 1.5 TO 1.5 INCH CORRIDOR NORTH OF PEORIA
AND BLOOMINGTON, ALTHOUGH THERE REMAIN CONSIDERABLE RUN-TO-RUN
AND MODEL-TO-MODEL DISCREPANCIES. SPC CONTINUES A MARGINAL RISK
FOR LOCALLY DAMAGING WINDS WITH THUNDERSTORMS BOTH TONIGHT AND
SUNDAY AS THESE STORMS MOVE ACROSS CENTRAL IL AND SOME AFTERNOON
THUNDERSTORMS AS DIURNAL DESTABILIZATION TAKES PLACE AND THE
COLD FRONT LINGERS OVER THE SOUTHEAST HALF OF CENTRAL IL.
A COUPLE OF DRY DAYS ARE FORECAST MONDAY AND TUESDAY BEHIND
SUNDAY'S FRONT, THEN ANOTHER COLD FRONT MIDWEEK WILL BRING THE
NEXT CHANCE FOR THUNDERSTORMS.
TEMPERATURES WILL REMAIN QUITE WARM AND HUMID FOR CENTRAL IL AS
2 INCH PRECIPITABLE WATER VALUES KEEP DEWPOINTS WELL INTO THE
70S AND HIGHS REACH THE 80S, TO LOWER 90S SOUTH OF I-70. A HEAT
ADVISORY CONTINUES FOR AREAS SOUTH OF I-70 UNTIL SUNDAY EVENING
AS HEAT INDEX VALUES WILL NEAR 105 EACH AFTERNOON UNTIL THEN.
HIGHS WILL BE IN THE 80S ACROSS THE AREA MONDAY THROUGH
TUESDAY, THEN THE MIDWEEK FRONT WILL CONTINUE TO LOWER
TEMPERATURES FOR LATE IN THE WEEK, WITH SOME UPPER 70S POSSIBLE.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 617 PM CDT SAT AUG 15 2026
ANOTHER ROUND OF SHOWERS AND THUNDERSTORMS IS EXPECTED ACROSS
CENTRAL ILLINOIS LATE THIS EVENING AND OVERNIGHT. STORMS HAVE
STARTED TO REDEVELOP OVER NORTHERN MO AND SOUTHERN IA EARLY THIS
EVENING AND WILL GRADUALLY SPREAD EAST ACROSS CENTRAL ILLINOIS
TONIGHT. A PERIOD OF MVFR CEILINGS IS FAVORED AT PIA/BMI AT
TIMES THIS EVENING THROUGH SUNDAY MORNING. SOUTH WINDS IN PLACE
TODAY WILL SET UP OUT OF THE WEST TO NORTHWEST SUNDAY.
ILX WATCHES/WARNINGS/ADVISORIES
HEAT ADVISORY UNTIL 8 PM CDT SUNDAY FOR ILZ066>068-071>073.
KEY MESSAGES...COPPLE
DISCUSSION...37
AVIATION...DEUBELBEISS
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