498
FXUS63 KILX 251657
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1157 AM CDT THU JUN 25 2026
KEY MESSAGES
- ISOLATED SEVERE STORMS THROUGH SATURDAY: SCATTERED
THUNDERSTORMS LATE THIS AFTERNOON THROUGH THURSDAY EVENING
BRING A THREAT OF ISOLATED DAMAGING WIND GUSTS TO AREAS SOUTH
OF I-72/DANVILLE. ISOLATED SEVERE STORMS REMAIN A THREAT
FRIDAY INTO FRIDAY NIGHT ACROSS THE SAME AREA, WITH ISOLATED
DAMAGING WINDS AND A TORNADO THE MAIN THREAT. THE ISOLATED
SEVERE THREAT FOR DAMAGING WINDS WILL CONTINUE SATURDAY
AFTERNOON INTO SATURDAY NIGHT BUT WILL SHIFT TO AREAS ALONG
AND SOUTH OF I-74.
- HEAVY RAINFALL AND FLOODING: MULTIPLE ROUNDS OF STORMS WILL
BRING A HEAVY RAINFALL AND FLOOD THREAT FROM TONIGHT THROUGH
SATURDAY MORNING. THERE IS A 65-75% CHANCE THAT RAINFALL
TOTALS WILL EXCEED 1.5 INCHES FOR LOCATIONS SOUTH OF A
JACKSONVILLE TO PARIS LINE.
- DANGEROUS HEAT NEXT WEEK: A PROLONGED PERIOD OF OPPRESSIVE
HEAT AND HUMIDITY BUILDS INTO THE REGION SUNDAY THROUGH
WEDNESDAY. HIGH CONFIDENCE EXISTS THAT DAILY HEAT INDEX
VALUES WILL CONSISTENTLY BE AROUND 105 DEGREES ACROSS THE
AREA.
DISCUSSION
ISSUED AT 348 AM CDT THU JUN 25 2026
THE WEAK FRONT THAT BROUGHT SCATTERED STORMS TO THE AREA LAST
NIGHT WILL CONTINUE TO DRIFT SLOWLY SOUTH TOWARD SOUTHEAST
ILLINOIS BY THIS EVENING. SCATTERED SHOWERS AND STORMS ARE
EXPECTED TO CONTINUE TO DEVELOP ALONG THIS SEMI-STATIONARY
BOUNDARY THIS AFTERNOON INTO THIS EVENING. THEN LATE TONIGHT,
THE FIRST OF MULTIPLE ROUNDS OF SHOWERS AND STORMS IS EXPECTED
TO MOVE INTO THE AREA WITH STRONG STORMS CAPABLE OF HEAVY
RAINFALL. ADDITIONAL ROUNDS OF STORMS WITH HEAVY RAINFALL ARE
EXPECTED THROUGH FRIDAY WITH THE MAIN LOW PRESSURE AREA AND
FRONTAL SYSTEM PUSHING EAST FRIDAY NIGHT. GIVEN THE SEMI-
STATIONARY BOUNDARY, WEAK SHEAR ALONG THE BOUNDARY, PW VALUES
OVER 2 INCHES, THE POSSIBILITY OF TRAINING CELLS, AND THESE
STORMS MOVING OVER AREAS THAT HAD SOME RECENT HEAVY RAINS LAST
WEEKEND; BELIEVE FLASH FLOODING WILL BE AN ISSUE OVER ON FRIDAY.
MODELS ARE IN GOOD AGREEMENT ON THE FORECAST POSITION OF THE
FRONT BEING ACROSS SOUTHWEST TO SOUTHEAST IL THROUGH THE PERIOD,
SO FLOOD WATCH LOCATION LOOKS GOOD. HOWEVER, SOME GUIDANCE IS
PUSHING SOME OF THE HEAVY RAINFALL A LITTLE MORE NORTH, SO HAVE
ADDED A ROW OF COUNTIES TO THE CURRENT WATCH AND KEPT THE SAME
TIME PERIOD. THERE IS A 65-75% PROBABILITY OF RAINFALL ACROSS
THE WATCH AREA BEING OVER 1.5 INCHES. THIS IS A LITTLE LOWER
THAN YESTERDAY AFTERNOON'S FORECAST, BUT POCKETS OF AROUND 2
INCHES OF RAINFALL IS STILL POSSIBLE.
NOT TO BE FORGOTTEN, BUT ISOLATED SEVERE STORMS ARE ALSO
POSSIBLE THIS AFTERNOON THROUGH SATURDAY NIGHT. THE MAIN THREAT
WILL BE DAMAGING WINDS, BUT AN ISOLATED TORNADO OR TWO IS
POSSIBLE FRIDAY AFTERNOON AND EVENING IN SOUTHEAST IL.
ONCE THIS SYSTEM MOVES TO THE EAST, A SUMMERTIME RIDGE WILL
BUILD INTO THE MIDWEST. FORECAST FOR HOT AND HUMID CONDITIONS
HAS NOT CHANGED FROM THE LAST TWO DAYS AS ALL GUIDANCE CONTINUES
TO SHOW DEWPOINTS STILL GETTING INTO THE MID 70S AND HIGHS
REACHING INTO THE LOWER TO MIDDLE 90S FROM SUNDAY AFTERNOON
THROUGH WEDNESDAY. THEREFORE, CONFIDENCE IS QUITE HIGH THAT HEAT
INDICIES WILL REACH ABOVE 100 OVER MOST OF THE AREA FOR ALL
FOUR DAYS.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1151 AM CDT THU JUN 25 2026
CLOUDS WILL GRADUALLY INCREASE THIS EVENING IN THE VICINITY OF A
SURFACE FRONT DISPLACED JUST SOUTH OF THE REGIONAL TERMINALS.
OVERNIGHT INTO FRIDAY MORNING, THESE CLOUDS WILL THICKEN AND
LOWER AS THE SURFACE FRONT SLOWLY LIFTS NORTHWARD. MVFR
CEILINGS ARE FORECAST TO SPREAD OVER THE REGIONAL TERMINALS
BETWEEN 08Z-12Z, WITH WIDESPREAD SHOWERS FORECAST TO MOVE IN
DURING OR JUST AFTER THAT TIME AND PERSISTING FOR THE REMAINDER
OF THIS TAF CYCLE. VISIBILITY MAY ALSO OCCASIONALLY FALL INTO
THE MVFR RANGE WITHIN HEAVIER BANDS OF SHOWERS.
SURFACE WINDS WILL GRADUALLY VEER, BECOMING EAST BETWEEN 5-10
KTS BY FRIDAY MORNING AS THE SURFACE FRONT MOVES OVER THE
REGION.
ILX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH FROM 4 PM CDT THIS AFTERNOON THROUGH SATURDAY
AFTERNOON FOR ILZ049>057-061>063-066>068-071>073.
KEY MESSAGES...AUTEN
DISCUSSION...AUTEN
AVIATION...MJA
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