656
FXUS63 KILX 111112
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
612 AM CDT THU JUN 11 2026
KEY MESSAGES
- ANOTHER VERY WARM AND HUMID DAY EXPECTED OVER CENTRAL AND
SOUTHEAST IL, WITH HEAT INDICES PEAKING FROM 95-105 THIS
AFTERNOON.
- THUNDERSTORMS WILL DIMINISH EAST OF THE IL RIVER EARLY THIS
MORNING. ANOTHER ROUND OF THUNDERSTORMS WILL SPREAD SOUTHEAST
ACROSS THE AREA LATE THIS AFTERNOON AND EVENING, AND DIMINISH
LATE EVENING AND OVERNIGHT. THERE IS A SLIGHT TO ENHANCED RISK
OF SEVERE STORMS FOR DAMAGING WIND GUSTS, LARGE HAIL, ISOLATED
TORNADOES AND LOCALIZED FLASH FLOODING.
- MORE SHOWERS AND THUNDERSTORMS ARE LIKELY SATURDAY NIGHT WITH
A MARGINAL RISK OF SEVERE STORMS AND EXCESSIVE RAINFALL OVER
CENTRAL IL.
DISCUSSION
ISSUED AT 345 AM CDT THU JUN 11 2026
SHOWERS AND THUNDERSTORMS WERE SE OF THE IL RIVER TO ALONG I-70
AND TRACKING EASTWARD. THE SEVERE THREAT HAS WANED AS OUTFLOW
WAS PUSHING SE OF STORM COMPLEX AND INSTABILITY WEAKER. BUT
STILL GETTING REPORTS OF MODERATE TO HEAVY RAINS WITH
THUNDERSTORMS, WITH THE HEAVIEST RAINS WERE PUSHING SE OF A
CHAMPAIGN TO SHELBYVILLE LINE. WE ARE GETTING RECENT REPORTS OF
SOME FLOODING ON WEST SIDE OF DECATUR. THE FLOOD WATCH FROM
SANGAMON TO LOGAN TO DEWITT TO MCLEAN COUNTIES UNTIL 7 AM WILL
LIKELY BE ABLE TO CANCEL EARLY ESPECIALLY NW COUNTIES. THIS MCS
WAS SUPPORTED BY SW LOW LEVEL JET UP TO 35-40 KTS EARLIER BUT IS
STARTING TO WEAKEN. LATEST CAMS SHOW CONVECTION PUSHING INTO
SOUTHEAST IL NEXT FEW HOURS AND DIMINISHING BY MID MORNING.
UPSTREAM A NEW MCS WITH CONVECTION WAS DEVELOPING OVER SOUTH
CENTRAL AND SE NEBRASKA. SHOULD THEN BE A LULL IN CONVECTION
PART OF TODAY WITH AREAS NW OF THE IL RIVER HAVING CHANCE OF
CONVECTION BY MID OR LATE AFTERNOON. BREEZY SW WINDS 15-25 MPH
AND GUSTS 25-35 MPH THIS AFTERNOON (STRONGEST NW CWA) TO BRING
VERY WARM CONDITIONS AGAIN TODAY. HIGHS IN THE LOWER 90S FROM
I-72 SOUTH WHERE HEAT INDICES PEAK IN THE LOWER 100S THIS
AFTERNOON. HIGHS 85-90F NORTH OF I-72, WITH AFTERNOON HEAT
INDICES IN THE MID TO UPPER 90S. HREF HAS A 50-80% CHANCE OF
HEAT INDICES OVER 100F THIS AFTERNOON ALONG AND SW OF A
SPRINGFIELD TO TERRE HAUTE LINE.
ANOTHER BAND OF STRONG TO SEVERE CONVECTION TO MOVE SE OVER
THE IL RIVER VALLEY BY LATE AFTERNOON AND OVER REST OF CWA
DURING THIS EVENING, AND DIMINISH LATE EVENING AND OVERNIGHT.
SPC DAY1 OUTLOOK HAS ENHANCED RISK OF SEVERE STORMS FROM
DANVILLE TO LITCHFIELD NW AND SLIGHT RISK SE OF THERE. DAMAGING
WINDS IS BIGGEST SEVERE THREAT WITH 30-45% RISK OF DAMAGING
WINDS IN ENHANCED RISK AREA AND ALSO IN LEVEL 1 FOR WINDS
POTENTIALLY OVER 75 MPH. AREAS NW OF I-55 ARE IN LEVEL 1 FOR
HAIL LARGER THAN 2 INCH DIAMETER. THERE IS A LEVEL 1 FOR EF2
TORNADOES NORTH OF I-72 WITH 10% OR GREATER RISK OF TORNADOES
OVER THE IL RIVER VALLEY. VERY UNSTABLE AIR MASS BY AFTERNOON
WITH MLCAPES 3-4K J/KG WHILE 0-6 KM BULK SHEAR VALUES 25-45
KTS BY LATE AFTERNOON, HIGHEST NW OF I-55. THE LOWEST 1 KM WIND
SHEAR VALUES ARE 15-25 KTS, SO THE KINEMATIC ENVIRONMENT REMAINS
STRONG TODAY. WPC ALSO HAS MARGINAL TO SLIGHT CHANCE OF
EXCESSIVE RAINFALL THIS AFTERNOON AND EVENING, WITH THE SLIGHT
RISK FROM I-72 NORTH AND 25% CHANCE OF EXCEEDING FLASH FLOOD
GUIDANCE OVER KNOX, STARK AND MARSHALL COUNTIES.
AFTER COLD FRONTAL PASSAGE DURING THIS EVENING AND EARLY
OVERNIGHT, EXPECT CONVECTION CHANCES TO DIMINISH BEHIND THE
FRONT WITH DECREASING CLOUDS DURING OVERNIGHT FROM NW TO SE AND
A FAIR AMOUNT OF SUNSHINE FRIDAY AS WEAK HIGH PRESSURE SETTLES
INTO THE MID MS AND LOWER OHIO RIVER VALLEYS. EXPECT COOLER AND
MUCH LESS HUMID AIR ARRIVING ON WNW WINDS. SEASONABLE HIGHS
FRIDAY IN THE LOWER 80S WITH DEWPOINTS MIXING DOWN INTO THE
UPPER 50S/LOWER 60S. COOLER LOWS FRI NIGHT IN THE LOWER 60S WITH
FAIR WEATHER.
A SHORT WAVE TROF TO PIVOT EAST/SE THROUGH THE AREA BY SATURDAY
NIGHT WITH ASSOCIATED SURFACE COLD FRONT PUSHING SE OVER IL.
SW BREEZES SATURDAY WARMS TEMPS INTO THE MID 80S WHILE DEWPOINTS
RISE BACK INTO THE 60S. WILL SEE MORE UNSTABLE AIR MASS MOVING
UP FROM MO INTO CENTRAL/SW IL, WITH THE MOST UNSTABLE AIR OVER
MO AND SOUTHERN IA WHERE SPC HAS SLIGHT RISK OF SEVERE STORMS
LATE SAT AFTERNOON AND SAT EVENING. DEEP LAYER WIND SHEAR ALSO
PRESENT. THERE IS A MARGINAL RISK OF SEVERE STORMS OVER CENTRAL
IL SAT NIGHT. WPC ERO HAS MARGINAL RISK OF EXCESSIVE RAINFALL
OVER CENTRAL IL SAT NIGHT. A CHANCE OF SHOWERS/THUNDERSTORMS MAY
LINGER IN SOUTHEAST IL SUNDAY MORNING, OTHERWISE DRY, COOLER AND
LESS HUMID AIR RETURNS ON SUNDAY. HIGHS SUNDAY IN THE MID 70S IN
CENTRAL IL AND 75-80F IN SOUTHEAST IL.
EXTENDED FORECAST MODELS AND THEIR ENSEMBLES CONTINUES TO SHOW A
BROAD MID/UPPER LEVEL TROF OVER THE MIDWEST, GREAT LAKES AND
OHIO RIVER VALLEY FROM SUNDAY THROUGH THE MIDDLE OF NEXT WEEK.
THERE ARE NORTHERN STREAM SHORT WAVES THAT PASS THROUGH THIS
TROF AT TIMES AND COULD BRING CHANCES OF SHOWERS AND ISOLATED
THUNDERSTORMS TO CENTRAL IL AROUND TUE AND AGAIN WED AFTERNOON
INTO THU. HIGHS MONDAY IN THE MID TO UPPER 70S ARE UPPER
70S/LOWER 80S TUE/WED.
AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
ISSUED AT 612 AM CDT THU JUN 11 2026
AN AREA OF IFR CEILINGS HAS DEVELOPED WHERE SKIES CLEARED OUT
EARLIER, WITH THE MOIST GROUND FROM RECENT HEAVY RAIN. MAIN
IMPACTS HAVE BEEN WEST OF A KPIA-KIJX LINE, BUT HAVE STARTED TO
SHOW SOME BREAKUP WITH SUNRISE. THINK THIS SHOULD BE GONE BEFORE
14Z.
SOUTHWEST WINDS WILL INCREASE TODAY AND GUST FROM 20-30 KNOTS BY
ABOUT MIDDAY, LINGERING UNTIL PASSAGE OF A COLD FRONT THIS
EVENING. THIS FRONT WILL BRING A LINE OF SEVERE CONVECTION WITH
IT, WITH A SHORT PERIOD OF IFR VISIBILITIES IN THE HEAVIER RAIN.
THE MAIN PERIOD OF CONCERN FOR THE TERMINALS IS FROM 23-03Z.
ONCE THE FRONT PASSES, WINDS SHIFT TO THE WEST, AND GRADUALLY
DIMINISH AFTER MIDNIGHT.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...07
DISCUSSION...07
AVIATION...GEELHART
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page