951
FXUS63 KILX 171747
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1247 PM CDT WED JUN 17 2026
KEY MESSAGES
- A DANGEROUS SEVERE WEATHER OUTBREAK IS PROJECTED FOR FOR
CENTRAL IL TODAY, CAPABLE OF STRONG/INTENSE TORNADOES
(EF2-EF3+ DAMAGE), DAMAGING WIND GUSTS OF 75+ MPH, AND 2+ INCH
HAIL.
- HEAVY RAINFALL RATES WILL CREATE A RISK OF LOCALIZED FLASH
FLOODING TODAY. THERE IS A FLOOD WATCH OUT FOR THE AREAS ALONG
AND NORTH OF A FULTON COUNTY TO MCLEAN COUNTY LINE FROM 7AM TO
10PM.
- STRONG, NON-CONVECTIVE GRADIENT WINDS ARE ANTICIPATED THIS
AFTERNOON, WITH WIDESPREAD SOUTHWEST GUSTS NEAR 50 MPH,
PARTICULARLY FOR AREAS NEAR AND SOUTH OF I-72. A WIND ADVISORY
WILL BE IN EFFECT FROM 12PM TO 7PM.
DISCUSSION
ISSUED AT 307 AM CDT WED JUN 17 2026
BOTTOM LINE UP FRONT: STAY WEATHER AWARE ALL DAY LONG TODAY AND KNOW
WHERE YOUR SAFEST SHELTER IS WHEN/IF A WARNING IS ISSUED FOR YOUR
LOCATION TODAY. AN OUTBREAK OF SEVERE WEATHER IS EXPECTED LATER
TODAY.
SPC HAS MAINTAINED A MODERATE RISK (LEVEL 4 OF 5) WITH AN ENHANCED
RISK (LEVEL 3 OF 5) OVER (BASICALLY) THE REST OF THE FORECAST AREA.
A WARM FRONT WILL PUSH NORTH, LIFTING BETTER MOISTURE (DEWPOINTS IN
THE 70S AND PWATS ~2 INCHES) INTO CENTRAL AND SOUTHEASTERN IL. A
MORNING ROUND OF CONVECTION WILL TRAVEL ALONG AND NORTH OF THE WARM
FRONT ASSOCIATED WITH THE STRONG LLJ THIS MORNING. IF A SUPERCELL
CAN LATCH ONTO THE WARM FRONT, TORNADOES CAN BE POSSIBLE. OTHERWISE,
LARGE HAIL AND DAMAGING WINDS ARE THE CONCERN FOR THE MORNING ROUND.
THIS ROUND WILL ENTER THE NORTHERN PART OF THE FORECAST AREA BY 13Z
(8AM) AND WILL TRAVEL EAST ACROSS THE STATE. THERE IS SOME
UNCERTAINTY OF HOW FAR SOUTH THAT AREA OF STORMS WILL MAKE IT BUT
SOME GUIDANCE IS NOW SUGGESTING AS FAR SOUTH AS I-70. THERE IS SOME
OVERLAP IN TIMING WITH THE AFTERNOON "BIG SHOW". THE EARLY ROUND
WILL BE EXITING THE EAST/SOUTHEAST COUNTIES BY ~20Z (4PM), WHICH IS
ABOUT THE TIME THE LINE OF STORMS WILL BE DEVELOPING IN WESTERN IL.
SOME UNCERTAINTY ON HOW FAR NORTH THE WARM FRONT WILL GET STILL
EXISTS. GUIDANCE IS STILL SHOWING IT LIFTING SOMEWHERE BETWEEN I-74
AND I-80. IF THE WARM FRONT DOESN'T GET AS FAR NORTH AS I-80, THEN
THE MODERATE RISK THREAT COULD POSSIBLY BE PUSHED FURTHER SOUTH FOR
THE COLD FRONTAL PASSAGE AND ASSOCIATED THUNDERSTORMS IN THE
AFTERNOON FROM 20Z-05Z (3PM-12AM). THE ENVIRONMENT WILL BE VERY
VOLATILE AND CAPABLE OF STRONG/INTENSE TORNADOES (EF2-EF3+ DAMAGE),
DAMAGING WIND GUSTS OF 75+ MPH, AND 2+ INCH HAIL. CAPE VALUES 2000-
3000 J/KG, INSANE AMOUNT OF EFFECTIVE BULK SHEAR VALUES (60-70
KNOTS), AND SRH 0-1 KM OF ~250-450 M2/S2. MID LEVEL LAPSE RATES ARE
MORE THAN SUFFICIENT FOR LARGE TO VERY LARGE HAIL (7.6-8.1 C/KM).
SUPERCELLS ARE THE EXPECTED MODE THROUGH MOST OF THE EVENT THIS
AFTERNOON INTO EVENING, BUT MAY BEGIN TO EVOLVE INTO A FAST MOVING
LINEAR SYSTEM AS IT NEARS EXITING THE SOUTHEASTERN COUNTIES. THE
SUPERCELLS HAVE THE PERFECT ENVIRONMENT TO BE LONG-LIVED. THESE
STORMS ARE GOING TO BE MOVING VERY FAST, WITH STORM MOTIONS NEARLY
DUE EAST AT 50-60 KNOTS.
WPC HAS KEPT AN EXCESSIVE RAINFALL HIGH-END SLIGHT RISK FOR CENTRAL
AND SOUTHEASTERN IL TODAY, BUT OUR NORTHERN MOST COUNTIES HAVE BEEN
CLIPPED BY THE MODERATE RISK AREA. PWATS OF 1.8-2.1 INCHES ARE
FORECAST. THE STORMS TODAY WOULD LIKELY HAVE TORRENTIAL RAIN WITHIN
THEM, BUT WILL BE MOVING FAIRLY FAST, WHICH WOULD HOPEFULLY HELP
CURB THE FLOODING THREAT FOR MOST PLACES. WITH MANY RIVERS/STREAMS
ALREADY AT OR NEAR FLOOD AND SATURATED SOILS, FLOODING COULD BECOME
A CONCERN THROUGH THE EVENT. THERE IS A FLOOD WATCH OUT FOR THE
AREAS ALONG AND NORTH OF A FULTON COUNTY TO MCLEAN COUNTY LINE FROM
12Z TO 03Z (7AM-10PM) TODAY. REMEMBER, TURN AROUND, DON'T DROWN!
OUTSIDE OF THE SEVERE WEATHER TODAY, THERE ARE VERY STRONG WINDS
ASSOCIATED WITH THIS SYSTEM. THERE IS A WIND ADVISORY IN PLACE FROM
SCHUYLER COUNTY TO VERMILION COUNTY FROM 18Z TO 00Z (1PM-7PM)
TODAY. SOUTHERLY WINDS WILL GUST TO 35-45 MPH DURING THAT TIME.
AFTER TODAY, IT LOOKS LIKE WE GET TWO DAYS OF A BREAK. FRIDAY AND
SATURDAY APPEAR TO BE PLEASANT WITH HIGHS IN THE UPPER 70S TO MID
80S AND PLENTY OF SUNSHINE. ADDITIONAL RAIN CHANCES RETURN TO THE
FORECAST FOR SUNDAY INTO MONDAY.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1247 PM CDT WED JUN 17 2026
CONVECTION IS ONGOING ACROSS CENTRAL ILLINOIS EARLY THIS
AFTERNOON: HOWEVER, 1740Z/1240PM RADAR IMAGERY SHOWS THE BACK
EDGE OF THE PRECIP ALONG A KGBG TO KSPI LINE. BASED ON
RADAR/SATELLITE TRENDS, IT APPEARS THE TERMINALS WILL SEE A
COUPLE HOUR BREAK AS THE AFTERNOON PROGRESSES BEFORE A FINAL
LINE OF THUNDERSTORMS FORMS FROM THE IOWA/MISSOURI BORDER
EASTWARD INTO THE AREA AFTER 19Z/20Z. FOLLOWING THE LATEST
HRRR/RAP SOLUTION CLOSELY, HAVE HIGHLIGHTED THUNDER WITH VISBYS
DOWN TO 1 MILE AT KPIA BETWEEN 19Z AND 21Z...THEN FURTHER SOUTH
TO THE I-72 SITES BETWEEN 22Z AND 00Z. ONCE THE CONVECTIVE LINE
SETTLES FURTHER SOUTH, SCATTERED SHOWERS WILL REMAIN POSSIBLE
UNTIL EARLY EVENING. AFTER THAT, AM EXPECTING SKIES TO BECOME
MOSTLY CLEAR THROUGH MUCH OF THE EVENING BEFORE A LAYER OF
MID-LEVEL CLOUDS AOA 15,000FT SPREADS ACROSS THE AREA BY
THURSDAY MORNING. WINDS ARE HIGHLY VARIABLE AT THE MOMENT DUE TO
ONGOING STORMS, BUT WILL BECOME SOUTHEASTERLY THIS
AFTERNOON...THEN WESTERLY THIS EVENING AS A COLD FRONT PASSES.
ILX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH UNTIL 10 PM CDT THIS EVENING FOR ILZ027>031-
036>038.
WIND ADVISORY UNTIL 7 PM CDT THIS EVENING FOR ILZ040>057-
061>063-066>068-071>073.
KEY MESSAGES...COPPLE
DISCUSSION...COPPLE
AVIATION...BARNES
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