530
FXUS63 KILX 180132
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
832 PM CDT WED JUN 17 2026
KEY MESSAGES
- A TORNADO WATCH IS IN EFFECT UNTIL 10PM CDT FOR LOCATIONS
ALONG AND SOUTH OF A MACOMB TO CHENOA LINE. ALL SEVERE HAZARDS
ARE POSSIBLE...WITH THE GREATEST PROBABILITY FOR STRONG
TORNADOES FOCUSING SOUTH OF A SPRINGFIELD TO PARIS LINE.
- QUIET WEATHER WILL PREVAIL THURSDAY THROUGH SATURDAY...WITH
THE NEXT CHANCE FOR THUNDERSTORMS ARRIVING BY SUNDAY.
UPDATE
ISSUED AT 832 PM CDT WED JUN 17 2026
THE SEVERE THREAT HAS DRIFTED NEAR AND SOUTH OF I-72/DANVILLE
NOW. WE ARE STILL EXPECTING POTENTIALLY STRONG TO INTENSE, LONG
TRACK TORNADOES, VERY LARGE HAIL, AND DAMAGING WIND GUSTS OF
75+ MPH FOR THE NEXT FEW HOURS. REMAIN WEATHER AWARE AND KNOW
WHERE YOUR SAFE SHELTER IS.
IF YOU ARE NORTH OF A CASS COUNTY TO DEWITT COUNTY LINE, YOU
SHOULD BE IN THE CLEAR FOR THIS EVENT.
DISCUSSION
ISSUED AT 316 PM CDT WED JUN 17 2026
19Z/2PM MESOANALYSIS SHOWS AN OUTFLOW BOUNDARY LEFT BEHIND BY
THE MORNING CONVECTION ALONG A QUINCY...TO LITCHFIELD...TO
SALEM LINE. THIS IS CONSIDERABLY FURTHER SOUTH THAN PREVIOUSLY
THOUGHT: THEREFORE THE MOST SIGNIFICANT RISK FOR WIDESPREAD
SEVERE WEATHER LATER THIS AFTERNOON AND EVENING HAS SHIFTED
SOUTH AS WELL. AS SUCH, THE NEW TORNADO WATCH COORDINATED WITH
SPC DOES NOT INCLUDE THE FAR NORTHERN KILX CWA FROM THE PEORIA
AREA NORTHWARD.
MLCAPES ARE CURRENTLY UNDER 1000J/KG: HOWEVER, AS THE BOUNDARY
MIXES SLOWLY NORTHWARD THIS AFTERNOON, THE RAP SUGGESTS MLCAPES
WILL INCREASE INTO THE 1500-2000J/KG ALONG/SOUTHEAST OF A QUINCY
TO CHAMPAIGN LINE OVER THE NEXT COUPLE OF HOURS. IMPRESSIVE WIND
FIELDS ALOFT ARE CONTRIBUTING TO VERY STRONG 0-6KM BULK SHEAR
OF 60-80KT...WHILE 0-1KM SHEAR VALUES REMAIN IN THE 30-40KT
RANGE. GIVEN MARGINAL INSTABILITY AND EXTREME SHEAR, AM
EXPECTING SUPERCELL THUNDERSTORMS TO RAPIDLY DEVELOP ALONG/AHEAD
OF A SLOWLY ADVANCING COLD FRONT ACROSS THE ILLINOIS RIVER
VALLEY IMMINENTLY. ALL SEVERE HAZARDS WILL BE IN PLAY...INCLUDING
DAMAGING WIND GUSTS IN EXCESS OF 70MPH, HAIL LARGER THAN
GOLF BALLS, AND TORNADOES. THE SIGNIFICANT TORNADO PARAMETER
(STP) IS CURRENTLY MAXIMIZED CLOSER TO THE OUTFLOW BOUNDARY
FROM CENTRAL/NORTHERN MISSOURI ACROSS SOUTH-CENTRAL ILLINOIS,
BUT IS PROGGED TO LIFT NORTHWARD LATER THIS AFTERNOON/EVENING.
AT THIS TIME, IT APPEARS THE HIGHEST PROBABILITY OF POTENTIALLY
STRONG TORNADOES WILL FOCUS ALONG/SOUTH OF A SPRINGFIELD TO
PARIS LINE.
THUNDERSTORMS ARE CURRENTLY DEVELOPING IN A BAND FROM
GALESBURG/RUSHVILLE EASTWARD TO PONTIAC/CHAMPAIGN. CAMS HAVE
GENERALLY SPED UP THE DEVELOPMENT PROCESS, AS WELL AS THE
GRADUAL S/SE MOVEMENT OF THE BAND. AS A RESULT, THINK THE
PRIMARY SEVERE RISK WILL BE FOCUSED ALONG THE I-72 CORRIDOR
BETWEEN 4PM AND 6PM, THEN WILL SINK TOWARD I-70 BY 7PM TO 9PM.
THE PRIMARY LINE OF CONVECTION WILL EXIT THE FAR SE KILX CWA
AROUND MIDNIGHT: HOWEVER, A FEW SHOWERS MAY LINGER FURTHER NORTH
THROUGHOUT THE EVENING INTO THE FIRST PART OF THE OVERNIGHT.
A SHORT-WAVE TROUGH WILL BRING A PERIOD OF MID-LEVEL CLOUDINESS
TO CENTRAL ILLINOIS THURSDAY MORNING, WITH FORECAST SOUNDINGS
SUGGESTING THE POTENTIAL FOR A FEW LIGHT RAIN SHOWERS MOSTLY
ALONG/SOUTH OF A RUSHVILLE TO ROBINSON LINE WHERE SLIGHT CHANCE
POPS (20%) ARE WARRANTED. ONCE THIS WAVE DEPARTS, A RETURN TO
COOL AND MOSTLY DRY WEATHER WILL BE ON TAP FOR FRIDAY AND
SATURDAY. THE NEXT SIGNIFICANT CHANCE FOR PRECIPITATION WILL
HOLD OFF UNTIL LATE SATURDAY NIGHT INTO SUNDAY AS A STRONGER
SHORT-WAVE TROUGH TRAVERSES THE PLAINS AND APPROACHES FROM THE
WEST. GIVEN BETTER DEEP-LAYER MOISTURE AND STRONG FORCING, THINK
SHOWERS AND THUNDERSTORMS WILL BECOME WIDESPREAD. THE SEVERE
WEATHER RISK REMAINS UNCERTAIN AT THIS TIME, WITH SEVERAL
MACHINE LEARNING ALGORITHMS SUCH AS COLORADO STATE AND NSSL
KEEPING THE GREATEST PROBABILITIES FURTHER SOUTH. A FEW NCAR
MEMBERS DO HOWEVER SUGGEST 15-30% PROBS NORTHWARD INTO CENTRAL
ILLINOIS, SO WILL NEED TO KEEP AN EYE ON MESOSCALE DETAILS AS
THE TIME NEARS.
AVIATION /00Z TAFS THROUGH 00Z FRIDAY/
ISSUED AT 629 PM CDT WED JUN 17 2026
A LINE OF SCATTERED BUT INTENSE CONVECTION LOCATED ALONG THE
I-72 CORRIDOR WILL CONTINUE TO GRADUALLY PUSH EAST-SOUTHEAST OF
THE TERMINALS THROUGH ABOUT 02-04Z. CONVECTIVE IMPACTS WILL BE
GREATEST AT SPI, DEC, AND CMI, WHERE BRIEF LIFR VSBYS AND
VARIABLE AND GUSTY THUNDERSTORM WINDS ARE EXPECTED. SKIES WILL
GRADUALLY CLEAR OVERNIGHT, WITH WINDS BECOME STEADY FROM THE W
TO WNW AROUND 8-12 KTS. AFTER 12Z, DIURNAL CU WITH BASES AROUND
5KFT WILL DEVELOP WITH STEADY NW AROUND 10-15 KTS.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BARNES
UPDATE...COPPLE
DISCUSSION...BARNES
AVIATION...BARNES
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