180
FXUS63 KILX 210533
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1233 AM CDT SUN JUN 21 2026
KEY MESSAGES
- WIDESPREAD RAIN WILL OCCUR ACROSS CENTRAL ILLINOIS ON SUNDAY.
AMOUNTS OF 1.50 TO 2.50 WILL BE COMMON...WITH ISOLATED HIGHER
TOTALS WEST OF THE I-55 CORRIDOR.
- THERE IS A SLIGHT RISK (LEVEL 2 OF 5) FOR SEVERE WEATHER ALONG
AND SOUTH OF A JACKSONVILLE TO DANVILLE LINE ON SUNDAY.
DISCUSSION
ISSUED AT 1247 PM CDT SAT JUN 20 2026
*** HEAVY RAINFALL ON SUNDAY ***
12Z JUN 20 CAMS STILL DISPLAY A HIGH DEGREE OF SPREAD
CONCERNING CONVECTIVE TRENDS/TIMING FOR SUNDAY: HOWEVER, THE
OVERALL SYNOPTIC PATTERN REMAINS STRONGLY SUPPORTIVE OF HEAVY
RAINFALL. CLUSTERS OF THUNDERSTORMS WILL FORM ACROSS NEBRASKA
AND NORTHERN KANSAS THIS EVENING, THEN WILL SPREAD ACROSS
IOWA/MISSOURI OVERNIGHT AND INTO WEST-CENTRAL ILLINOIS TOWARD
DAWN SUNDAY. BASED ON THE EXPECTED TRAJECTORY OF THE CONVECTION,
IT APPEARS LOCATIONS NORTH OF THE I-70 CORRIDOR WILL EXPERIENCE
THE HEAVIEST RAINFALL FROM SUNDAY MORNING THROUGH MID-AFTERNOON
BEFORE IT PUSHES FURTHER EASTWARD INTO INDIANA. GIVEN A STRONG
LOW-LEVEL JET STREAK TRANSPORTING COPIOUS MOISTURE NORTHWARD
AND PRECIPITABLE WATER VALUES INCREASING TO 2.00-2.25, THE
SHOWERS/STORMS WILL BE EFFICIENT RAIN-PRODUCERS. 3-HOUR FLASH
FLOOD GUIDANCE RANGES FROM 1.75 TO 2.50 AND AM CONCERNED THE
STRONGEST STORMS WILL BE CAPABLE OF PRODUCING THAT MUCH
RAINFALL. SINCE THE SOIL IS SATURATED AND WATER IS STILL
STANDING IN SOME AREA FIELDS, HAVE EXPANDED THE FLOOD WATCH TO
INCLUDE THE PEORIA AREA NORTHWARD. STORM TOTAL RAINFALL WILL
GENERALLY RANGE FROM 1.50 TO 2.50: HOWEVER, A FEW LOCATIONS
ALONG/WEST OF I-55 COULD POTENTIALLY APPROACH 3 INCHES.
*** SEVERE WEATHER RISK ON SUNDAY ***
AS THUNDERSTORMS SPILL INTO THE ILLINOIS RIVER VALLEY SUNDAY
MORNING, THEY WILL BE NON-SEVERE HEAVY-RAIN PRODUCERS. HOWEVER
AS THE ATMOSPHERE DESTABILIZES TO THE EAST AND SOUTH OF THE
STORMS, THERE IS GROWING CONCERN THAT SOME OF THE CELLS ALONG
THE SOUTHERN PERIPHERY OF THE RAIN AREA COULD BECOME STRONG TO
SEVERE DURING THE AFTERNOON. WHILE THE STRONGEST INSTABILITY
WILL REMAIN FURTHER SOUTH FROM THE OZARKS INTO THE OHIO RIVER
VALLEY WHERE SBCAPES WILL REACH 2000-3000J/KG, INCREASING
DEEP-LAYER SHEAR WITH 0-6KM VALUES CLIMBING ABOVE 40KT WILL
LIKELY BE SUFFICIENT TO PRODUCE ORGANIZED CONVECTION. WHILE CAMS
HAVE NOT YET HONED IN ON AN EXACT SOLUTION, AM MOST CONCERNED
ABOUT LOCATIONS ALONG/SOUTH OF A JACKSONVILLE TO DANVILLE LINE
WHERE LOW-LEVEL SHEAR WILL BE MAXIMIZED IN THE VICINITY OF THE
PREVAILING OUTFLOW BOUNDARY. DAMAGING WIND GUSTS OF AROUND 60MPH
AND HAIL LARGER THAN QUARTERS WILL BE THE PRIMARY RISKS:
HOWEVER, A FEW TORNADOES WILL ALSO BE POSSIBLE. 12Z HREF
SIGNIFICANT TORNADO PARAMETER (STP) VALUES RANGE FROM 1-1.5
ACROSS THIS AREA FROM ROUGHLY 1PM TO 9PM. WHILE THIS EVENT DOES
NOT APPEAR TO BE CLOSE TO THE MAGNITUDE OF JUNE 17, ALL SEVERE
HAZARDS WILL BE POSSIBLE ACROSS THE SOUTHERN KILX CWA DURING THE
AFTERNOON AND EVENING. STAY TUNED TO LATER FORECASTS FOR
ADDITIONAL DETAILS.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1233 AM CDT SUN JUN 21 2026
A STORM SYSTEM WILL SPREAD INCREASINGLY HEAVY RAIN AND EMBEDDED
THUNDERSTORMS INTO THE AREA STARTING AROUND 13Z AND CONTINUING
UNTIL 23Z-03Z BEFORE SHOWERS BEGIN TO TAPER OFF. CONDITIONS
SHOULD BE VFR UNTIL 16Z-18Z BEFORE CIGS AND VSBYS DETERIORATE TO
MVFR. FURTHER DECREASES IN CIGS LOOK TO TAKE PLACE, WITH
WIDESPREAD IFR CIGS EXPECTED BY 23Z-02Z. THUNDERSTORMS COULD BE
ACCOMPANIED BY IFR CONDITIONS AS EARLY AS 16Z-18Z, AS WELL AS
GUSTY AND ERRATIC WINDS. GENERAL WINDS LIGHT AND VARIABLE UNTIL
AROUND 12Z, THEN ESE WINDS INCREASING TO 12-16 KTS WITH GUSTS
20-25 KTS.
ILX WATCHES/WARNINGS/ADVISORIES
FLOOD WATCH FROM 7 AM CDT THIS MORNING THROUGH LATE TONIGHT
FOR ILZ027>031-036>038-040>057-061>063-066>068-071>073.
KEY MESSAGES...BARNES
DISCUSSION...BARNES
AVIATION...37
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