519
FXUS63 KILX 221043
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
543 AM CDT TUE SEP 22 2026
KEY MESSAGES
- NO SIGNIFICANT WEATHER IS ANTICIPATED ACROSS CENTRAL ILLINOIS
OVER THE NEXT WEEK.
DISCUSSION
ISSUED AT 315 AM CDT TUE SEP 22 2026
07Z/2AM SURFACE ANALYSIS SHOWS A 1032MB HIGH ANCHORED OVER
ONTARIO/QUEBEC WHILE A STATIONARY FRONTAL BOUNDARY IS DRAPED
FROM THE SOUTHERN APPALACHIANS TO TEXAS. DESPITE SYNOPTIC
SUBSIDENCE AND A DRYING E/NE FLOW FROM THE GREAT LAKES, AMPLE
CLOUD COVER REMAINS LOCKED IN PLACE ACROSS THE MIDWEST EARLY
THIS MORNING. THE LATEST IR SATELLITE IMAGERY SHOWS A FEW BREAKS
IN THE LOW OVERCAST...MOST NOTABLY ALONG/JUST SOUTH OF I-70 AND
ALONG I-55 FROM CHICAGO TO LINCOLN. GIVEN CONTINUED E/NE FLOW,
MOST CAMS SHOW WIDESPREAD CLOUD COVER UPSTREAM ACROSS INDIANA
SPILLING BACK WESTWARD ACROSS MUCH OF CENTRAL ILLINOIS AS THE
MORNING PROGRESSES. THE EXCEPTION WILL BE ALONG/WEST OF I-55
WHERE PARTIAL CLEARING APPEARS LIKELY. AS AN UPPER-LEVEL LOW
EVIDENT ON WATER VAPOR IMAGERY OVER EASTERN IOWA SLOWLY TRACKS
EASTWARD, A FEW VERY LIGHT SHOWERS OR SPRINKLES WILL BE
POSSIBLE. WHILE THE NAM SUGGESTS MUCAPES WILL REMAIN BELOW
100J/KG, THINK THIS MAY BE A BIT UNDERDONE GIVEN THE EXPECTED
BREAKS IN THE OVERCAST. WITH SUFFICIENT MOISTURE/FORCING AND
RRFS 700-500MB LAPSE RATES OF AROUND 6-7C/KM, HAVE MENTIONED
ISOLATED SHOWERS/SPRINKLES ALONG/NORTH OF THE I-72 CORRIDOR
THROUGH THE AFTERNOON. HIGH TEMPERATURES WILL MOSTLY BE IN THE
MIDDLE TO UPPER 60S, WITH LOWER 70S ALONG/SOUTH OF I-70.
WHILE SURFACE RIDGING WILL BUILD INTO THE REGION TONIGHT,
PERSISTENT BOUNDARY LAYER MOISTURE BENEATH THE SUBSIDENCE
INVERSION WILL CREATE A CHALLENGING CLOUD COVER FORECAST. WHILE
PREVIOUS THINKING SUGGESTED PARTLY TO MOSTLY CLEAR SKIES AND
GOOD RADIATIONAL COOLING CONDITIONS OVERNIGHT, THE LATEST DATA
INDICATES THE LOW CLOUD COVER REMAINING IN PLACE AND/OR
SPREADING BACK WESTWARD ACROSS MUCH OF THE KILX CWA. AS A
RESULT, THINK PARTIAL CLEARING WILL BE LIMITED TO THE ILLINOIS
RIVER VALLEY WITH CLOUDY SKIES FURTHER EAST. DUE TO THE
INCREASED CLOUD COVER, HAVE RAISED LOW TEMPERATURES BY A FEW
DEGREES...RANGING FROM THE LOWER 50S NORTHWEST OF THE ILLINOIS
RIVER TO THE UPPER 50S ALONG/EAST OF I-57.
MOSTLY CLOUDY CONDITIONS WITH BELOW NORMAL TEMPERATURES IN THE
UPPER 60S AND LOWER 70S WILL CONTINUE INTO WEDNESDAY BEFORE
INCREASING AMOUNTS OF SUNSHINE SLOWLY PUSH READINGS BACK INTO
THE LOWER TO MIDDLE 70S BY FRIDAY/SATURDAY. AFTER THAT, A
BLOCKING PATTERN WILL DEVELOP ACROSS THE EASTERN CONUS FEATURING
A DEEP UPPER LOW OVER THE MID-ATLANTIC REGION AND A RIDGE OF
HIGH PRESSURE FURTHER WEST ACROSS THE MIDWEST. AS A RESULT, IT
APPEARS A RETURN TO ABOVE NORMAL TEMPERATURES IN THE 80S IS IN
STORE FOR CENTRAL ILLINOIS BY EARLY NEXT WEEK.
AVIATION /12Z TAFS THROUGH 12Z WEDNESDAY/
ISSUED AT 543 AM CDT TUE SEP 22 2026
MVFR CEILINGS BLANKET CENTRAL ILLINOIS EARLY THIS MORNING:
HOWEVER, DRIER BOUNDARY LAYER AIR AND HIGHER CEILINGS REMAIN
POISED JUST TO THE NORTHEAST AND WILL GRADUALLY FILTER INTO THE
AREA LATER THIS MORNING. CAMS APPEAR TO BE A LITTLE TOO
AGGRESSIVE WITH THE IMPROVING CEILINGS, SO HAVE DELAYED ONSET OF
VFR AT ALL SITES BY A COUPLE OF HOURS. AS A RESULT, HAVE RAISED
THE CLOUD DECK TO VFR AT THE I-74 TERMINALS BETWEEN 14Z AND 16Z,
THEN FURTHER S/SW TO KDEC/KSPI BY 17Z/18Z. CLOUDS WILL TEMPORARILY
SCATTER AT TIMES TODAY, BUT SKIES WILL GENERALLY REMAIN MOSTLY
CLOUDY. AFTER SUNSET, THE CONTINUED E/NE BOUNDARY LAYER FLOW
WILL LIKELY ALLOW LOW CLOUDS TO MAKE A RETURN FROM THE EAST.
HRRR/RAP SUGGEST CEILINGS LOWERING BACK TO MVFR AT KCMI BY
AROUND 00Z, THEN FURTHER WEST TO A KBMI TO KDEC LINE LATER IN
THE EVENING. WINDS WILL REMAIN NE AT 10-15KT THROUGH THE ENTIRE
12Z TAF PERIOD.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...BARNES
DISCUSSION...BARNES
AVIATION...BARNES
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