878
FXUS63 KILX 211844
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
144 PM CDT MON SEP 21 2026
KEY MESSAGES
- COOLER WEATHER WILL PREVAIL THIS WEEK AS HIGH TEMPERATURES
RANGE FROM THE 60S TO 70S.
DISCUSSION
ISSUED AT 144 PM CDT MON SEP 21 2026
WATER VAPOR IMAGERY EARLY THIS AFTERNOON SHOWS AN UPPER LOW SPINNING
OVER EASTERN NEBRASKA/WESTERN IOWA WITH RIDGING ON BOTH SIDES OF IT.
AT THE SURFACE, A COLD/STATIONARY FRONT IS DRAPED FROM THE MID-
ATLANTIC STATES WESTWARD INTO ARKANSAS WITH HIGH PRESSURE CENTERED
OVER ONTARIO. WIDESPREAD CLOUD COVER WILL REMAIN IN PLACE THROUGH AT
LEAST TUESDAY MORNING AS LOW-LEVEL MOISTURE REMAINS TRAPPED BENEATH
A TEMPERATURE INVERSION, HOLDING TEMPERATURES SEVERAL DEGREES COOLER
THAN NORMAL.
SPOTTY SHOWERS/DRIZZLE ARE NOTED ON REGIONAL RADAR WITHIN THE
VICINITY OF THE AFOREMENTIONED UPPER LOW FROM CENTRAL IOWA INTO
NORTHWEST ILLINOIS, AND ALSO DOWNWIND OF LAKE MICHIGAN WHERE STEADY
NORTHEAST WINDS ARE SPREADING MOISTURE INLAND. SIMILAR CONDITIONS
ARE EXPECTED TO EXPAND EAST THROUGH TUESDAY MORNING AS THE UPPER LOW
POSITIONS ITSELF OVER EASTERN IOWA/NORTHWEST ILLINOIS BY DAYBREAK.
THESE SHOULD BE VERY LIGHT IN NATURE AND AMOUNT TO LITTLE
ACCUMULATION. TEMPERATURES ON TUESDAY WILL BE SIMILAR TO TODAY DUE
TO WIDESPREAD CLOUD COVER/PRECIPITATION WITH OVERNIGHT LOWS
DROPPING INTO THE LOW TO MIDDLE 50S. SUBSIDENCE ON THE BACKSIDE
OF THE UPPER LOW SHOULD RESULT IN SOME POCKETS OF CLEARING
ACROSS WEST- CENTRAL ILLINOIS TUESDAY NIGHT, POTENTIALLY OPENING
THE DOOR FOR A FEW SPOTS TO DIP DOWN INTO THE UPPER 40S (20-40%
CHANCE).
BY MIDWEEK, THE UPPER LOW MEANDERS INTO THE MID-ATLANTIC STATES WITH
SUBTLE RIDGING BUILDING IN ITS WAKE. TEMPERATURES WILL REMAIN COOL
THROUGH THE END OF THE WEEK, THEN GRADUALLY WARM BACK INTO THE 70S
TO LOW 80S BY THE LATTER HALF OF THE WEEKEND. PRECIPITATION CHANCES
LOOK MINIMAL MIDWEEK THROUGH THE WEEKEND, THOUGH A DEVELOPING LOW
OVER THE PLAINS STATES MAY BEGIN TO ENCROACH ON THE MIDWEST STATES
LATER THIS WEEKEND.
AVIATION /18Z TAFS THROUGH 18Z TUESDAY/
ISSUED AT 1216 PM CDT MON SEP 21 2026
PESKY MVFR TO OCCASIONALLY IFR LOW STRATUS WILL LINGER THROUGH A
MAJORITY OF THE TAF PERIOD. SHORT TERM MODELS DIFFER ON LATE
PERIOD IMPROVEMENT, WITH SOME OF THE MORE OPTIMISTIC GUIDANCE
SHOWING CEILINGS RETURNING BACK TO VFR BY MID TO LATE MORNING.
SPOTTY SHOWERS OR DRIZZLE MAY BRING VISBYS DOWN BRIEFLY BETWEEN
3-5SM, BUT THOSE SHOULD LARGELY REMAIN VFR. WINDS WILL REMAIN
STEADY OUT OF THE NORTHEAST WITH SPEEDS AROUND 12 KTS OR LESS.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...NMA
DISCUSSION...NMA
AVIATION...NMA
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