051
FXUS63 KILX 181723
AFDILX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE LINCOLN IL
1223 PM CDT SUN OCT 18 2026
KEY MESSAGES
- FROST WILL BE LIKELY ACROSS AREAS GENERALLY EAST OF THE IL
RIVER THROUGH 9 AM AS TEMPERATURES DIP INTO THE LOW TO MID 30S
BY DAWN. A FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM CDT
FROM MCLEAN, LOGAN AND SANGAMON COUNTIES EAST. PATCHY FROST IS
POSSIBLY IN EASTERN IL OVERNIGHT AND EARLY MONDAY MORNING WITH
LOWS IN THE MID TO UPPER 30S.
- TEMPERATURES WILL BEGIN A WARMING TREND THIS WEEK. HIGHS TODAY
IN THE MID TO UPPER 60S, WILL CLIMB INTO THE MID 70S TO LOWER
80S FROM THURSDAY INTO NEXT WEEKEND.
DISCUSSION
ISSUED AT 300 AM CDT SUN OCT 18 2026
THE 08Z/3 AM SURFACE ANALYSIS SHOWS 1035 MB HIGH PRESSURE OVER
THE UPPER OHIO RIVER VALLEY (SOUTHEAST OHIO, WESTERN PA AND
NORTHERN WV) AND RIDGING SW INTO THE MID MS RIVER VALLEY
INCLUDING SOUTHEAST IL. NEARBY HIGH PRESSURE RIDGE PROVIDING
CLEAR SKIES ACROSS IL, WITH LIGHT SOUTH TO SE WINDS IN CENTRAL
IL AND NEAR CALM WINDS IN SOUTHEAST IL. TEMPERATURES WERE IN THE
MID 30S TO AROUND 40F AT 3 AM, WITH ROBINSON, MARSHALL AND PARIS
CLOSE TO FREEZING. DEWPOINTS WERE IN THE LOW TO MID 30S AND
THIS IS HOW COOL SOME AREAS WILL LIKELY GET BY DAWN EAST OF THE
IL RIVER VALLEY. WILL CONTINUE THE FROST ADVISORY UNTIL 9 AM FOR
CENTRAL/EASTERN CWA FROM MCLEAN, LOGAN AND SANGAMON COUNTIES
EAST WHERE FROST WILL BE MORE WIDESPREAD, WHILE PATCHY FROST
OVER THE IL RIVER VALLEY.
HIGH PRESSURE TO SETTLE OVER NEW ENGLAND AND THE MID ATLANTIC
STATES BY SUNSET AND CONTINUE TO RIDGE BACK INTO IL THROUGH
MONDAY. SOUTHERLY WINDS INCREASE SOME TODAY ESPECIALLY
NORTHERN/NW CWA WITH GUSTS 15-20 MPH BY AFTERNOON. AMPLE
SUNSHINE TODAY WITH NEARBY SURFACE HIGH PRESSURE ALONG WITH
MID/UPPER LEVEL RIDGE OVER IL (500 MB HEIGHTS OVER 585
DECAMETERS). MILDER AND SEASONABLE HIGHS IN THE MID TO UPPER
60S. SEASONABLY COOL NIGHT AHEAD TONIGHT WITH LOWS IN THE UPPER
30S TO AROUND 40F, WITH MID 30S POSSIBLE NEAR THE IN BORDER.
PATCHY FROST POSSIBLE IN EASTERN IL LATER TONIGHT AND EARLY MON
MORNING, THOUGH LESS COVERAGE THAN EARLY THIS MORNING.
HIGH/CIRRUS CLOUDS TO INCREASE FROM THE WEST LATE MON MORNING
INTO MONDAY AFTERNOON, THOUGH STILL A FAIR AMOUNT OF SUNSHINE.
DRY ATMOSPHERE CONTINUES TO MODIFY WITH HIGHS MONDAY IN THE
UPPER 60S AND LOWER 70S. LOWS MON NIGHT IN THE UPPER 30S AND
LOWER 40S, COOLEST IN EASTERN IL.
ANOTHER LARGE HIGH PRESSURE SYSTEM MOVES EASTWARD FROM ONTARIO
ACROSS QUEBEC PROVINCE ON TUE/WED WHILE RIDGING INTO IL AND
CONTINUES FAIR/DRY WEATHER. HIGHS 70-75F ON TUE AND A FEW
DEGREES WARMER WED, IN THE MID 70S. LOWS TUE NIGHT IN THE LOW TO
MID 40S, COOLEST IN EASTERN IL AGAIN. YET ANOTHER HIGH PRESSURE
SYSTEM MOVES EASTWARD OVER THE NORTHERN GREAT LAKES THU AND
INTO SOUTHEAST CANADA AND NEW ENGLAND LATE THIS WEEK WHILE
RIDGING TOWARD IL. MEANWHILE HAVE STRONG MID/UPPER LEVEL RIDGE
BUILDING OVER IL LATE THIS WEEK. THESE TWO FEATURES TO ENSURE
DRY WEATHER WITH WARMER TEMPERATURES WITH HIGHS IN THE MID 70S
TO LOWER 80S FROM THU THROUGH NEXT SUNDAY.
THE CLIMATE PREDICTION CENTER (CPC) 6-10 DAY OUTLOOK FOR OCT
23-27TH HAS A 65-75% CHANCE OF ABOVE NORMAL TEMPERATURES OVER
CENTRAL AND SOUTHEAST IL, WITH A 40-50% CHANCE OF BELOW NORMAL
PRECIPITATION. THIS BODES WELL FOR THE FALL HARVESTING WHICH IS
MORE THAN HALF WAY COMPLETE OVER ILLINOIS. CPC 8-14 DAY OUTLOOK
FOR OCT 25-31ST HAS A 60-70% CHANCE OF ABOVE NORMAL TEMPERATURES
AND PRECIPITATION TRENDING NEAR NORMAL, EXCEPT TRENDING
SLIGHTLY BELOW NORMAL (33-40%) NEAR THE INDIANA BORDER.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1223 PM CDT SUN OCT 18 2026
VFR CONDITIONS WILL PREVAIL AT ALL TAF SITES NEXT 24HRS WITH
CLEAR SKIES EXPECTED. WINDS WILL BE SOUTH AT AROUND 10-15 KTS.
LIGHT AND VARIABLE RETURN FOR THE EVENING HOURS.
ILX WATCHES/WARNINGS/ADVISORIES
NONE.
KEY MESSAGES...07
DISCUSSION...07
AVIATION...COPPLE
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