485 FXUS63 KILX 291650 AFDILXArea Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1150 AM CDT Mon Sep 29 2025
.KEY MESSAGES...
- A long stretch of dry weather will likely continue through this weekend across central and southeast IL. This will lead to worsening drought impacts, and an increased risk of field fires during the peak harvest season underway.
- Unseasonably warm daytime highs near 90 again today, upper 80s to near 90 Tuesday, and mid to upper 80s the rest of the week. Lows will be mainly in the 50s and lower 60s. Winds to remain fairly light under 10 mph through Friday, with a bit stronger south southwest winds this weekend.
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.DISCUSSION... Issued at 340 AM CDT Mon Sep 29 2025
The 08Z/3 am surface map shows a 1022 mb high pressure over Lake Huron and ridging sw across central parts of IL and MO. A very weak and dissipating boundary was near I-74. Winds were light to calm once again across the area. Very patchy shallow/ground fog noted near the Indiana border and southern IL from I-64 south. Temperatures were in the mid 50s to lower 60s. Aloft a large subtropical ridge was over the central and eastern US with a 590 dm 500 mb high over central/nw IL. We continue to be a blocky weather pattern with IL stay high and dry with very warm highs and large 30-40 degree diurnal temperature swings in very dry air mass locked in place.
The patchy shallow/ground fog mainly near rivers/waterways and in low lying farm fields (especially those that had heavier rainfall earlier last week) should lift quickly by 8 am. Otherwise another sunny day with hot temperatures this afternoon as highs reach near 90. Will be well shy of record highs around 100 today which were set in 1953. Winds to trend east to NE during today and staying fairly light, under 10 mph. Clear skies tonight with light winds and lows in the upper 50s to around 60F. Could see patchy shallow ground fog later tonight/early Tue morning near rivers/waterways and low lying fields, with CAMS showing better chance of patchy fog closer to Lake MI/Chicago area.
A stronger 1032-1034 mb Canadian high pressure to track over northern Ontario and James Bay on Tue and pushing se into New England and the mid Atlantic States Thu/Friday. Meanwhile a 500 mb high to stay over IL during rest of the week with 500 mb heights of 586-588 decameters. So dry pattern to continue rest of the week. NE winds will increase a bit on Tue to 6-12 mph by Tue afternoon with a little more cumulus clouds over the IL river valley Tue afternoon but still mostly sunny. Still very warm Tue with highs in the upper 80s and a few areas from Peoria and Springfield west approaching 90 again. Still shy of record highs in the low to mid 90s on Tue. Clouds continue to increase some during Tue night as skies become partly cloudy. Lows Tue night 55-60F, coolest in east central IL. Partly sunny skies Wed with highs mostly in the mid 80s with ENE winds 5-10 mph. Clouds decrease from the west during Thu with warm highs in the mid 80s (upper 80s possible over the IL river valley where more sunshine expected).
Upper level trof off the West Coast to dig into the Western States late this week with strong upper level ridging holding over the eastern half of the US including IL. Some energy ejecting ne into the upper Midwest during this weekend while frontal boundary stays north and nw of IL along with rain chances staying nw of CWA through next Monday. Warm highs in the mid to upper 80s Fri/Sat, mid 80s Sunday and low to mid 80s next Monday.
The Climate Prediction Center (CPC) 6-10 Day outlook for Oct 4-8th has a 80-90% chance of above normal temperatures over central IL and 75-80% chance of above normal temps in southern/southeast IL. Precipitation is trending 33-40% chance below normal east of I-55 and near normal west of I-55, with nw IL having 33-40% chance of above normal pcpn. CPC 8-14 Day Outlook for Oct 6-12th has 60-70% chance of above normal temperatures over IL. Precipitation is trending near normal over southern half of IL and 33-40% chance of above normal pcpn over northern half of IL. Highs in the 80s look prevalent over CWA through Tue/Oct 7th.
07
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.AVIATION... (For the 18z TAFs through 18z Tuesday Afternoon) Issued at 1150 AM CDT Mon Sep 29 2025
Mainly clear skies with a few diurnal cu through midday Tuesday. Light/variable winds will trend light northeast this afternoon and again on Tuesday.
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.CLIMATE... Issued at 600 PM CDT Sun Sep 28 2025
Record high temperatures through Wednesday:
Location Monday Tuesday Wednesday -------- ---------- ---------- --------- Bloomington 100 (1953) 98 (1953) 92 (1897) Champaign 99 (1953) 91 (1971) 92 (1897) Charleston 99 (1953) 92 (1933) 94 (2019) Decatur 100 (1953) 94 (1922) 93 (1897) Lincoln 101 (1953) 93 (1952) 91 (2019) Olney 101 (1953) 93 (1952) 94 (1952) Peoria 98 (1953) 91 (1933) 89 (1937) Springfield 100 (1953) 92 (1971) 91 (2019)
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.ILX WATCHES/WARNINGS/ADVISORIES... None. &&
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NWS ILX Office Area Forecast Discussion