946 FXUS63 KILX 021801 AFDILXArea Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 101 PM CDT Thu Oct 2 2025
.KEY MESSAGES...
- Above normal temperatures with highs in the mid 80s to near 90 degrees will continue through Monday over central/se IL, before an approaching cold front brings a return to more seasonable readings in the low to mid 70s on Wednesday and Thursday of next week.
- An elevated wildfire risk will develop this weekend over central IL especially by Sunday afternoon, as south to southwest winds increase to breezy levels. NBM has a 15-30% chance of wind gusts over 25 mph Sunday afternoon nw of the IL river.
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.DISCUSSION... Issued at 345 AM CDT Thu Oct 2 2025
The 08Z/3 am surface analysis shows expansive 1030-1034 mb Canadian high pressure over southeast Quebec and ridging sw across the Great Lakes and into WI and northern IL. A weak surface trof was just south of the Ohio river into eastern AR. Aloft strong 500 mb high was over northern Mexico and ridging ne over IN with 500 mb heights of 586-587 decameters over IL. IR Satellite imagery shows scattered to broken Cirrus stratus clouds over over all but far se and far nw IL and lifting ne. Temps at 330 am were in the mid 50s to lower 60s. Dewpoints ranged from the low to mid 40s from Lacon to BMI to Paris northeast while more moist dewpoints in the mid to upper 50s in southeast IL and from Macomb to Lincoln to Mattoon sw. Winds were light ENE to SE or calm over central/se IL. Latest CAMS show patchy fog developing in southern IL next few hours, possibly as far north as highway 50. Any fog the develops should dissipate by 8 am.
Strong Canadian high pressure to settle southward into the mid Atlantic States and ridging westward into the mid MS river valley on Friday and continue to ridge back over IL into this weekend. The upper level ridge to also stay over IL through this weekend and be strongest over IL on Friday with 500 mb heights approaching 588 decameters. This to continue the warm and dry wx pattern across the area through this weekend. Though a weak surface boundary near the Ohio river could develop isolated showers from mid afternoon into early evening in southern IL, but should stay south of Clay, Richland and Lawrence counties. Partly to mostly cloudy skies from cirrus clouds early this morning should trend partly mostly sunny this afternoon as these clouds decrease from the west. Very warm highs in the upper 80s today with mid 80s near the Indiana border where cirrus clouds hang on longer. South to SE winds generally under 10 mph today. Lows overnight in the lower 60s, with some upper 50s near the Indiana border around Vermilion and Edgar counties. Mostly sunny skies and sw winds under 10 mph on Friday with very warm highs in the upper 80s to around 90F but shy of record highs in the low to mid 90s.
A strong mid/upper level trof digging and moving eastward into the Western States late this week, to nudge the subtropical ridge over the Eastern States, east of IL. A frontal boundary to move se into the northern plains Friday night and Saturday and move se across Iowa during Sunday and Sunday night. Increase pressure gradient over central IL during this weekend especially by Sunday to increase south to sw winds to breezier levels over the IL river by Sat afternoon and over much of central IL by Sunday afternoon. Summerlike daytime temps linger through Monday with highs in the mid 80s to near 90F this weekend and in the mid 80s Monday.
Models have trended quicker with bringing 20-30% chance of showers and isolated thunderstorms into central and SE IL late Monday afternoon and Mon night, with 30-40% chance on Tue as cold front moves se into the area. Best chances shift into southeast IL during Tue night with CWA dry on Wed into Thu. Highs Tue in the lower 80s (upper 70s over IL river valley) cool into the low to mid 70s Wed/Thu as 1028-1030 mb high pressure settles into the Midwest and Great Lakes region.
Given the antecedent drought conditions over central and southeast IL, low fuel moisture and increasing winds...concern is growing for the potential for field fires over the weekend. While winds and minimum relative humidity values likely will not meet Red Flag criteria, burning is highly discouraged both Saturday and Sunday. The Hot-Dry-Windy Index (HDWI) using the GEFS, shows max daily values rising above the 75th percentile over the IL river valley Saturday afternoon, and over much of central IL especially from from Springfield to Paris north on Sunday afternoon (based on a 30-year climatology). We will likely be increasing our messaging for elevated fire danger as this weekend approaches.
The Climate Prediction Center (CPC) 8-14 Day Outlook for Oct 9-15th has a 50-60% chance of above normal temperatures over IL and a 35-40% chance of above normal precipitation over central/se IL. The drought may likely persist or even intensify over central and southeast during the next two weeks. On a plus side, the growing season looks to continue over the area through at least Oct 15th with the coolest lows in the 40s from middle of next week (Wed night) and on.
07
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.AVIATION... (For the 18z TAFs through 18z Friday Afternoon) Issued at 1204 PM CDT Thu Oct 2 2025
Ridge of high pressure will continue to inch east across the region resulting in fair weather over central Illinois. South winds today and tonight will veer to the southwest Friday. Some scattered to broken high based cumulus is expected by Friday late morning or afternoon.
Deubelbeiss
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.ILX WATCHES/WARNINGS/ADVISORIES... None. &&
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NWS ILX Office Area Forecast Discussion