textproduct: Central Illinois

KEY MESSAGES

- Dry fuels and low relative humidity will lead to an elevated risk for afternoon agricultural field fires today, Thursday, Friday, and Saturday, especially southeast of the IL River.

- The next notable chance for rain is Saturday night into Sunday especially over east central and southeast IL. LREF has a 30-45% chance for more than a half inch of rain along and southeast of a Terre Haute to Flora line.

DISCUSSION

Issued at 330 AM CDT Wed Oct 7 2026

The 08Z/3 am surface map shows 1020 mb high pressure over the mid Atlantic States and ridging sw into the mid MS river valley. A cold front was over southeast WI, central IA into southeast Nebraska. Clear skies prevailed over IL with light southwest winds over central IL and calm winds in southeast IL. Temps were in the 50s over much of CWA with some mid to upper 40s in southeast IL.

The latest CAMs push cold front se through the IL river valley late this morning, thru rest of central IL during this afternoon and thru se IL early this evening. Little lift and moisture with this front and should pass thru dry with a fair amount of sunshine again with some high clouds sweeping by. SW winds 5-15 mph to shift nw after cold front passes through. Warm highs in the low to mid 80s, warmest from I-72 south. This is above normal highs in the lower 70s but shy of record highs near 90F today. Fair skies expected tonight with lows in the lower 50s (which is close to normal lows in the upper 40s).

Weak 1020 mb high pressure to settle southeast into Iowa by midday Thu and provide plenty of sunshine again with nw winds 5-10 mph. Overall a pretty nice day with highs in the mid to upper 70s central IL and lower 80s in southeast IL. High pressure drifts into the eastern Ohio river valley and central Appalachians by dawn Friday, while a weak short wave moves into Iowa and nw IL overnight Thu night. Most of its light showers should be nw of central IL overnight Thu night into Friday morning as our air mass it pretty dry, and we just have slight pops north/nw of Peoria late Thu night into Fri morning. Lows Thu night in the lower 50s, with some upper 40s in east central IL. High pressure over the Eastern Great Lakes and mid Atlantic States by Friday afternoon gives a SSE winds of 7-14 mph. Upper level ridge builds over IL on Friday with 500 mb heights around 585 decameters by days end. Some clouds over central IL Fri morning especially northern half to give way to more sunshine Fri afternoon with warmer highs in the lower 80s (mid 80s from Springfield sw). Another warm day in the 80s expected Sat as mid/high clouds increase from the south during Saturday afternoon.

Our forecast Sat night into Sunday will depend on track of a tropical system currently Tropical Depression Nine over the southwestern Gulf of America. The National Hurricane Center (NHC) has it becoming a tropical storm Isaias early this morning and lifting northeast into the central Gulf by sunset Thu when it is forecast to become the 1st hurricane in the Atlantic basin this year. Isaias is forecast to turn north and reach near the AL/MS gulf coast during Fri evening, with its remnants moving into the lower Ohio river valley on Sunday. ECMWF and GFS models bring widespread showers NNE over central and se IL during Sat night into Sunday morning while GEM model keeping qpf further south/se of central IL and mainly clipping southeast IL with some showers on Sunday. Blended models show highest pops overnight Sat night and Sunday morning over east central and se IL where pops peak from 40-60% from I-57 east. The LREF has a 30-45% chance of over a half inch of rain Sat night into Sunday along and southeast of a Terre Haute to Flora line where isolated thunderstorms possible. Shower chances to diminish during Sunday afternoon over eastern IL. Highs Sunday to be much cooler mid 70s in southeast IL and possibly cooler near the Wabash river. Highs around 80F from I-55 west.

Some upper level ridging back into central/se IL on Monday with dry and warm conditions with highs in the lower 80s, with mid 80s possible from Springfield sw. A northern stream short wave trof tracking eastward over the upper Midwest and into the Great Lakes late Monday and Monday night, with cold front pushing se over area during monday night. NBM has 20-30% chance of showers northern CWA Mon evening and across CWA overnight Mon night into Tue with higher chances of rain and moderate qpf north and ne of CWA. Temps to cool for mid week, getting closer to normal by next Wed with highs in the upper 60s/lower 70s.

AVIATION /12Z TAFS THROUGH 12Z THURSDAY/

Issued at 530 AM CDT Wed Oct 7 2026

A weak cold front approaching the IA/IL border early this morning, will push se across central Illinois around midday. Southwest winds 5-10 kts ahead of the front will veer to west then northwest with its passage. Winds will pick up to around 10 kts with gusts 15-20 kts from 17-22Z. No precipitation or fog is expected and VFR conditions will prevail through the period with just few to scattered cirrus clouds later this morning and afternoon.

ILX WATCHES/WARNINGS/ADVISORIES

None.