textproduct: Central Illinois

KEY MESSAGES

- A few lingering light rain showers mixed with some snowflakes over east central IL will dissipate around sunset.

- Below normal temperatures will prevail through this weekend, with temperatures gradually warming back above normal during middle and later part of next week.

DISCUSSION

Issued at 240 PM CST Fri Nov 13 2026

A large slow moving upper level low over the upper Ohio river valley (535 decameter 500 mb low nw PA), has a strong short wave trof extending westward into southern WI and northern IL. This short wave trof was still producing isolated south bound light rain showers in east central IL mixed at times with light snow like recently at BMI. But trends have been diminishing and HRRR and RRFS models dissipate these by sunset. Nearly overcast low clouds over east central and southeast IL and from Jacksonville sw while scattered to broken diurnally driven cu/stratocumulus clouds over the IL river valley early this afternoon. Drier air working in from the NNW will see these clouds decrease from the north into this evening, lingering longest over Vermilion county where a north/south oriented lake enhanced band of rain/snow showers will be closest to. With clouds and North to NW winds decreasing this evening, expect a our 1st widespread hard freeze over CWA overnight with lows in the mid to upper 20s.

Some low clouds may linger over Vermilion and Edgar counties Saturday, otherwise much of CWA will enjoy ample sunshine Saturday with lighter northwest winds as high pressure over MN/IA settles closer to IL. Another hard freeze likely Sat night with high pressure nearby with clear skies and light to calm winds, with lows in the mid 20s. High pressure to be over IL on Sunday with sunny skies and light/calm winds with highs in the lower 50s, and lows in the upper 20s Sunday night. High pressure slowly moves away from IL across the Ohio river valley on Monday and into the central Appalachians Tue and continues a fair amount of sunshine with highs in the low to mid 50s Monday and mid to upper 50s Tue.

Upper level ridge will shift into the Southeast States with deepening upper level trof into the Western States Wed-Fri with IL getting in a more unsettled SW upper level flow. Large surface high pressure ridge over the mid Atlantic States Wed and Wed night should still keep IL dry with SSE flow starting a warm up. Highs Wed in the upper 50s/lower 60s climb into the mid 60s to near 70F next Friday and Saturday (Nov 20-21). A weak disturbance ejecting ne into MO/IL Thu could bring next chance of rain showers, especially over the IL river valley. A stronger system looks to arrive next weekend bringing in a better chance of convection.

The Climate Prediction Center (CPC) 8-14 Day Outlook for Nov 21-27th has a 50-55% chance of above normal temperatures over central and southeast IL, and 35-40% chance of above normal precipitation. So not very good chances of accumulating snows over the area during the next two weeks. CPC Week 3-4 Outlook for Nov 28-Dec 11 (just released) has a 40-45% chance of above normal temperatures over CWA, and 33-40% chance above normal precipitation over central/southern IL and equal chances above and below normal precipitation over northern third of IL.

AVIATION /00Z TAFS THROUGH 00Z SUNDAY/

Issued at 521 PM CST Fri Nov 13 2026

VFR conditions will prevail the next 24 hours, with periodic ceilings around 4-5kft through much of the night. Channel of MVFR ceilings/visibilities associated with the moisture plume off Lake Michigan should stay east of KCMI. North/northwest winds are settling down slowly, and should be in the 5-7 knot range by mid evening.

ILX WATCHES/WARNINGS/ADVISORIES

None.