textproduct: Central Illinois

KEY MESSAGES

- Southerly winds strengthen this afternoon with a 70-90% chance of wind gusts greater than 40 mph from 6pm to 3am tonight across central and southeastern IL.

- April-like warmth, with daily temperatures in the 60s, is forecast through Thursday. Elevated fire concerns are possible by Wednesday afternoon, especially across west-central IL, due to the combination of warm and breezy conditions.

- There is a slight risk (level 2 of 5) for severe weather on Thursday for areas east, southeast of a Jacksonville to Bloomington line. Primary hazards are tornadoes and damaging winds, but small hail is also possible.

DISCUSSION

Issued at 246 AM CST Tue Feb 17 2026

Record warmth occurred yesterday, and we will be flirting with more potential record highs through Thursday. Highs in the 60s for the next few days, nearing 70 in some locations Wednesday and Thursday. Lows tonight in the upper 40s to low 50s will be pleasant. Then lows will become cooler through the rest of the week. After the cold front on Thursday, temperatures cool to more seasonable levels for the end of the week, with highs in the upper 30s to mid 40s and lows in the upper teens to upper 20s.

Southerly winds strengthen today ahead of system #1 of the week as the pressure gradient tightens ahead of the train of systems. Winds will gust to 30-40 mph today based off HRRR, NAMNest, and HREF. The HREF is showing a 70-90% chance of wind gusts greater than 40 mph from 00z this evening to 09z tonight. Winds will lighten after 12z tomorrow morning to closer to 20 mph gusts for Wednesday. By Wednesday evening, winds will relax even more out of the southwest as the second low system approaches Illinois.

Elevated fire danger is possible tomorrow, driven by the unusually warm and breezy conditions. The primary risk area will likely be west-central Illinois, which has seen particularly sparse rainfall over the last 30 days. This threat is expected in the afternoon, with minimum RH values dropping below 30% as wind gusts gradually decrease.

The series of low pressure systems is still forecast to impact central IL this week. The first arriving tonight into Wednesday morning bringing a 20-50% chance for some rain, focused north of I- 70, as a low passes off to the north of IL with a cold front swooping through central and southeastern IL. Models are still showing very minimal precipitation coverage with this round. Thunderstorms look unlikely as the cold front moves through. Rainfall amounts continue to look pretty minimal (< 0.1 inch) this forecast cycle, with the measurable amounts mainly north of I-72.

The second system will pack more of a punch and is expected Thursday into Friday. This system will bring 40-60% chance for rain and thunderstorms to central and southeastern IL. CAMs are still just out of reach for this event as of this morning. However by this afternoon, we should start to see a more detailed picture of the evolution of the system. It looks like the area to watch for severe weather is east of I-55, chances improving as you approach the Indiana border and I-70 corridor. A coarse look at the storm type shows potential for supercellular activity. Taking a gander at the environmental factors for Thursday afternoon, MUCAPE/SBCAPE values of 700-1000 J/kg and bulk wind shear of 60-80 knots are forecast, making this a high shear/low CAPE set up. There is ~500 J/kg of DCAPE on the forecast soundings. The primary hazard of concern at this time is the tornado and damaging winds potential. Small hail may fall but the ingredients aren't screaming hail potential right now. SPC has a D3 slight risk (level 2 of 5) for areas east, southeast of a Jacksonville to Bloomington line.

There is a third system now for the weekend (Saturday into Sunday) that could bring some rain, snow, and maybe a mix to central and southeastern IL. Snow amounts look to be minimal, just a dusting. We need to get through the first two systems, so we will continue to monitor this development as the week continues.

Copple

AVIATION

(For the 18z TAFs through 18z Wednesday Afternoon) Issued at 1131 AM CST Tue Feb 17 2026

Surface winds will increase later this evening as a frontal system lifts across the Upper Midwest. Occasional gusts between 25-35 kts are likely, and may be accompanied by scattered showers which could promote locally higher wind gusts exceeding 40 kts.

Ceilings are forecast to gradually lower into the MVFR range between 00z-06z as showery activity develops ahead of the cold front, then gradually return to VFR between 09z-13z as the front pushes past the regional terminals.

Winds will shift from southwest to west Wednesday morning as the cold front departs the region. Skies will then quickly clear and winds will become more muted by the end of the TAF period.

MJA

ILX WATCHES/WARNINGS/ADVISORIES

None.