textproduct: Central Illinois

KEY MESSAGES

- Gusty winds tonight into Wednesday will promote near-record warmth through the middle of the week with daily temperatures in the upper 60s.

- Elevated fire concerns are possible on Wednesday, especially across west-central Illinois, due to the combination of warm, dry, and breezy conditions.

- Thursday brings an increased risk for severe weather. There is currently a Slight Risk (Level 2 of 5) in place for areas east of Interstate 55.

- Cooler weather returns this weekend with a low (20% or less) chance for 2 inches of snowfall.

DISCUSSION

Issued at 252 PM CST Tue Feb 17 2026

Our well-advertised warm-up will persist through the middle of this week. The pattern is being driven by a deep trough emerging from the eastern Pacific, which is spreading deep southwest flow across the intermountain west and the Plains states. As this trough moves rapidly eastward this evening and a surface lee cyclone strengthens, the Midwest will experience gusty southwest winds (30-45 mph) tonight through Wednesday morning. The net effect will be the warmest temperatures of the season so far. Current NBM median guidance strongly supports mid 60s Wednesday and Thursday, with the upper tail of guidance pushing 70 degrees each day. These April-like temperatures will be enough to chase the record books, and we have added a climate section below highlighting where the current records might be in peril.

A low risk for isolated damaging wind gusts exists later this evening behind a passing pre-frontal trough. Although limited moisture and poor thermodynamics in the developing warm sector will mute a broader severe weather risk, a few elevated convective showers could transfer momentum from a 50+ kt low-level jet (LLJ) down to the surface. Consequently, a Wind Advisory has been issued for this evening for areas generally east of the Illinois River Valley.

Both global deterministic guidance and some longer-range CAMs are indicating a favorable environment for severe weather on Thursday as another shortwave trough moves through the Upper- to Mid- Mississippi Valley. The highest probabilities for severe weather are centered near or just north of the confluence of the Mississippi and lower Ohio river valleys. In this area, boundary- layer moistening is expected to bring surface dewpoints into the mid-to-upper 50s and promote 500-1000 J/kg of SBCAPE across a broadening warm sector. The combination of strong deep-layer shear (60+ kts) and sufficient instability will be conducive to supercellular structures capable of producing all severe weather hazards Thursday afternoon across portions of central and southeast Illinois.

A shift to cooler weather is expected to return and persist from Friday through early next week. The NBM deterministic guidance suggests daily temperatures will remain slightly above normal on Friday and Saturday, with afternoon high temperatures around the middle 40s and overnight lows in the mid 20s.

The potential for accumulating snow on Saturday is increasing and requires close monitoring. A compact shortwave trough moving across the region is showing better support in recent model runs. NBM guidance now supports higher snow probabilities, suggesting adequate moisture depth and sub-freezing wet-bulb temperatures ahead of this system. While the chance of exceeding 2 inches of snow is currently low (20% or less), this remains a developing trend.

Temperatures then drop near normal for Sunday and Monday with highs near 40 degrees and lows near 20.

MJA

AVIATION

(For the 00z TAFs through 00z Wednesday Evening) Issued at 533 PM CST Tue Feb 17 2026

An active next 12 hours is in store as a frontal system approaches from the west bringing strong southerly winds gusting up to 35 kts, MVFR to IFR ceilings, and scattered showers (04-10Z) that may promote locally higher wind gusts. LLWS is borderline overnight with surface gusts remaining elevated. However, be aware that 2k ft winds may approach 50 kts between 03-09Z as a strong LLJ overspreads the region. A cold front will work through the area tomorrow morning, acting to scour out the low stratus and shift winds to the west-southwest. Wind speeds will remain breezy through the TAF period, though gusts should start to subside by late Wednesday afternoon into evening.

NMA

FIRE WEATHER

Issued at 252 PM CST Tue Feb 17 2026

Growing concern exists for elevated fire danger on Wednesday, a side effect of the unusually warm and breezy conditions. The primary risk area is anticipated to be for portions of west- central and northern Illinois, where rainfall has been particularly sparse over the last 30 days. This threat is expected to develop by late morning behind the surface front/dryline, with wind gusts gradually decreasing into the 20-30 mph range and relative humidity (RH) values dropping below 25%. A Fire Weather Watch has been issued for areas north of a Macomb to Kankakee line where wind gusts will be highest. Trends will be carefully monitored tonight for potential southward expansion.

MJA

CLIMATE

Issued at 252 PM CST Tue Feb 17 2026

Record high temperatures for Wednesday and Thursday:

Location Wednesday Thursday ======== ========= =========

CLIMATE

Issued at 252 PM CST Tue Feb 17 2026

Record high temperatures for Wednesday and Thursday:

Location Wednesday Thursday ======== ========= ========= Bloomington 72 (2017) 70 (1930) Champaign 70 (2017) 68 (2017) Charleston 68 (1961) 72 (1930) Decatur 70 (1911) 66 (1930) Lincoln 67 (2017) 71 (1930) Olney 72 (1961) 72 (1930) Peoria 68 (2017) 71 (1930) Springfield 68 (2017) 71 (2017)

Geelhart

ILX WATCHES/WARNINGS/ADVISORIES

Fire Weather Watch from Wednesday morning through Wednesday evening for ILZ027-028-030.

Wind Advisory until 1 AM CST Wednesday for ILZ031-037-038- 041>045-047-048-050>057-061>063.