textproduct: Central Illinois

KEY MESSAGES

- Mild conditions will kick off the work week with highs in the mid 40s to low 50s today and tomorrow. Temperatures will trend near to slightly above normal the remainder of the week.

- There is a 40-50% chance of precipitation Thursday night. With temperatures dipping below freezing, some of this may fall as a wintry mix or snow.

DISCUSSION

Issued at 111 AM CST Mon Feb 9 2026

***** TODAY AND TOMORROW *****

At 1am, mid level water vapor satellite revealed a shortwave trough in southwest Missouri, with ridging across the Upper Midwest. As this ridge expands eastward into our area today, it will flatten some in response to a shortwave ejecting from the Intermountain West into the Great Lakes. Nevertheless, low level southerly flow ahead of a lee cyclone will bring a seasonably mild airmass into the region resulting in afternoon highs in the low 40s in east-central IL to around 50 in west-central IL. As that surface low pulls off to the north, the cold front will decay as it sags southward into our area tomorrow morning. Despite the weak cool advection in its wake, highs should approach 50 area-wide, with locations south of a Beardstown to Terre Haute line perhaps (NBM gives a 50-70% chance) exceeding 50.

***** WINTRY MIX THURSDAY NIGHT? *****

Limited moisture return ahead of the aforementioned front will prevent precip, with an even drier airmass entering the region in its wake. As surface high pressure settles into the area favoring light winds, a bit of sunshine could make for a pleasant Wednesday afternoon, with NBM giving a 40-70% chance (highest west) for highs over 45. Ahead of a shortwave disturbance, cloudiness will increase over the area on Thursday, resulting in slightly (3-5 degF) cooler temperatures. In addition, a portion of the area may see some precipitation; NBM probabilities have shifted southwest where the deterministic models are advertising better forcing. In fact, the 09.00z GFS depicts some saturated equivalent potential vorticity above and on the immediate warm side of a relatively pronounced FGEN band, indicating CSI and potential for some accumulating snow - especially considering the nocturnal timing (Thursday night). Time heights suggests the duration of this overlap in DGZ saturation and lift will be brief, with dry mid level air causing precip to change over to sleet or freezing drizzle before surface temps warm above freezing on Friday. Nonetheless, a quick couple inches in a band of snow wouldn't surprise us; NBM/LREF suggest the probability of more than 2 inches in any given location is only 5-15% at this time.

***** ANOTHER CHANCE FOR PRECIP ON SATURDAY *****

The second shot at precipitation will be Saturday into Saturday night as a southern stream disturbance phases with the polar jet somewhere across the Mississippi or Ohio Valley. NBM continues to paint our forecast area with 40-50% precipitation chances, with even a 10-25% (highest south) chance for more than an inch of rain by Sunday morning. This will ultimately come down to if and where phasing occurs, with better chances for beneficial precipitation in a scenario with phasing over or upstream of our area vs one where the phasing occurs to our southeast. Temperatures will be influenced by the track of that feature, so there is a bit of spread with the middle 50% of guidance giving highs anywhere from the upper 30s to upper 40s on Saturday, and low 40s to low 50s Sunday.

Bumgardner

AVIATION

(For the 12z TAFs through 12z Tuesday Morning) Issued at 528 AM CST Mon Feb 9 2026

High clouds will increase today ahead of a disturbance which will push a cold front through the area near/after the end of the forecast period. Winds will veer from easterly this morning to southerly by afternoon, with speeds generally remaining 10 kt or less until late this evening when a low level jet will result in LLWS. Most models suggest VFR conditions should prevail the entire forecast period, but the HREF suggests chances are as high as 30-40% for IFR ceilings with moisture advection after 09z (3am) Tuesday ahead of the cold front.

Bumgardner

ILX WATCHES/WARNINGS/ADVISORIES

None.