textproduct: Central Illinois

KEY MESSAGES

- Above normal temperatures will kick off the work week, with highs generally in the upper 40s to mid 50s Monday and Tuesday. Temperatures will trend closer to normal Wednesday through Friday.

- Rain chances have decreased considerably with the midweek system. There is now an 80-95% (highest north) chance conditions remain dry.

- Higher (30-40%) precipitation chances will exist late Thursday and again on Saturday. With diurnal temperature swings crossing the freezing mark each day, some of this may fall as a wintry mix.

DISCUSSION

Issued at 119 AM CST Sun Feb 8 2026

***** INCREASINGLY MILD INTO TUESDAY *****

At 1am, upper level ridging was expanding into the Midwest ahead of a weak shortwave trough which will pass from the Central Plains into the Deep South tonight into tomorrow morning. At the surface, a west- east pressure gradient resulting from a high centered in the Ohio Valley was fostering gentle southeast winds which, combined with mid level cloud cover, should hold temperatures in the 20s for most of the area through dawn.

HREF/NBM indicate our cloud cover will likely (70-90% chance) clear out from west to east from late morning to mid afternoon, causing a gradient in high temperatures which will run from the low 30s in east-central IL to low 40s in west-central IL. This is near normal for early February, though it will feel about 10 degrees cooler due to southeast winds around 10-15 (gusting 20+) mph.

The area will receive a better push of warm advection on Monday ahead of a surface low tracking from the Upper Midwest into the Great Lakes, with LREF mean bringing 850mb temps (500mb heights) into the 10-12 degC (565-570 dam) range. This will give areas west of a Peoria to Springfield line a 30-40% chance of hitting 50, while once again temperatures run cooler towards the east (i.e., low-mid 40s east of I-57). Temperatures are a bit more uncertain on Tuesday as a decaying cold front sweeps through the area in the morning. The precise timing and strength of this front (plus cloud cover) will dictate how much we warm, but NBM still advertises a 50-70% chance daily highs climb into the 50s southwest of a Macomb to Terre Haute line.

***** A FEW PRECIP CHANCES LATE WEEK *****

The aforementioned front should have a dry passage early Tuesday, while a southern stream disturbance, which was initially slated to graze our southern counties, passes entirely to our south Tuesday night. Consequently, rain chances have decreased yet again from the previous forecast package; NBM now gives only 10-20% chances for rain south of a Pana to Casey line (less than 10% further north).

Central IL remains in close proximity of the polar jet the remainder of the week, favoring one or more opportunities for precipitation. Global models and their respective ensembles seem to be slowly narrowing down two primary shots at precip: one with a northern stream shortwave late Thursday into early Friday, and another if phasing occurs with the sub-tropical jet on Saturday. Because the latter solution, depicted by the GFS and about 60% of LREF members, would involve better moisture transport into the region from the Gulf, it has the highest potential of bringing our area over an inch of precip (20%, vs 5% with the Thursday system, according to NBM). This will bear watching for nuisance flooding given our 11" frost depth, though the top couple inches will likely thaw by then, which should allow some absorption by the soil. P-types are uncertain with both systems, but the first seems to stand the highest (~30%) chance of giving part of the area a band of accumulating snow. Model spread in temperatures increases late in the week; for example, the interquartile range (IQR) spans 37-49 degF in Lincoln for Saturday's highs - meaning there's an equal chance max temps that day fall inside or outside those values. Nonetheless, the general trend is upward, with a strong signal for more pronounced warming heading into the week of 2/15.

Bumgardner

AVIATION

(For the 12z TAFs through 12z Monday Morning) Issued at 525 AM CST Sun Feb 8 2026

As a mid level disturbance crosses the area, varying degrees of VFR cloudiness will continue through the forecast period. Southeast winds will increase to 13-17 kt mid morning, with sporadic gusts topping 20 kt until the surface pressure gradient relaxes after 23z/5pm.

Bumgardner

ILX WATCHES/WARNINGS/ADVISORIES

None.