160 FXUS63 KILX 281659 AFDILX Area Forecast Discussion...Updated Aviation National Weather Service Lincoln IL 1059 AM CST Sat Feb 28 2026 .KEY MESSAGES... - A period of light snow will occur Sunday night into early Monday morning...with the latest guidance showing a 20-40% chance of minor impacts south of the I-74 corridor. - Strong thunderstorms are possible Wednesday. The highest probability for severe weather (greater than a 15% chance) will focus further southwest across the Southern Plains. - Confidence is growing that beneficial rainfall will occur across all of central and southeast Illinois over the next week. The 00z Feb 28 LREF indicates a 50-70% chance of greater than 2 inches of rain from today through next Saturday morning. && .DISCUSSION... Issued at 354 AM CST Sat Feb 28 2026 ...Weather Synopsis... 09z/3am surface analysis shows a cold front dropping southward toward the Ohio River while a ridge of high pressure builds into the Northern Plains/Upper Midwest. Aloft...a deep low remains anchored over Hudson Bay with northwesterly flow around this feature from western Canada into the Midwest. Meanwhile another upper low is evident on water vapor imagery off the coast of California. ...Snow Sunday Night/Monday Morning... The cold front will continue to settle southward before becoming parallel with the upper flow and stalling in the Tennessee River Valley on Sunday. As a short-wave trough ejects eastward from the California upper low and interacts with the baroclinic zone, wintry precipitation will develop across Missouri on Sunday...then spread eastward across parts of central Illinois Sunday night into early Monday morning. Models continue to trend this system further south and weaker, with the 00z Feb 28 suite now suggesting locations along/north of I-74 may see little or no snow. The most recent Probabilistic Winter Storm Severity Index (PWSSI) from WPC shows a 20-40% chance of Minor Impacts south of the I-74 corridor...with higher probabilities focused further west across Missouri. Based on the southward shift in the wave track, the initially dry airmass, and limited deep-layer moisture, think snow accumulations of 1-2 inches will occur along/south of Macomb to Paris line...with less than 1 inch further north. While the snow will be light, snow-covered and slippery roads will be possible for the Monday morning commute. The light snow will change to rain, then taper off and/or come to an end Monday afternoon as high temperatures climb into the lower 40s. ...Strong Thunderstorms Wednesday... An active weather pattern will set up across the Midwest/Ohio River Valley next week as a series of waves interact with the stalled baroclinic zone within the W/SW upper flow regime. Models are suggesting a stronger wave and its associated surface low will track into the region on Wednesday. While the exact track of the low and its associated strong/severe weather risk remains somewhat in question, a clear signal for convection is developing. While the 00z ECMWF is slightly further south with its low track and is thus not as stormy, the GFS shows a 1010mb low lifting into west-central Illinois by 00z Thu. The atmosphere ahead of the low is progged to be modestly unstable (SBCAPE 400-600J/kg) and strongly sheared (0-6km bulk shear 50-60kt)...so the fuel for strong thunderstorms will be present. At this time, it appears the timing of the system may be a bit too slow to favor strong storms this far east...instead focusing the greatest risk further upstream across the Southern Plains during the day. The latest Colorado State Machine Learning algorithm indicates a 5-15% chance for severe across Illinois...but a 15-30% chance over parts of eastern Oklahoma/Kansas. Stay tuned for further details as the situation becomes clearer over the next few forecast cycles. ...Beneficial Rainfall Next Week... While the severe weather risk remains uncertain, confidence is growing that widespread beneficial rainfall will arrive across central Illinois next week. The synoptic pattern will feature favorable deep-layer W/SW flow, ample northward moisture transport from the Gulf, and a series of short-wave troughs interacting with a nearly stationary frontal boundary. The end result will be periods of showers and thunderstorms through the week. While model QPF fields vary, all solutions are pointing to much-needed rain across the entire region. It is still too early to pinpoint exact totals:however, the 00z LREF indicates a nearly 100% chance of greater than 1 inch across the entire KILX CWA through next Saturday morning...and a 50-70% of more than 2 inches. Barnes && .AVIATION... (For the 18z TAFs through 18z Sunday Afternoon) Issued at 1058 AM CST Sat Feb 28 2026 VFR conditions should continue through at least 06z. Winds will keep an easterly component through the period, and most commonly be out of the northeast. Winds become gusty this evening (around 20 kts) and remain so through the rest of the period. A few stray showers are possible at KSPI/KDEC this afternoon, but chances were too low to include in the TAF. Thunder is not expected. Low-level moisture from Lake Michigan could introduce some MVFR clouds late in the overnight/into Sunday morning, around 1500 feet, but the height of any low clouds that do form should quickly increase over the course of Sunday morning. Erwin && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$