Area Forecast Discussion
Issued by NWS Central Illinois
Issued by NWS Central Illinois
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869 FXUS63 KILX 052003 AFDILX Area Forecast Discussion National Weather Service Lincoln IL 203 PM CST Fri Dec 5 2025 .KEY MESSAGES... - Expected snowfall amounts this weekend have trended downward some, especially toward the I-72 corridor. The highest chances of more than 2 inches are north of Peoria and Galesburg (about a 60% chance). - Some potential exists for light freezing drizzle as the snow ends early Sunday. - Temperatures warm enough for rain to occur with the next system toward mid week. && .SHORT TERM... (Through Sunday) Issued at 200 PM CST Fri Dec 5 2025 Main concern during this time frame will be with the upcoming clipper system. Morning models have trended northward in the track of the snow accumulations, with the CAM guidance bringing the surface low to near the IA/IL/MO triple point by early Sunday. As such, heavier snow amounts are focusing from central Iowa into northern Illinois. Tail end of the HREF highlights about a 40-50% chance of more than 2 inches from about Monmouth-Pontiac north, with the NBM about 10% higher. The I-72 corridor is down to about a 30-40% chance of an inch. With the northern track, there is a little more concern for mixed or freezing precip across the heart of the forecast area. Latest NAM soundings show a noticeable inversion around 3000 feet as the column moistens from the top down, and a loss of ice crystals as we get into early Sunday morning. This would point to some drizzle or freezing drizzle potential, as temperatures are expected to rise to freezing across the south half of the forecast area. However, there is no significant "warm nose" of above-freezing temperatures off the surface, generally only getting up to around +1C in the inversion. Will need to watch this potential as we get closer, as road temperatures are likely to remain below freezing. For now, will only mention snow or a rain/snow mix in the forecast. Much of the precip should be out of the area by late Sunday morning. No winter weather headlines are planned at this time. Temperatures remain below normal through the weekend, but they should at least be more reasonable. Can`t rule out some 40 degree readings south of I-70 where snow cover is more likely to melt off this weekend. Geelhart .LONG TERM... (Monday through Next Friday) Issued at 200 PM CST Fri Dec 5 2025 No significant changes in the forecast thinking for the upcoming work week. While we remain a general northwest upper flow, a good portion of that will be coming from more of a Pacific flow, resulting in some milder (relatively speaking) temperatures for a time. However, ridging becomes more prominent along the West Coast by late week, with another surge of colder temperatures into the Midwest. Clipper systems will zip southeast every couple of days, with the Tuesday night system the strongest. This one is also the farthest north, and is likely to be more of a rain maker this far south. While the longer range models bring the next one into the central U.S. Thursday night or early Friday, the GFS appears to be too far north at this time. European ensembles are further south, but are fairly evenly split in the timing and/or snow potential. NBM precipitation chances near 20% will be sufficient at this point. Geelhart && .AVIATION... (For the 18z TAFs through 18z Saturday Afternoon) Issued at 1108 AM CST Fri Dec 5 2025 A mid-level cloud deck (around 8 kft) will shift east across the terminals through early afternoon, then give way to scattered cirrus. VFR conditions are expected to prevail until around 09-10z tonight, when MVFR ceilings push in from northwest to southeast. Some IFR ceilings are also possible, with the greatest potential being at KBMI/KCMI. Once ceilings drop down, minimal improvement is anticipated through 18z Saturday. Winds will be southerly today, but turn clockwise in time, becoming northwesterly by Saturday morning. Erwin && .ILX WATCHES/WARNINGS/ADVISORIES... None. && $$