textproduct: Central Illinois

KEY MESSAGES

- Patchy fog, low stratus, and drizzle across central Il this morning. A cold front moves through tonight, resulting in sharply colder conditions for Wednesday through Friday. Highs for Thanksgiving will only be in the 30s.

- Strong northwesterly wind gusts are expected on Wednesday, with a 40-60% chance for gusts over 45 mph. A Wind Advisory has been issued for 09z Wednesday to 00z Thursday for north of a Schuyler County to Vermilion County line. The greatest impact of the winds will be felt on north-south oriented roadways like I-55, I-57, and I-39.

- A weekend system is expected to bring a mix of precip, including rain and snow. The exact timing, precipitation types, and accumulation amounts remain subject to change, but there is a 30-50% chance of 2" of snow. Those with travel plans this weekend should continue to monitor for updates.

DISCUSSION

Issued at 246 AM CST Tue Nov 25 2025

The upper low is passing off to our northwest this morning. The remaining precipitation is lingering with some light showers or drizzle. Low stratus/patchy fog/drizzle is filling in behind the precipitation. The showers/drizzle should be ending as we go into late morning, but we stay socked into the low clouds all day. The arctic cold front will pass through central and southeastern IL from 00z to 06z tonight. There could be some sprinkles or light showers along the front as it passes through.

Behind the front, strong winds on Wednesday and a bitterly cold snap for Thanksgiving enter the region. A wind advisory has been issued for 09z Wednesday to 00z Thursday for north of a Schuyler County to Vermilion County line. There is a 40-60% chance (LREF) of wind gusts over 45 mph Wednesday afternoon north of a Monmouth to Tolono line, and Wednesday is a high travel day ahead of the holiday. The greatest impact of the winds will be felt on north-south oriented roadways like I-55, I-57, and I-39. Widespread 35-45 mph wind gusts out of the west-northwest are expected on Wednesday with the strong pressure gradient passing overhead.

Highs today will be in the upper 50s. Tomorrow (behind the front), highs only get up to the upper 30s to mid 40s. Lows each morning from Thursday to Saturday are in the upper teens to mid 20s. There is a 50-80% chance of apparent temperatures being below 15 degrees north of I-70, according to the LREF, for Thanksgiving morning.

The next system that is on deck to move through the forecast area comes Friday night into Sunday morning. Exact timing of when the system moves through and precipitation transition is still too uncertain at this time. Friday night should start out as snow. Temperatures during the day Saturday look to warm to near/just above freezing, so precipitation type could transition to a rain/snow mix. With freezing surface temps and near freezing air temps, there is a small chance that there could be period of freezing rain Sunday morning, but confidence is too low at this time, so it was left out of the forecast. The NBM probability of a trace of ice is less than 10% area-wide through the weekend. The LREF is showing a 30-50% chance of 2 inches of snowfall from Sat 06z to Sun 06z north of I-70. Continue to check updated forecasts to see how the system this weekend will play out, especially if you have any travel plans for the weekend following Thanksgiving.

After this weekend, the GFS and NBM is showing a scenario of training systems through the week, next week. The Euro and Canadian is showing a high pressure building over the region behind an additional system Tuesday, without any training systems. This will be something to watch as we move closer to the first week of December.

Copple

AVIATION

(For the 12z TAFs through 12z Wednesday Morning) Issued at 524 AM CST Tue Nov 25 2025

Drizzle and fog is expected to linger, with LIFR conditions continuing for several hours. Improvement is expected to be very gradual, with IFR not expected to be reached until after 21z. Continued improvement looks on track for the evening, with potential for brief VFR around 06z. Confidence isn't great on if we will achieve VFR, so left it out for this round of TAFs.

Another cold front will arrive after 00z, bringing a chance for rain and an increase in winds. Winds becoming W 5-10 kts by around 18z, increasing to 12-16 kts with gusts up to 30-35 kts by 09z-11z.

Copple

ILX WATCHES/WARNINGS/ADVISORIES

Wind Advisory from 3 AM to 6 PM CST Wednesday for ILZ027>031- 036>038-040>046.