textproduct: Central Illinois

KEY MESSAGES

- Gusty south winds (30-40mph) will occur Thursday night, switching to westerly on Friday. There is a 60-80% chance gusts exceed 40 mph at times on Friday north of I-72/Danville, resulting in difficult driving conditions for high profile vehicles.

- A strong cold front will bring scattered thunderstorms, strong winds, and then sharply colder conditions Sunday into Monday. There is a 30-50% chance wind chills fall below 0 Monday morning and again Monday night north of I-72/Danville.

DISCUSSION

Issued at 201 PM CDT Wed Mar 11 2026

***** TONIGHT AND TOMORROW *****

Early Wednesday afternoon, thunderstorms were located along a cold front extending from southern Illinois into southwest Ohio, while an area of stratiform rain was positioned near I-55. We've had reports of snow mixing in with this activity, but the ground has been too warm for any of it to stick.

We should hold on to just enough of a northwest wind to prevent substantial radiational losses tonight, though with HREF advertising high confidence (90% chance) we'll lose cloud cover tonight temperatures should have no trouble dropping into the upper 20s or at least low 30s.

***** WINDY, SHARP TEMPERATURE SWINGS THROUGH THE WEEKEND *****

A shortwave trough and compact attendant surface low are forecast to move into the area tomorrow night. Strong pressure gradients will accompany the low, bringing a round of gusty winds first out of the south-southwest tomorrow night and then out of the west-northwest behind the cold front on Friday. Uncertainty exists in the magnitude of these winds, especially the south winds overnight; CAMs often overmix the LLJ winds down to the surface in these cases, but not always. Bufkit soundings from various models suggest we'll most- likely remain elevated, but if not gusts over 50 mph may occur. In the cold advection regime on Friday, mixing will be deeper but winds aloft will be weakening as the system departs to our east. NBM still gives a 60-80% chance winds gust over 40 mph (highest north of I-74) on Friday.

Warm advection will return Saturday night into Sunday, and depending on the arrival time of the cold front the area could get quite warm Sunday afternoon. At this time, NBM gives an 80-90% chance for high temperatures of 60+ degrees south of roughly I-70, tapering to 30- 40% west of the IL River. Another round of strong winds will accompany this system, with medium confidence (50-70% chance) we'll need a Wind Advisory for at least a portion of the CWA late Sunday into Monday. We may also wind up with some thunderstorms along that cold front, as dewpoints climb into the 50s and surface CAPE potentially rises into the 300-700 J/kg range. Confidence in whether a severe weather risk can materialize at this point is low.

***** MUCH COOLER NEXT WORK WEEK *****

Besides the wind, temperatures will turn sharply colder by Monday with lows potentially falling into the teens during the morning and then teens to locally single digits Tuesday morning. Both Sunday and Monday night, wind chills may (30-50% chance) fall below 0 north of I-72/Danville.

Bumgardner

AVIATION

(For the 06z TAFs through 06z Thursday Night) Issued at 1219 AM CDT Thu Mar 12 2026

Ridge of high pressure will move across central Illinois Thursday morning while low pressure approaches the region from the Upper Midwest late in the period. A modest NW breeze overnight will back to the southwest then to the south Thursday behind the ridge axis. Winds will begin to ramp up Thursday evening ahead of the approaching low. Winds aloft will increase to 55-60 kt near the end of the period resulting in low level wind shear. Expect increasing mid clouds through 06Z.

Deubelbeiss

ILX WATCHES/WARNINGS/ADVISORIES

None.