Savanna, IL Weather

Key Messages

- Unseasonably mild fall weather will continue through the upcoming work week, with passing clouds and lighter winds.

- Mostly dry conditions expected into the middle of the upcoming work week, with chances gradually increasing as we head towards the end of the week.

Short Term

Issued at 149 PM CDT Sat Oct 24 2026

Upper ridge will largely remain in place through Sunday, but will gradually start to flatten out overhead due to a wave digging into the north-central CONUS and a wave over the Rockies guiding weak bouts of energy into the region. As such, a cold front will remain draped off to our northwest going into tonight, slowly tracking southeast towards eastern Iowa Sunday into Monday. Under this pattern, we will continue to see llvl southwesterly flow, favoring a continuation of warm advection into the region. As a result, temperatures will remain above seasonal normals through the remainder of the weekend, with daytime temperatures in the low-mid 70s. With the boundary slowly approaching the area and weak bouts of upper level energy passing overhead, we will continue to see a mix of clouds as well. Overnight cloud cover will help moderate temperatures in the low-mid 50s tonight and Sunday night. While we will see warm advection into the region, moisture will remain quite limited. Thus, dry conditions are expected through the remainder of the weekend.

Enjoy the beautiful fall weekend!

Long Term

Issued at 149 PM CDT Sat Oct 24 2026

Monday/Tuesday...

Aforementioned wave will eject off of the Rockies and track northeast towards the northern CONUS. As this tracks northeast, the ridge overhead will continue to flatten and get shunted east of the area, with upper level southwesterly flow setting up over the region. LLVL southwesterly flow will also increase, with a surface warm front slowly passing through the area. As such, we will continue to see above normal temperatures in the low-mid 70s. As was mentioned in the previous forecast package, we will have a weak boundary nearby and subtle upper level forcing moving in. This was favoring low-end chances for precipitation, but confidence was low due to limited moisture. Latest forecast runs have come in largely dry through this timeframe, owing to too much dry air. Thus, will message a dry forecast, with passing clouds being the main sign of the slight increase in moisture.

Wednesday Onward...

Broad upper level southwest flow will set up over the central CONUS, with persistent llvl warm advection into the region. Thus, temperatures will remain above seasonal normals, with most in the mid 70s through the end of the week. Later in the week and into the weekend, we see stronger waves work into the region, ejecting off of the Rockies. These waves will increase southwesterly flow into the area, with better moisture working in. Thus, we will start to see precipitation chances increase midweek and beyond. Chances will increase for areas along and north of a line from Fairfield to Dubuque Iowa, expanding to the remainder of the area as we go into the upcoming weekend (30-60% chances Saturday into Sunday).

Aviation

Issued at 1216 PM CDT Sat Oct 24 2026

VFR conditions will prevail through the TAF period, with a southerly breeze around 10 KTs. Around 00z this evening and through tonight, winds will decrease to around 5 KTs. Otherwise, a mix of mid-high clouds will be seen through the TAF period. No sig wx is expected at this time.