339 FXUS63 KLOT 101117 AFDLOTArea Forecast Discussion National Weather Service Chicago/Romeoville, IL 617 AM CDT Fri Oct 10 2025
.KEY MESSAGES...
- Chance of showers (30%) through this evening with a slight chance (20%) for thunder across northwest IL this morning.
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.DISCUSSION... Issued at 227 AM CDT Fri Oct 10 2025
A weakening cold front will approach the area today and move across the area tonight. A line of showers with a few embedded thunderstorms that currently extends from southwest WI into south central IA will move across northwest IL through mid morning and is expected to slowly dissipate as it spreads across eastern IL by early afternoon. Best thunder chances, which will still be quite low, will be across northwest IL this morning and included slight chance thunder mention for a few hours. Its possible much of this activity will dissipate by early afternoon, with perhaps just sprinkles/virga and pops show this trend downward through the afternoon. There is some potential for showers to redevelop this evening, mainly south of I-80 and east of I-57. Current forecast has slight chance pops and maintained those with this forecast.
Southwest winds will increase after sunrise with gusts possibly into the 25-30 mph range for a time through early afternoon and then speeds/gusts may diminish through the afternoon. Winds will begin to shift westerly this evening and then shift northerly with the cold front later this evening and overnight.
High temperatures today are tricky. The increasing clouds may keep temps a bit cooler, perhaps mid 60s across northern IL but if the clouds are not as thick and/or precip dissipates faster, this may allow for warmer temperatures, which could warm into the lower 70s across the southeast third of the cwa. Lows tonight are also challenging. Despite the cold front, much of guidance has warmed low temps several degrees for Saturday morning. Have warmed temps a few degrees from the previous forecast, but trends will need to be monitored.
Models continue to hint at lake effect rain showers Saturday but the potential appears to be east of the area Saturday morning with the best chance, and still very low, midday into Saturday afternoon. Opted to keep the forecast dry for now.
Another weakening cold front will approach the area Monday and appears similar to today`s cold front. Increasing cloud cover with the best chance of showers across northwest IL with a dissipating trend across the rest of the area. Blended pops are mainly dry for this time period and maintained a dry forecast.
High pressure then appears to settle across the Great Lakes region through the middle of next week which should keep the area in easterly flow and generally dry. cms
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.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/... Issued at 617 AM CDT Fri Oct 10 2025
Key messages:
- Breezy southwest winds today (Gusts up around 20 kt).
- A few isolated to widely scattered showers through early to mid afternoon.
- Northerly wind shift with a cold front this evening (likely after 02Z).
While no significant weather concerns are anticipated through the period, there will be a period of breezy southwest winds through the daylight hours today. Increasingly low-level moisture on these southwest winds will also continue to help foster at least some isolated to widely scattered showers today as a weather disturbance shifts into the western Great Lakes. In fact, we are already seeing some of these showers move in across northwestern IL early this morning. A very low (
NWS LOT Office Area Forecast Discussion