218
FXUS63 KLOT 121128
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
528 AM CST Wed Nov 12 2025

.KEY MESSAGES...

- Dry conditions and warming temperatures through the end of the
  week.

- Next chance for precipitation expected early next week.

&&

.DISCUSSION...
Issued at 205 AM CST Wed Nov 12 2025

Recent mesoanalysis shows a sub-995mb low over Central Ontario
this morning, with a tight pressure gradient extending as far
south as St. Louis, Missouri. This will allow for another day of
breezy west-northwest winds over northern Illinois and
northwest Indiana. Skies should remain mostly clear allowing
temperatures to inch up into the upper 40s and low 50s.

There is also fairly deep upper level ridge analyzed over the
Rockies presently. Despite some mid-moisture riding down the
east side of the ridge for partly cloudy skies to the west
tonight, it should remain clear enough for better radiational
cooling to allow temperatures around the area to drop once again
into the low to mid 30s. However, that ridge will slowly move
eastward through the week providing drier conditions. And with
winds turning to the south-southwest allowing better warm air to
be advected in, afternoon temperatures will slowly build
through the end of the week. Highs in the 60s looks probable,
but areas southwest of the Kankakee River Valley have a real
shot of touching 70 (15 to 20 degrees above normal!) on
Saturday.

The next trough is likely to pass eastward through Canada and
over the Great Lakes on Saturday. Models are trending with a
more northerly track for this trough which would favor drier
conditions over the area. Any non-zero chance for a quick
sprinkle/shower was kept out of the forecast presently. The
only exception is that this trough will create better northwest
flow that could allow for some lake enhanced rain showers over
northwest Indiana. On Sunday surface high pressure grows once
again providing higher confidence in drier conditions then.

Beyond that, the synoptic pattern early next week looks to be a
little more active. First, an upper level low over the desert
southwest is expected to move toward northern Illinois and
Wisconsin which would be the next best chance for rain in the
area. A secondary trough out of the southwest is then projected
to move across the southern Plains toward the middle part of the
week for another round of precip. At this range, its nice to
see a more active pattern, but it likely not be an entire wash
out and have some breaks in it. One last thing to mention is
that temperatures next week will return to seasonable norms.
Afternoon highs should be well above freezing, but morning lows
could be at or below freezing. For now, modeled wet bulb
temperatures remain above the freezing mark so the forecast is
advertising only rain. Perhaps some flurries or light snow mixes
in IF these systems pass over the area during an overnight
period (especially if its closer to daybreak), but at this range
confidence is supremely low to say any frozen precip type is
even plausible.

DK

&&

.AVIATION /12Z TAFS THROUGH 18Z THURSDAY/...
Issued at 528 AM CST Wed Nov 12 2025

There are no aviation concerns through the TAF period. Light
west winds will increase by mid-morning with gusts up to 26kt or
so. A gust to 30kt may occur between 18-21Z, before winds
subside after sunset. Winds will gradually decrease even moreso
through the overnight hours, with speeds near 5kt or below by
the end of the TAF period. Occasional periods of mid- to high-
clouds will stream overhead. Finally, will have to watch for
isolated pockets of ground fog early tomorrow morning at
RFD/DPA/GYY.

Borchardt

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 9 PM CST this evening for the IL
     nearshore waters.

     Small Craft Advisory until 3 AM CST Thursday for the IN
     nearshore waters.

&&

$$

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