587
FXUS63 KLOT 252312
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
612 PM CDT Fri Sep 25 2026

.KEY MESSAGES...

- Near to slightly below normal temperatures are forecasted over
  the next several days.

- The next chance for a widespread soaking rainfall won`t come
  until at least the middle of next week.

&&

.DISCUSSION...
Issued at 1244 PM CDT Fri Sep 25 2026

Over the next few days, a deepening coastal low along the
northeastern seaboard on the eastern flank of an upper-level
ridge over Upper Midwest will reinforce a Rex-like blocking
pattern across the Great Lakes. As a result, relatively
quiescent conditions will continue across our area through into
early next week with no weather concerns of note. Highs will
range from the upper 60s to lower 70s, lows will fall to the
upper 40s to lower 50s, and winds will remain fairly light (10
mph or less) out of the east. Upper-level shortwaves will meet
their demise as they propagate toward the blocked upper- level
pattern, leading to occasional periods of mid to upper- level
cloud cover and perhaps a few sprinkles particularly through
Sunday morning.

Toward the middle of next week, a series of waves originating
from the northern Pacific region will lead to the development of
a more progressive pattern across the CONUS. Ensemble
probabilities for soaking rain increase incrementally across
much of the central and Midwestern US by the middle of the week
as each wave propagates overhead. With that said, will note
less clarity on exact details (favored time windows, rainfall
amounts, opportunity for thunder) owing to spread on the
evolution, speed, and arrival time of each wave. Whether or not
the remnants of Pacific hurricane Polo influences the large-
scale pattern remains an item of interest, as well. Blended NBM
guidance offers broad-brushed change to likely (30-60%) PoPs
from Wednesday into the first few days of October, which seems
fine for the time being.

Borchardt

&&

.AVIATION /00Z TAFS THROUGH 06Z SUNDAY/...
Issued at 612 PM CDT Fri Sep 25 2026

There are no significant aviation weather concerns. BKN-OVC
clouds around 10 kft will scatter this evening, with SCT-BKN
cirrus continuing across the region at times. There is a small
potential for some patchy shallow BR, but the signal is too low
and isolated to warrant any mention in the TAFs at this time.
Light east/northeasterly winds under 10 kts may trend
light/variable or light northwesterly late tonight before
becoming e/ese again on Saturday.

Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

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