724
FXUS63 KLOT 290640
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
140 AM CDT Wed Jul 29 2026

.KEY MESSAGES...

- Rain expected to develop during the day Friday, continue into
  Friday night, before ending Saturday. Widespread rainfall
  totals over an inch are possible.

&&

.DISCUSSION...
Issued at 140 AM CDT Wed Jul 29 2026

Quiet weather expected through Thursday night with seasonably
warm temperatures and very comfortable humidity levels. Lake
breezes both today and tomorrow will result in some modest
cooling right along the lakefront. While skies should be sunny
today, wildfire smoke aloft will likely filter the sun some.

Guidance continues to bring a strong northern stream shortwave
trough into the Midwest Friday. Our area will remain on the cool
side of the developing surface low, so the better instability
and thunderstorm chances should remain south of our CWA.
However, strong synoptic ascent and seasonably high PWATs could
allow for a pretty good soaking for areas that end up under the
deformation zone rain Friday night, which looks to be most of
our CWA. The cloud cover and developing rain on Friday should
result in below average temps; mostly in the 70s, except lower
80s eastern most CWA where rain will arrive last.

Lower confidence in the forecast details Saturday as there is
spread in guidance in how quickly this system moves out. Medium
range guidance has trended away from cutting off a mid-upper
level low that meanders around the region and now is more
progressive pushing the trough southeast of the area. Timing of
the trough`s departure will impact rain chances and temperatures
over the weekend. Given the lower than average forecast
confidence, no changes were made to NBM which maintains cooler
temps and rain into Saturday. If guidance continues to trend
quicker, then later Saturday and especially Sunday could end up
dry. Next week looks to start dry and seasonably warm.

- Izzi

&&

.AVIATION /06Z TAFS THROUGH 12Z THURSDAY/...
Issued at 1208 AM CDT Wed Jul 29 2026

Quiet, VFR flying conditions can be expected through the period,
with north to northeast winds (near/around 10 kt this afternoon
near the lake).

Castro

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Beach Hazards Statement until 10 AM CDT this morning for
     ILZ006-ILZ103-ILZ104.

IN...Beach Hazards Statement until 10 AM CDT this morning for
     INZ001-INZ002.

LM...Small Craft Advisory until 7 AM CDT this morning for the IL
     and IN nearshore waters.

&&

$$

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