791
FXUS63 KLOT 201756
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
1256 PM CDT Tue Oct 20 2026

.KEY MESSAGES...

- Areas of fog, some potentially dense, may develop again early
  Wednesday morning near Lake Michigan.

- An extended period of dry and above to much above average
  temperatures is expected through the upcoming weekend.

&&

.DISCUSSION...
Issued at 154 AM CDT Tue Oct 20 2026

No significant weather is expected through the upcoming weekend
with above to much above average temperatures each day.
Generally light winds should allow weak lake breezes to form
each of the next several afternoons, but only result in slightly
cooler conditions right near the lake. A modest increase in
moisture in the wake of the afternoon lake breezes could allow
for some ground fog to form during the early morning hours the
next few days. Otherwise, look for mostly sunny conditions for
the remainder of the work week.

- Borchardt/Izzi

&&

.AVIATION /18Z TAFS THROUGH 00Z THURSDAY/...
Issued at 1255 PM CDT Tue Oct 20 2026

Key aviation forecast messages:

- IFR or lower VSBYs in BR/FG may develop again early WED AM.

The primary concern through the period is the potential for
fog near Lake Michigan early Wednesday morning, some of which
may become locally dense. Model guidance that performed well
with this morning`s dense fog depicts another round of fog
development over a similar area and extends slightly farther
southeast. Have accordingly included MDW with the reduced VSBYs
as low as 1 SM with this update to hint at increasing confidence
in fog development. If this signal persists and additional
guidance begins to pick up on the potential for dense fog, LIFR
(or lower) conditions may need to be introduced with later
updates.

Otherwise winds will remain light (under 10 kt) initially out of
the SE, turning E to ENE behind a weak lake breeze this
afternoon. Winds then ease and become light and variable again
overnight eventually settling into a SSW direction after
daybreak Wednesday.

Petr

&&

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

&&

$$

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