662
FXUS63 KLOT 021103
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
603 AM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Wildfire smoke will create hazy skies.

- Temperatures will gradually warm early next week to seasonal
  normal values

&&

.DISCUSSION...
Issued at 242 AM CDT Sat Aug 2 2025

Surface high pressure is expected to remain over the Great
Lakes today and Sunday with no precipitation in the forecast.
High temperatures expected this afternoon in the mid-to-upper
70s. It should be an otherwise nice day, but lingering wildfire
smoke will likely keep the skies somewhat hazy. While there is
lower confidence in the exact timing of the smoke clearing out,
cloud cover should diminish overnight into Sunday morning with
low temperatures in the lower 60s for the city and 50s away from
Chicago. The clearer skies will allow temperatures to warm up
on Sunday afternoon into the lower 80s, with upper 70s along the
shoreline as onshore winds help keep it slightly cooler.

Early next week, the previously mentioned surface high will
very slowly weaken and start to drift east as an upper level
ridge sits over the western CONUS and a weaker ridge builds
over central Canada. Models are suggesting that another mid
level trough is expected to descend down the CONUS ridge early
next week as moisture from the Gulf and the Atlantic gets drawn
up around the surface high to the east and into Illinois. There
is still uncertainty on the timing of the trough`s movement,
but this would ultimately support isolated to widely scattered
diurnally-driven thunderstorms as close as central Illinois
Monday afternoon and over the entire forecast area on Tuesday
and possibly into Wednesday. However, a majority of the forecast
area should remain dry during this period, though highest
chances currently remain on Tuesday afternoon. Another broader
trough moving over the Great Lakes late next week has the
potential to bring another chance for showers and storms next
weekend.

DK

&&

.AVIATION /12Z TAFS THROUGH 18Z SUNDAY/...
Issued at 602 AM CDT Sat Aug 2 2025

High pressure will keep VFR conditions around the terminals
through the current period. Winds will remain onshore at or
below 10 knots this afternoon. Wildfire smoke remains in the
region for hazier skies and may result in occasional visibility
reductions to MVFR levels.

DK

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...Air Quality Alert until midnight CDT tonight for ILZ005-ILZ006-
     ILZ012-ILZ013-ILZ020-ILZ021-ILZ103-ILZ104-ILZ105-ILZ106-
     ILZ107-ILZ108.

IN...Air Quality Alert until midnight CDT tonight for INZ001-INZ002-
     INZ010-INZ011.

LM...None.

&&

$$

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