194
FXUS63 KILX 021919
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
219 PM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Smoke from wildfires will persist over central Illinois the next
  few days, though much of the time the greatest concentrations
  will remain aloft.

- Comfortable humidity levels will continue through the weekend,
  along with below normal temperatures. Any precipitation should
  hold off until Monday or Tuesday as increased humidity returns.
  A warming trend will continue through the week.

&&

.DISCUSSION...
Issued at 219 PM CDT Sat Aug 2 2025

High pressure will continue over the Great Lakes region through the
weekend, keeping a mild and dry air mass over central IL with a
northeast flow predominant. Meanwhile, wildfire smoke from Canada
will continue to circulate around the high, keeping skies hazy and
occasionally mixing higher concentrations down to the surface.
Presently, upstream observations don`t indicate any increasing
concentrations of near-surface smoke, however this will be watched
for. AirNow.gov forecasts are for Unhealthy for Sensitive Groups
(USG) concentrations north of the Illinois River both today and
tomorrow, with Moderate to the south. This is another step down
from what was seen around central IL yesterday. Temperatures look
to dip into the upper 50s again tonight, with highs reaching
around 80 Sunday.

The pattern will shift enough for a substantial change in weather
early in the work week as the high weakens and moves off to the
east, while a weak upper level trough develops just west of the
Mississippi River Valley. This will allow moisture to return to
southeast and eventually central IL as the flow direction turns
southeasterly. While any lift or vertical wind shear looks to be
quite weak, the environment should become supportive of scattered
thunderstorms developing for afternoon and evening periods, starting
first in southeast IL Monday and spreading throughout most of the
area by Tuesday. Wednesday, thunderstorm activity looks to become
confined to southeast IL again as ridging builds into western
areas to bring a more subsident environment. This ridge looks to
keep storm activity confined to areas to the north or southeast
for late in the week, possibly breaking down over the weekend with
more uncertainty in storm potential regionally. Temperatures will
follow a warming trend, starting with highs in the lower 80s
early in the week to upper 80s late in the week.

37

&&

.AVIATION...  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1214 PM CDT Sat Aug 2 2025

The circulation around high pressure centered over WI today
continues bring light northeasterly breezes to the central IL
terminals, as well as re-circulate smoke over the region. Surface
observations continue to suggest VFR visibilities continuing for
the upcoming 24 hours, however periods of MVFR cannot be ruled out
and will need to be watched for.

37

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$