541
FXUS63 KILX 312250
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
550 PM CDT Thu Jul 31 2025

.KEY MESSAGES...

- Decreased air quality is expected across parts of central
  Illinois this afternoon and evening as Canadian wildfire smoke
  drifts southward into the area.

- Below normal temperatures will prevail through the upcoming
  weekend...with highs mostly in the 70s to around 80 degrees.

- The next significant chance for rain will hold off until early
  next week.

&&

.DISCUSSION...
Issued at 137 PM CDT Thu Jul 31 2025

...Smoke from Canadian Wildfires over portions of central IL...

Surface observations from northern LP Michigan into southeast IA
and areas to the north show visibility of 3 to 5 miles in smoke
early this afternoon, coincident with AirNow.gov air quality
monitoring in the Unhealthy/Unhealthy for Sensitive Groups
categories (101-200 PM2.5 concentration). With northeast low level
winds circulating around high pressure centered over Lake
Superior, this smoke should continue to drift southwestward. The
high concentrations have prompted the Illinois EPA to request an
Air Quality Alert from around the Peoria Metro area northward in
Illinois, until midnight. Current guidance suggests smoke
concentrations should diminish late in the night, but the
situation will be monitored.

...Dry and cooler through the weekend...

The high pressure centered near Lake Superior will be the
dominant feature for central IL the next few days, keeping
precipitation absent at least through the weekend, mostly clear to
partly cloudy skies, and generally light northeasterly winds,
decreasing in speed from today`s breezy northeast winds as the
high slowly sinks southward. A cooler and drier air mass that has
already settled over the area will linger for the weekend as upper
level flow from the northwest continues to transport cooler air
over the region. Highs only in the upper 70s to around 80, and
lows dipping into the upper 50s are expected through the weekend.

...Precipitation chances returning early next week...

The next rain chances develop early next week as the high over the
region weakens and moves off to the northeast, while a low pressure
trough develops into the Plains to mid Mississippi Valley region.
There should be enough southerly flow ahead of this feature to
increase moisture over the region and establish a warming trend for
next week. Given uncertainty in the progression of this trough, low
chances for precipitation span Monday afternoon through Tuesday
evening, but those will likely become somewhat more confined as the
system approaches. Late in the week, we could see a few additional
chances for precipitation as disturbances track through the northern
Plains into the MidWest on the northern periphery of a ridge over
the southwest and southern Plains.37

&&

.AVIATION...  (For the 00z TAFs through 00z Friday Evening)
Issued at 550 PM CDT Thu Jul 31 2025

Skies to clear quickly this evening. Wildfire smoke will reduce
visibility to MVFR at times overnight. Based on latest HRRR smoke
product, will improve visibilities around 09-11z. Northeast winds
will decrease over the next hour, then increase to around 10 kt
by mid morning Fri.

25

&&

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

$$