550
FXUS63 KILX 021052
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
552 AM CDT Sat Aug 2 2025

.KEY MESSAGES...

- Smoke from wildfires will persist over central Illinois today,
  though the greatest concentrations will remain aloft. At the
  surface moderate air pollution is expected, though is an
  improvement from yesterday.

- Comfortable humidity levels will be in place through the weekend
  along with below normal temperatures. Any precip should hold off
  until next week.

&&

.DISCUSSION...
Issued at 158 AM CDT Sat Aug 2 2025

High pressure will persist over the Great Lakes region through
the weekend, leading to significantly lower humidity levels and
below-normal temperatures across central Illinois. Northeast
winds, gusting to around 15 mph, are anticipated from late morning
through this evening and will continue to advect 50-degree dew
points into the region, reinforced by deep mixing. This low-level
northeast flow will help maintain temperatures below the normal
high of 85-86 degrees. Highs are expected to be in the upper 70s
to around 80 today and will warm by another degree or two on
Sunday.

In addition, wildfire activity upstream will continue to advect
smoky and hazy conditions into the region, though impacts will be
mainly aloft today. Regional observations indicate that the
earlier reported reduced surface visibility across the region has
generally improved with most sites now above 6SM visibility
overnight. Near-surface smoke is projected by the HRRR/RAP to be
in much lower concentrations across central Illinois today. EPA
projections still show moderate air quality pollution, but this
remains an improvement from the unhealthy quality yesterday.
Aloft, westerly flow will advect in additional high-level smoke
through the remainder of the weekend.

The surface ridge axis will gradually shift eastward through the
upcoming week, causing surface winds across central Illinois to
veer southeasterly. While not the most efficient return flow, dew
points are expected to gradually increase, reaching the 60s early
in the week and eventually the 70s by midweek. A blocky upper
ridge will be present over the southwest CONUS for much of next
week, positioning central Illinois near an area of split flow
downstream. Consequently, significant forcing areas are absent,
with the main storm track and jet stream retreating well
northward. Precipitation chances will be largely confined to
isolated to widely scattered afternoon/evening convective activity
due to the lack of notable synoptic forcing.

Deubelbeiss

&&

.AVIATION...  (For the 12z TAFs through 12z Sunday Morning)
Issued at 552 AM CDT Sat Aug 2 2025

High pressure will remain over the Great Lakes resulting in a
modest NE breeze across central Illinois through the period. Winds
will increase into the 9-12kt range late this morning through
around sunset this evening. Haze and smoke from wildfires linger
over the region but vsby has improved back to VFR and should
remain VFR the remainder of the period.

Deubelbeiss

&&

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

$$