117
FXUS63 KILX 241045
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
545 AM CDT Sun Aug 24 2025

.KEY MESSAGES...

- Dry and seasonably cool conditions are expected this week, with
  daily highs generally in the 70s and lows in the upper 40s to
  mid 50s. The probability of any weather impacts is low (less
  than 10%).

&&

.DISCUSSION...
Issued at 106 AM CDT Sun Aug 24 2025

At 1 am, mid level water vapor satellite showed the shortwave
responsible for our isolated evening showers and storms edging into
the Ohio Valley Region, with an unseasonably dry airmass over
central IL in its wake; in fact, SPC mesoanalysis suggests PWATs
have fallen to less than 0.7", or roughly our 10th percentile from
sounding climatology. At the surface, temperatures are in the upper
50s to mid 60s, and still falling amidst clear skies and easing
northwest winds. Expect temperatures to bottom out in the mid 50s by
sunrise, rising only into the mid 70s this afternoon as cool
advection restrengthens with the diurnal increase in northwest
winds, which will gust around 20 mph at times.

A few of the CAMs are depicting some light reflectivities across our
north today and tomorrow, but we suspect the chance of anything
reaching the surface is quite low (less than 10%) given the dry
layer below any instability showing up on forecast soundings. If we
do get reports of sprinkles out of more robust diurnal cu this
afternoon then we`ll likely need to add that into the forecast for
both today and tomorrow, possibly Tuesday as well (with another
shortwave arriving).

The dry and seasonably cool airmass is slated to remain in place
right through the end of the work week, when temperatures start to
trend upward once again. Forecast highs, which are solidly in the
70s through Wednesday, climb to around 80 by Thursday and Friday.
With surface high pressure in place through the week, light winds
and few clouds should make for efficient nocturnal radiational
cooling, especially Monday and Tuesday nights when NBM advertises 40-
50% chances for lows in the 40s.

Bumgardner

&&

.AVIATION...  (For the 12z TAFs through 12z Monday Morning)
Issued at 545 AM CDT Sun Aug 24 2025

Mostly clear skies will give way to VFR diurnal cu after around
16z/11am. Northwest winds will increase mid morning with gusts
around 20 kt this afternoon, then abate after around 00z/7pm.
Light winds and mostly clear skies may result in patchy fog early
Monday morning, but the probability (10-15%) is too low to add
anything to the forecast at this time.

Bumgardner

&&

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

$$