638
FXUS63 KILX 131932
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
132 PM CST Thu Nov 13 2025

.KEY MESSAGES...

- Temperatures will top out in the upper 60s to mid 70s Friday and
  Saturday as breezy southwest winds set up over the region.

- The next notable chance for rain (60%) will be late Monday into
  Tuesday, though precip amounts are generally expected to remain
  under a half inch, and will do little to improve the ongoing
  drought conditions.

&&

.DISCUSSION...
Issued at 118 PM CST Thu Nov 13 2025

This afternoon, an expansive surface high centered over the Deep
South with ridging extending across the Midwest into the Upper
Midwest is resulting in fair weather across the region. Aloft, a
strong upper ridge spans the Great Plains. As these features drift
east Friday and Saturday, return flow behind the surface ridge
axis will overspread central Illinois with breezy south to
southwest winds developing. This will help push temps back into
the 70s for western/southern portions of the forecast area Friday
and most of central/SE Illinois Saturday. NBM probabilities for
reaching/exceeding 70 degrees runs 80% or higher from roughly the
I-74 corridor south and west of I-57 with probabilities tapering
off over east central Illinois. The 80% probability covers
everywhere south of Havana to Danville Saturday.

Meanwhile, there are two features to keep an eye on late this
weekend into next week. A pair of closed upper lows are currently
located off the CA/OR coast and over British Columbia. The
northern low is expected to track east to Hudson Bay Saturday
helping to break down the upper ridge, while a surface low
develops in response. The low tracks well to our north, but it
does push a cold front across central Illinois late Saturday.
Guidance generally favors a dry frontal passage over central
Illinois due to our displacement from the main upper level
disturbance and poor diurnal timing. However, the NAM and its
forecast sounding do suggest a few light sprinkles will be
possible. Regardless of the precip chances, northwest flow will
overspread central Illinois behind the front with strong cold air
advection quickly driving down temps. Highs in the 70s Saturday
will give way to overnight lows in the 30s followed by highs only
in the 50s Sunday afternoon.

The southern upper low is progged to dig across SoCal late
Saturday and then lift across the Intermountain West Sunday
night. While uncertainty in the track of the upper low grows
quickly from this point, the general theme between the models
suggest that a surface low will develop over the central Great
Plains with a warm front setting up across the mid Mississippi
Valley. There will be a chance for showers locally along the front
with some uncertainty in the precip type as a deep isothermal
layer hovering near 0C will be in place from the surface to around
700mb. Northern portions of the forecast area could see a little
snow, though NBM conditional p-type probabilities still favor
rain 4 to 1 or better over snow. In addition, steep mid/upper
lapse rates may allow for a few isolated elevated thunderstorms.

Deubelbeiss

&&

.AVIATION...  (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1121 AM CST Thu Nov 13 2025

VFR conditions with mainly light/variable winds are expected
through most of the 18z TAF period. Winds become more out of the
southwest by 15z but remain light (5-7 knot).

Copple

&&

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

$$