098
FXUS63 KILX 172331
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
531 PM CST Wed Dec 17 2025

.KEY MESSAGES...

- Inclement conditions are expected tomorrow, with breezy winds
  and a high chance of rain (over 90%). Despite a mild start,
  temperatures will fall sharply during the day as a strong cold
  front sweeps across the region.

- Snow showers with the potential to limit visibility and create
  slippery evening commute conditions are forecast from 4pm to 9pm
  tomorrow evening.

- The wind gusts tomorrow may approach 45 mph at times. Winds will
  be out of the south during the morning, then out of the west-northwest
  during the afternoon and evening.

- Temperatures fluctuate through the weekend. The coldest
  conditions are expected Friday morning, when wind chill values
  will drop to near to below zero north of I-72. Above normal
  temperatures remain likely next week (70-80% chance).

&&

.DISCUSSION...
Issued at 149 PM CST Wed Dec 17 2025

Today winds will shift to a more southerly flow, increasing the WAA
and moisture return. No precipitation is expected for the remainder
of the day. A low pressure system is deepening over the northern
Plains today, strengthening the pressure gradient over the mid-
CONUS. Winds will begin picking up overnight, ahead of the cold
frontal passage tomorrow morning. The stronger, southerly winds will
increase the WAA overnight. Because of the timing of this system,
temperatures will act in a non-diurnal way. The high for tomorrow
(46-55 degrees) will occur in the morning ahead of the cold front,
then will decrease throughout the day. Winds will continue to be
strong behind the front, but from the NW instead. CAA will be
decent, bringing in below to near freezing temperatures back to the
forecast area for Friday.

Focusing a little closer on the winds for tonight into tomorrow, we
can take a look at the probabilistic ensembles. A strong low-level
jet will set up over Illinois with 60 mph winds a few thousand feet
AGL. The HREF is likely over mixing, therefore showing too high of
wind gusts. The NBM is showing 40-50% chance of wind gusts exceeding
35 mph through tomorrow morning. As the front passes through,
showers and potentially some rumbles of thunder are expected. Some
of these showers/t`storms could get near severe if they can
successfully mix down the very strong winds from the LLJ. Later in
the day tomorrow, winds will pick back up again. After 00z, wind
gusts over 30 mph are possible north of I-72, with a 40-70% chance
of greater than 35 mph wind gusts. Winds will relax as we move into
Friday morning.

Behind the front tomorrow afternoon into the evening, we could see
some snow showers as the CAA drops the temperatures. Overall,
amounts from the showers should remain minimal, around maybe a tenth
or two. However, there is a signal for the potential of snow squall
development. There is a decent area of FGEN around 00z-03z based off
the models, with 30-40 J/kg of instability (SBCAPE) and >1 snow
squall parameter co-located. Timing for development is from 22z
Thursday to 03z Friday (4pm-9pm Thursday). Snow amounts aren`t
expected to be high, maybe a couple tenths for the most part with
the showers. With any snow squall that develops rapidly
deteriorating road conditions and limited visibility. When heading
home for the evening tomorrow, stay aware of the weather and its
impacts.

Dry weather will settle in for the weekend by Friday morning. Highs
will bounce around this weekend before leveling out by mid-week.
Friday highs will be in the low to mid 30s, with lows in the teens
that morning. Saturday will warm up into the upper 40s to low 50s,
with lows in the 20s. Sunday will drop back into the upper 30s to
low 40s, with lows in the 20s. By Tuesday and Wednesday,
temperatures will get back int to upper 40s to upper 50s.

Copple

&&

.AVIATION...  (For the 00z TAFs through 00z Thursday Evening)
Issued at 529 PM CST Wed Dec 17 2025

VFR conditions are expected to persist throughout this evening.
Winds from the southwest will become gusty late tonight due to a
tightening pressure gradient preceding an approaching front.
Conditions will rapidly deteriorate after 06Z, with ceilings
dropping to MVFR/IFR and the development of a strong low-level
jet.

Overnight, surface wind gusts will peak around 25 kt, while winds
at 2,000 feet are anticipated to approach 50-55 kt.

Shower activity will increase after 09Z, with the best chances
for precipitation occurring with the frontal passage after 13Z
Thursday morning. Gusty winds will be a feature of the showers and
frontal passage, with surface gusts potentially reaching 45 kt in
the strongest activity. A low probability (less than 20% chance)
of a few rumbles of thunder exists with the frontal passage.
Following the front, winds will shift to the west and remain gusty
through the afternoon.

MJA

&&

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

$$