551
FXUS63 KILX 052300
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
500 PM CST Fri Dec 5 2025

.KEY MESSAGES...

- Expected snowfall amounts this weekend have trended downward
  some, especially toward the I-72 corridor. The highest chances
  of more than 2 inches are north of Peoria and Galesburg (about a
  60% chance).

- Some potential exists for light freezing drizzle as the snow
  ends early Sunday.

- Temperatures warm enough for rain to occur with the next system
  toward mid week.

&&

.SHORT TERM... (Through Sunday)
Issued at 200 PM CST Fri Dec 5 2025

Main concern during this time frame will be with the upcoming
clipper system. Morning models have trended northward in the track
of the snow accumulations, with the CAM guidance bringing the
surface low to near the IA/IL/MO triple point by early Sunday. As
such, heavier snow amounts are focusing from central Iowa into
northern Illinois. Tail end of the HREF highlights about a 40-50%
chance of more than 2 inches from about Monmouth-Pontiac north,
with the NBM about 10% higher. The I-72 corridor is down to about
a 30-40% chance of an inch. With the northern track, there is a
little more concern for mixed or freezing precip across the heart
of the forecast area. Latest NAM soundings show a noticeable
inversion around 3000 feet as the column moistens from the top
down, and a loss of ice crystals as we get into early Sunday
morning. This would point to some drizzle or freezing drizzle
potential, as temperatures are expected to rise to freezing across
the south half of the forecast area. However, there is no
significant "warm nose" of above-freezing temperatures off the
surface, generally only getting up to around +1C in the inversion.
Will need to watch this potential as we get closer, as road
temperatures are likely to remain below freezing. For now, will
only mention snow or a rain/snow mix in the forecast. Much of the
precip should be out of the area by late Sunday morning. No winter
weather headlines are planned at this time.

Temperatures remain below normal through the weekend, but they
should at least be more reasonable. Can`t rule out some 40 degree
readings south of I-70 where snow cover is more likely to melt
off this weekend.

Geelhart

.LONG TERM...  (Monday through Next Friday)
Issued at 200 PM CST Fri Dec 5 2025

No significant changes in the forecast thinking for the upcoming
work week. While we remain a general northwest upper flow, a good
portion of that will be coming from more of a Pacific flow,
resulting in some milder (relatively speaking) temperatures for a
time. However, ridging becomes more prominent along the West Coast
by late week, with another surge of colder temperatures into the
Midwest.

Clipper systems will zip southeast every couple of days, with the
Tuesday night system the strongest. This one is also the farthest
north, and is likely to be more of a rain maker this far south.
While the longer range models bring the next one into the central
U.S. Thursday night or early Friday, the GFS appears to be too far
north at this time. European ensembles are further south, but are
fairly evenly split in the timing and/or snow potential. NBM
precipitation chances near 20% will be sufficient at this point.

Geelhart

&&

.AVIATION...  (For the 00z TAFs through 00z Saturday Evening)
Issued at 500 PM CST Fri Dec 5 2025

A cold front was pushing into central IA at 23z, and will cross
the central IL terminals from the northwest tonight. Ahead of the
front south to southwest winds around 10 kt and VFR skies will
prevail. MVFR ceilings will overspread the region behind the
front, with highest probabilities of IFR conditions occurring at
KBMI-KDEC-KCMI. These clouds look to linger over the area through
much of Saturday.

25

&&

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

$$