717
FXUS63 KILX 082016
AFDILX

Area Forecast Discussion
National Weather Service Lincoln IL
216 PM CST Sat Nov 8 2025

.KEY MESSAGES...

- Rain becomes likely tonight. Precipitation could mix with or
  changeover to snow overnight with light snow accumulations
  possible near and north of I-74.

- Sharply colder temperatures are expected Sunday through Monday
  night. Wind chill values Monday and Tuesday mornings will drop
  into the teens.

&&

.DISCUSSION...
Issued at 216 PM CST Sat Nov 8 2025

2 pm upper air analysis shows low pressure centered just south of
the Hudson Bay with a shortwave trough approaching the middle
Mississippi Valley. A surface low is in the process of deepening
over central Missouri with it forecast to slide east across south-
central Illinois this evening. Radar mosaic depicts precipitation
ongoing out ahead of the upper wave across Iowa/northern Missouri
and into parts of northern Illinois. Observations upstream are
showing mostly rain with a few snow reports sprinkled in.
Precipitation chances increase later this afternoon into tonight.
Although most will see rain through the overnight hours, a mix with
snow or all snow is expected with accumulating snow possible across
our northern counties. The last several runs of high resolution
models have keyed in on a narrow band of light accumulating snow
coinciding with an area of strong 700-900 mb frontogenetic banding.
The 850 mb 0 degree C isotherm looks to be right on the heels of the
fgen band, which would favor a rain/snow mix.

Although antecedent environmental conditions should limit overall
accumulations, there is a low chance (20-40%) for snow
accumulations to exceed 1 inch/hour near and north of I-74 for a a
couple of hours after midnight. With the nocturnal timing and
potential for higher snowfall rates, it should be enough to allow
light snow accumulations to occur mainly on elevated and grassy
surfaces. Mean snowfall amounts look to be around 1 inch or less,
though some higher end guidance favors a narrow corridor exceeding
2 inches north of a roughly Macomb to Hoopeston line. The chance
of this seems pretty low at this time, though if temperatures cool
quicker than forecast snow amounts may need to be increased.
Breezy northerly winds with gusts up to 35 mph overnight could
also result in significantly reduced visibility where
precipitation transitions to snow.

Better forcing shifts into Indiana by daybreak on Sunday, though
lake-effect snow showers/flurries could linger into the first half
of Sunday in east-central Illinois. The fetch over Lake Michigan
begins to shift to the northwest by late morning/early afternoon,
lowering chances for precipitation by afternoon. However, chances
increase once again Sunday night in east-central IL as winds turn
back to the north over Lake Michigan for a brief time.

The upper low south of the Hudson Bay will dive into the Midwest
states on Sunday with a deep trough developing over the eastern half
of the US for the start of the new week. Sharply colder
temperatures filter in Sunday through Monday night with daytime
highs only in the 30s to low 40s and overnight lows in the 20s.
Elevated winds both Monday and Tuesday nights will send wind
chills down into the teens.

Surface ridging slides across the area by midweek, turning winds to
the south and commencing a warm up. Temperatures will climb back to
the 60s to near 70 degrees by late week and persisting into next
weekend. Precipitation chances look minimal this upcoming week, with
just a few passing upper waves to tour north.

NMA

&&

.AVIATION...  (For the 18z TAFs through 18z Sunday Afternoon)
Issued at 1142 AM CST Sat Nov 8 2025

A compact storm system over the mid Mississippi Valley will
glide east into central Illinois tonight, bringing mixed
precipitation and lowering both ceilings and visibilities. VFR
ceilings and light, fickle winds will continue through the
afternoon, but as more persistent precipitation arrives this
evening ceilings will lower into the MVFR category. After midnight
tonight, winds will rise sharply and HREF advertises high
confidence (70-90% chances) in IFR ceilings with moderate rain
which may briefly transition to snow - particularly at PIA, BMI,
and CMI where temperatures are more likely to fall below freezing
before precipitation ends. Widespread rain (or rain/snow mix) will
end by 10-12z, but then isolated (20% coverage) snow showers will
continue through the day Sunday with northwest winds gusting over
25 kt at times.


Bumgardner

&&

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

$$