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FXUS63 KILX 232300
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
500 PM CST Sat Nov 23 2024

.KEY MESSAGES...

- Warm and breezy conditions will be seen on Sunday followed by
  light rain (40-60% chance) late Sunday night into Monday. Total
  precipitation amounts will be light, with totals generally less
  than 0.15".

-  A storm system may bring our next chance for accumulating snow
   Wednesday into Thursday. There are growing concerns that this
   could impact holiday travel.

- Sharply colder temperatures arrive late next week into the start
  of December. Probabilities are high (80-90%) for temperatures to
  be well below normal.

&&

.DISCUSSION...
Issued at 303 PM CST Sat Nov 23 2024

Surface analysis this afternoon shows high pressure centered over
the Deep South with ridging extending northward into the Midwest
states. Winds have swung around to the southwest, which has allowed
low stratus to slowly erode from southwest to northeast over the
last few hours. The line of clearing is positioned from roughly
Beardstown to Shelbyville southward as of 3 pm, with it expected to
continue gradually lifting northward through this evening.
Temperatures have been held down under the stratus/subsidence
inversion with readings as of 3 pm sitting in the upper 30s to low
40s. Where skies clear, temperatures may be able to jump several
degrees before sunset.

Right on the heels of the low stratus, mid-level clouds will spill
over the upper ridge into the Midwest states tonight into Sunday.
Low-level moisture increases later Sunday as strong WAA spreads in
ahead of the next frontal system. Temperatures will briefly warm
as breezy southerly winds drive highs to near 60 degrees on Sunday
and Monday for some. Precipitation chances increase Sunday
evening in the form of light rain/drizzle, with chances continuing
into Monday as the system`s cold front quickly works through the
area. Precipitation amounts look rather light with the NBM
showing only a 10% chance (east of I-55) for 0.25".

Much cooler weather spills in behind the cold front as Canadian
originated high pressure sinks southward into the area Tuesday
morning. Overnight lows Monday night look to drop into the 20s with
daytime highs on Tuesday in the middle 30s to low 40s. Temperatures
look to remain cooler than normal through midweek before turning
sharply colder later in the week/next weekend... more on that below.

Things turn more active by the middle of the week as an upper trough
works into the Middle Mississippi Valley. The latest suite of
deterministic and ensemble guidance have come into somewhat better
agreement that a deepening surface low will lift northeast through
or near the Ohio Valley Wednesday night into Thursday, which would
put most of the forecast area in a favorable location for snow.
Ensemble members continue to show a large range of potential
solutions in respect to snow amounts due to slight variations in the
low track, leading to a relatively low confidence forecast. The
NBM probabilities for seeing at least 1 inch or more of snow is
20% or less north of I-70, with with 23.12Z LREF (GEFS, ENS, GEPS)
advertising a 20-50% chance in this same area. There are growing
concerns that accumulating snow could impact holiday travel in the
Wednesday into Thursday time period.

Sharply colder temperatures fill in behind the midweek system as
deep upper troughing remains anchored over the northeast US allowing
a series of upper disturbances/Alberta Clippers to drive lower
mid-level heights southward through the weekend. There is a
greater than 80% chance that temperatures will be well below
normal for the days following Thanksgiving into the start of
December. Air temperatures next weekend may struggle to warm
above freezing for most, with wind chills in the teens to single
digits. Additional chances for quick hitting snow makers are also
not not out of the question.

NMA

&&

.AVIATION...  (For the 00z TAFs through 00z Sunday Evening)
Issued at 500 PM CST Sat Nov 23 2024

Low clouds have cleared KSPI-KDEC, and should clear the rest of
the central IL terminals over the next couple hours. However, as
winds back southeast overnight, low MVFR ceilings are expected to
expand back northwest toward the area. Low confidence forecast on
how far west these clouds will expand, and for now have the
mention at KBMI-KCMI but will need to watch trends later this
evening for possible further expansion. Southeast winds to
increase by late Sunday morning, gusting near 20 kt at times
through afternoon.

25

&&

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

$$