249
FXUS63 KILX 191706
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
1106 AM CST Sun Jan 19 2025

.KEY MESSAGES...

- Cold Weather Advisory is in effect until late Monday morning for
  much of central IL. Bitter cold will last into Tuesday. Wind
  chills below -10 degrees and lows near or below zero are likely
  during this time.

- Dry weather sets up as a high pressure dominates the weather
  pattern for much of the next week.

&&

.UPDATE...
Issued at 1042 AM CST Sun Jan 19 2025

One minor update was made to the forecast on this cold Sunday
morning. Visible satellite imagery shows scattered to widespread
stratocumulus cloud streets streaming from northwest to southeast,
mainly in areas along and north of a Galesburg to Lawrenceville
line. Similar to yesterday, short term model guidance does not
have a good handle on these low clouds. So while guidance suggests
coverage decreasing from west to east in time, opted to be
more pessimistic than guidance in our cloud cover forecast through
mid- afternoon. The BMI airport has been reporting light snow,
and it`s not unreasonable that these cloud streets could squeeze
out a few flurries despite the very cold airmass. Aside from the
BMI observation, have not seen any other evidence of precip
reaching the surface, with no mPING reports and traffic webcams
along the I-74 corridor appearing dry. For now, added a mention of
isolated flurries in our northern counties.

Erwin

&&

.DISCUSSION...
Issued at 250 AM CST Sun Jan 19 2025

Welcome to the deep freeze. Today a high pressure system sets up
over much of the central part of the CONUS and will hang around the
Plains/Midwest through much of the week. A Cold Weather Advisory is
in effect starting at 09z this morning for counties west of the
Illinois River, where wind chills are expected to reach -15 degrees
and colder. Starting at 00z this evening, the Cold Weather Advisory
expands to cover most of the remain counties in the CWA through late
Monday morning.

Highs for today through Tuesday will range from single digits to
upper teens. The coldest temperatures north of I-72 for much of that
period. Lows through Tuesday night will be near or below zero. There
is a 40-70% chance of lows less than -5 degrees Monday morning north
of a Macomb to Bloomington line. Winds out of the NW will be
gusty today (~20-25 knots) increasing wind chills during the
daytime hours west of the Illinois River. Wind chills less than
-10 degrees are likely through Monday night across the CWA. Further
advisory issuances may need to be considered for Monday night,
despite wind chills relaxing during the daytime Monday. Tuesday`s
wind chills could drop below -10 degrees north of I-70, and below -
15 degrees along the I-74 corridor.

Wednesday, temperatures move back into the normal range for this
time of year. Highs warm into the upper 20s to low 30s during the
day Wednesday. For the remainder of the week, it looks like highs
stay in the 30s, possibly warming up into the 40s by next weekend
for some areas. Lows will be in the 20s.

Copple

&&

.AVIATION...  (For the 18z TAFs through 18z Monday Afternoon)
Issued at 1103 AM CST Sun Jan 19 2025

MVFR cloud streets have developed again today, and models once
again have a poor handle on these, making it low confidence as to
how long they will persist. For now, included MVFR ceilings
(either prevailing or tempo) at the I-74 terminals through 20-21z.
A few flurries are possible beneath these cloud streets. Once
these cloud streets dissipate (likely mid to late afternoon), VFR
conditions are expected through the rest of the period. Breezy
northwest winds will gradually weaken after sunset and turn to
westerly by Monday morning.

Erwin

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory until noon CST Monday for ILZ027>030-036-
040.

Cold Weather Advisory from 6 PM this evening to noon CST Monday
for ILZ031-037-038-041>046-048-051>057-061>063-066>068-071>073.

&&

$$