975
FXUS63 KILX 202346
AFDILX

Area Forecast Discussion...Updated Aviation
National Weather Service Lincoln IL
546 PM CST Mon Jan 20 2025

.KEY MESSAGES...

- Bitterly cold conditions continue through tonight into Tuesday
  morning. Wind chill values will top out 10 to 20 below for most
  of central Illinois with a few spots near I-74 approaching -25
  degrees. A Cold Weather Advisory is in effect.

- A warming trend will kick off midweek with temps near or above
  freezing expected through the weekend.

- Scattered light snow showers or flurries are possible this
  evening and overnight. Most areas will see little if any snow
  accumulations.

- Another front moving through the region Wednesday and Thursday
  could bring minor snow accumulations to portions of central
  Illinois. 90th percentile snow accumulations are under an inch.

&&

.DISCUSSION...
Issued at 135 PM CST Mon Jan 20 2025

BITTERLY COLD TO START THE WEEK...
This afternoon, a strong 1050+mb high is centered over the
Canadian Rockies with ridging extending across the Great Plains
into the lower and mid Mississippi Valley. The center of high
pressure will shift to Kansas City early Tuesday morning with
another bitterly cold morning expected across central Illinois as
a result. Lows tonight into Tuesday morning will dip below zero
for most of central Illinois north of I-70 and low single digits
south. A light northwest wind will persist across central
Illinois just east of the center of high pressure which will
contribute to wind chills of 10 to 20 below across most of
central Illinois with a few spots near the I-74 corridor
approaching 25 below. A Cold Weather Advisory will be in effect
for all of our central/southeast Illinois counties from late this
evening through mid Tuesday afternoon.

A LITTLE BIT OF SNOW POSSIBLE...
Despite the low level ridging in place today, a shortwave trough
is progged to dig across the Great Lakes and Midwest this evening
and overnight. An accompanying push of cold air will help to
steepen low level lapse rates and the upper level forcing may
allow a few light snow showers or flurries to be squeezed out of
the very cold air mass. HREF LPMM indicates a few narrow swaths of
a dusting of snow will be possible through tonight, but most
areas should not see any accumulating snow.

TEMPS MODERATING LATTER HALF OF THE WEEK...
Surface ridge axis will shift to our east along the Ohio Valley
Tuesday night into Wednesday with southwest flow overspreading the
Midwest driving a more moderate air mass back into the area and
allowing temps to return closer to the seasonal norms.
Temperatures in the lower 30s will return to the Illinois River
Valley Wednesday and across most of the remainder of the area
Thursday. A weak cold front will move across central Illinois
Wednesday and Thursday bringing another chance for some light snow
to the area. LREF 90th percentile snow amounts are less than an
inch and forecast soundings show pretty shallow moisture with this
system. PWats are less than a third of an inch near the front.
While the warming trend may be stalled for a day Friday behind the
cold front, another system moving across the Great Lakes next
weekend will allow even warmer air into central Illinois. More
widespread 30s are expected over the weekend with some 40s
possible south of I-72.

Deubelbeiss

&&

.AVIATION...  (For the 00z TAFs through 00z Tuesday Evening)
Issued at 546 PM CST Mon Jan 20 2025

VFR conditions will prevail at all TAF sites next 24hrs. Broken CU
is over the sites this evening and will continue for several more
hours, along with possible snow showers at all sites except SPI.
So, did add prob30 for 2-3hrs for all sites except SPI. Then a
couple of hours after the snow showers end, clouds will become
scattered and remain that way through overnight. Scattered cirrus
is expected tomorrow through the day and then become clear in the
afternoon. Winds will be west to southwesterly this evening, but
then become northwest later this evening around midnight. Winds
will become southwest again tomorrow afternoon. Wind speeds will
be around 10-12kts at all sites through the period.

Auten

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Cold Weather Advisory from 9 PM this evening to 3 PM CST Tuesday
for ILZ027>031-036>038-040>057-061>063-066>068-071>073.

&&

$$