174
FXUS63 KILX 050311
AFDILX

Area Forecast Discussion...Updated
National Weather Service Lincoln IL
911 PM CST Wed Dec 4 2024

.KEY MESSAGES...

- Northwesterly wind gusts of 45-55mph will occur everywhere
  north of the I-70 corridor through midnight...before the gusts
  slowly decrease to 30-35mph by dawn Thursday.

- The strong winds combined with air temperatures dropping into
  the teens will create frigid wind-chill readings of 5 below to
  10 below zero late tonight into Thursday morning.

&&

.UPDATE...
Issued at 911 PM CST Wed Dec 4 2024

03z/9pm surface analysis shows a strong cold front approaching
the I-70 corridor. A band of light rain showers accompanies the
boundary...with the northern fringe of the showers mixing with
snow as temperatures drop. As the line of showers traversed the
area, mixing of higher momentum air aloft down to the surface
created wind gusts of 45-55mph. Behind the cold front, widespread
wind gusts of 35-45mph are noted and will continue into the
overnight hours. Winds will gradually decrease late with the
latest guidance suggesting gusts down to 30-35mph by dawn. Latest
temperatures range from 20 degrees far northwest at Galesburg to
48 degrees south of the front in Flora. Temps will plunge across
the board overnight with lows bottoming out in the teens. The
resulting wind-chill values will drop into the -5 to -10 degree
range, creating dangerously cold conditions for the morning
commute.

Barnes

&&

.SHORT TERM...  (Through Late Thursday Night)
Issued at 256 PM CST Wed Dec 4 2024

A pre-frontal trough continues to move east through eastern
Illinois this afternoon while the main cold front moves into
northwestern Illinois and will continue to move through the CWA
this evening. West winds have increased with gusts of 25 to 30
already being reported at some sites. Models still show that gusts
up to around 45 mph are still possible this evening, so confidence
is high that this will occur. Therefore, the advisory will
continued.

Dynamics associated with the cold front this evening are
sufficient for rain or snow showers. Some of the dynamics suggest
that some of the showers could be moderate at times. When these
moderate showers are associated with snow, then a brief snow burst
is possible that could, though briefly, quickly reduce
visibilities, especially with winds getting over 40 mph. The
chance of this is quite low, 20-30%, and our confidence level is
low as well since some of the models do not suggest these snow
bursts/snow squalls are possible. If they do occur, then caution
should be used while driving out in rural areas this evening if
you come upon a snow burst. The good thing is this precip will be
brief this evening and any snow accumulations should be minor.

Dry weather is then expected Thur into Thur night as high pressure
builds into the area. This high pressie will be a cold one and
below normal temps area expected tonight through tomorrow night.
The gusty winds tonight/tomorrow morning will combine with the
cold temps to bring wind chills down to below zero across the
entire area. As winds decrease in speed on Thur, wind chills will
improve and not be as cold Thur night.

Auten

.LONG TERM...  (Friday through Next Wednesday)
Issued at 256 PM CST Wed Dec 4 2024

High pressure will slide southeast on Friday and bring the return
of southwesterly winds during the day. However, temps will still
remain below normal and highs are expected to only reach above
freezing in west central IL while around 30 is expected in the
east parts of the CWA. However, waa will continue into the weekend
with normal temps in t he 40s is expected for Sat and above normal
temps in the 50s is expected for Sun and Mon. Another weather
system is expected to move toward the area with more rain and rain
showers Sunday afternoon into the first part of the new week. The
good part is that with the warmer temps, the precip will be all
liquid. Unfortunately, once this system moves through and east of
the area, cooler temps return for Tue and Wed. Currently the
colder air will arrive as the precip is ending, so a mix of rain
and snow is possible on the back edge of the precip as it is
ending. Of course this forecast is far enough away that lots could
change before then.

Auten

&&

.AVIATION...  (For the 00z TAFs through 00z Thursday Evening)
Issued at 551 PM CST Wed Dec 4 2024

2330z obs show a cold front extending from near KORD to just south
of KGBG. Westerly winds ahead of the front are currently gusting
15-25kt: however, immediately behind the boundary winds veer to
northwesterly and are gusting 35-45kt through northwest Illinois
and much of Iowa. This higher momentum air will reach the central
Illinois terminals between 01z and 04z...with strong/gusty winds
expected to persist through midday Thursday before gradually
decreasing to less than 10kt by sunset Thursday. A band of SCT-
BKN VFR cloud cover and showers accompanies the front, with skies
rapidly clearing behind the boundary. Based on radar trends, have
included -SHRA at KPIA through 01z. Further southeast, have opted
to include -SHRA or -SHSN at KBMI/KCMI through late evening...with
flurries or very light snow showers possibly lingering at KCMI
until after midnight. Will need to keep an eye on MVFR ceilings
and snow-showers further north across Minnesota/Wisconsin and far
northern Iowa: however, satellite trends suggest these will
largely remain N/NE of the I-74 corridor.

Barnes

&&

.ILX WATCHES/WARNINGS/ADVISORIES...
Wind Advisory until midnight CST tonight for ILZ027>031-036>038-
040>057-061>063.

&&

$$