518
FXUS63 KLOT 112320
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
520 PM CST Tue Nov 11 2025

.KEY MESSAGES...

- Warming temperatures through the end of the week.

- Next chance for precipitation not expected until early next week.

&&

.DISCUSSION...
Issued at 238 PM CST Tue Nov 11 2025

Through Wednesday night:

A shortwave disturbance continues to dive southward across the
area this afternoon which has generated a few light radar echoes
in north- central IL associated with some virga and flurries.
With cloud bases around 12,000 ft and the very dry sub-cloud
layer don`t expect this virga/flurries to reach the ground as
they progress eastward through early evening so plan on dry
conditions prevailing. That said, southwest winds will continue
to gust around 25-30 mph through sunset which may result in
instances of blowing and drifting snow over the snow pack in
northwest IN and eastern IL. Given the shallow nature of the
blowing snow and the localized threat area we have opted to
handle with a Special Weather Statement and not put blowing snow
into the official forecast just yet. As winds subside after
sunset the threat for blowing/drifting snow will also diminish.

Tonight will feature mostly clear skies and generally light
winds which will allow temperatures to fall into the low to
mid-30s overnight. Though, with a stout 40-45 kt low-level jet
overhead a few isolated 18-20 mph gusts may be seen overnight
especially in the metro where the urban heat island may maintain
mixing. The dry weather will continue into Wednesday as high
pressure builds into the area. Temperatures will rebound
Wednesday afternoon with highs in the lower 50s for most, but
those within the snow pack will likely stay in the upper 40s.
Winds will also become breezy again with westerly 20-25 mph
gusts Wednesday afternoon before gusts subside Wednesday
evening. Temperatures will once again cool into the low to
mid-30s Wednesday night.


Thursday through Tuesday:

High pressure will remain in control of our weather through the
end of the week which will keep rain-free conditions in play.
With continued warm advection and mid-level height rises
temperatures will continue to warm through the week with highs
reaching the mid- 60s to possibly lower 70s by Saturday.

However, a shortwave trough is progged to pivot into the
northern Great Lakes on Saturday which looks to force a cold
front through northern IL and northwest IN Saturday night into
Sunday. Despite the southerly winds prior to the fronts arrival,
moisture return looks to be very limited which should limit
rain chances with the front. That said, forecast soundings do
show some modest moisture to be present so would not be too
surprised to see a stray shower and/or sprinkle Saturday night
into Sunday morning so for now have maintained slight chance
(15-20%) POPs for this period. Regardless of the rain chance,
temperatures are forecast to cool back toward seasonable values
in the upper 40s and lower 50s Sunday into next week.

Our next chance for measurable precipitation is not expected
until the late Monday through Tuesday timeframe as another
shortwave trough ejects out of the southwest CONUS and into the
Great Lakes. While guidance is in decent agreement on this
troughs path, there is a lot of variability on how strong the
trough will be where the associated surface low will track. If
the stronger trough and further south low track materialize then
we could be looking at another period of wintry weather as more
cold air would be funneled into the region, but if the weaker
trough solutions and further north low track come to fruition
then we could be looking at milder temperatures and more rain as
opposed to snow. Given this uncertainty have opted to maintain
the 20-40% POPs offered by the NBM and the all rain forecast,
but will obviously have to keep a close eye on trends as we get
closer.

Yack

&&

.AVIATION /00Z TAFS THROUGH 06Z THURSDAY/...
Issued at 520 PM CST Tue Nov 11 2025

Key messages for the 00Z TAF period:

* Marginal LLWS conditions this evening

W winds this evening will stay up near 10 kt and occasionally
gust to near 20 kt. A low level jet building off the surface
will provide as many as 40 kt of W flow at 2kft AGL. Given the
relatively stronger surface winds expected at the Chicago sites
this evening, opted to omit a LLWS mention in the Chicago TAFs
and maintain a period of LLWS through late evening at RFD, DPA,
and GYY.

Westerly winds tomorrow will gust to between 25 and 30 kt,
possibly higher on occasion, being the strongest during the mid-
late afternoon and subside to around 10 kt for the evening.
Expect VFR throughout the period.

Doom

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Small Craft Advisory until 9 PM CST Wednesday for the IL
     nearshore waters.

     Small Craft Advisory until 3 AM CST Thursday for the IN
     nearshore waters.

&&

$$

Visit us at weather.gov/chicago