339
FXUS63 KLOT 101117
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
617 AM CDT Fri Oct 10 2025

.KEY MESSAGES...

- Chance of showers (30%) through this evening with a slight
  chance (20%) for thunder across northwest IL this morning.

&&

.DISCUSSION...
Issued at 227 AM CDT Fri Oct 10 2025

A weakening cold front will approach the area today and move
across the area tonight. A line of showers with a few embedded
thunderstorms that currently extends from southwest WI into
south central IA will move across northwest IL through mid
morning and is expected to slowly dissipate as it spreads across
eastern IL by early afternoon. Best thunder chances, which will
still be quite low, will be across northwest IL this morning and
included slight chance thunder mention for a few hours. Its
possible much of this activity will dissipate by early
afternoon, with perhaps just sprinkles/virga and pops show this
trend downward through the afternoon. There is some potential
for showers to redevelop this evening, mainly south of I-80 and
east of I-57. Current forecast has slight chance pops and
maintained those with this forecast.

Southwest winds will increase after sunrise with gusts possibly
into the 25-30 mph range for a time through early afternoon and
then speeds/gusts may diminish through the afternoon. Winds
will begin to shift westerly this evening and then shift
northerly with the cold front later this evening and overnight.

High temperatures today are tricky. The increasing clouds may
keep temps a bit cooler, perhaps mid 60s across northern IL but
if the clouds are not as thick and/or precip dissipates faster,
this may allow for warmer temperatures, which could warm into
the lower 70s across the southeast third of the cwa. Lows
tonight are also challenging. Despite the cold front, much of
guidance has warmed low temps several degrees for Saturday
morning. Have warmed temps a few degrees from the previous
forecast, but trends will need to be monitored.

Models continue to hint at lake effect rain showers Saturday but
the potential appears to be east of the area Saturday morning
with the best chance, and still very low, midday into Saturday
afternoon. Opted to keep the forecast dry for now.

Another weakening cold front will approach the area Monday and
appears similar to today`s cold front. Increasing cloud cover
with the best chance of showers across northwest IL with a
dissipating trend across the rest of the area. Blended pops are
mainly dry for this time period and maintained a dry forecast.

High pressure then appears to settle across the Great Lakes
region through the middle of next week which should keep the
area in easterly flow and generally dry. cms

&&

.AVIATION /12Z TAFS THROUGH 18Z SATURDAY/...
Issued at 617 AM CDT Fri Oct 10 2025

Key messages:

- Breezy southwest winds today (Gusts up around 20 kt).

- A few isolated to widely scattered showers through early to
  mid afternoon.

- Northerly wind shift with a cold front this evening (likely
  after 02Z).

While no significant weather concerns are anticipated through
the period, there will be a period of breezy southwest winds
through the daylight hours today. Increasingly low-level
moisture on these southwest winds will also continue to help
foster at least some isolated to widely scattered showers today
as a weather disturbance shifts into the western Great Lakes.
In fact, we are already seeing some of these showers move in
across northwestern IL early this morning. A very low (<10%)
chance for an isolated thunderstorm also exists with this
activity. While the chance of any thunder today remains far too
low to include in the TAF, we have opted to include the showers
in a tempo group at the Chicago area terminals from mid morning
through early to mid afternoon hours.

A northerly wind shift is then expected with a cold frontal
passage this evening. In the wake of this front, northerly
winds will persist into Saturday, with directions shifting east
of north during the day. We may also see some lower VFR CIGs
move in over the Chicago area terminals Saturday morning as the
flow comes in off the lake.

KJB

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...None.

&&

$$

Visit us at weather.gov/chicago