Cicero, Illinois 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

392
FXUS63 KLOT 182101
AFDLOT

Area Forecast Discussion
National Weather Service Chicago/Romeoville, IL
301 PM CST Thu Dec 18 2025

.KEY MESSAGES...

- Scattered wind-whipped snow showers with reduced visibilities
  and rapidly falling temperatures could lead to some slippery
  travel conditions this evening.

- Wind chills of 0 to 10 below expected Friday morning during
  the typical commute hours (~5-9 AM CST). Patchy slick spots on
  untreated surfaces may also linger into the AM commute.

- The blustery and briefly colder conditions tonight into Friday
  will be followed by variable temperatures, but generally
  above normal, into next week.

&&

.DISCUSSION...
Issued at 301 PM CST Thu Dec 18 2025

Through Friday Night:

The main forecast focus and concern is wind-whipped snow showers
and flurries paired with plummeting temperatures this evening
and overnight. This may set the stage for at least patchy slick
spots on some roads as lingering moisture freezes.

Concerns have eased with strong winds with the low topped
strongly forced line of convection out ahead of the cold front,
near/east of I-65 as of this writing. Stratiform rain in the
wake of the cold fro-pa will lag by about an hour or two before
ending. This will be followed by a short lull of 1-3 hours
before snow shower potential ramps up this evening.

Aside from the rain and embedded strong wind trends, the
magnitude of pre-frontal southerly winds has eased just a bit
over northwest Indiana, vs. what was experienced prior to fro-pa
over northern IL.

Westerly winds gusting up to 30-35 mph behind the initial cold
front will very briefly subside (ie. only 5-10 mph winds in RFD
area this hour). Winds will quickly increase again from the
west-northwest as the secondary cold front pushing across the
MS River at this time sweeps across the area through the
evening. Based off upstream observations across eastern Iowa,
expect frequent 35-40 mph gusts through tonight, with
sporadic/occasional gusts around 45 mph.

The cold advection behind the secondary front will be quite
potent (teens into far northern and northwest IA already), owing
to a pocket of nearly -20C air at 850 mb pinwheeling in with the
core of the 500 mb short-wave over the upper MS Valley. Item of
concern here is that the plummeting temperatures will be paired
with scattered snow showers and flurries. Forecast soundings
don`t look classic for snow squalls, but with steep lapse rates
and lift through the DGZ, expectations haven`t changed much
despite the paltry deterministic output.

Relying on upstream radar trends and observations, largely
continued with the idea of mid-high chance range (40-50%) PoPs
peeling southeast with time through this evening and overnight.
It`s possible that the trajectory of more robust snow showers
over central IA focuses them largely south of I-80. However, all
in all, don`t want to rule out the possibility of narrow west-
northwest to east-southeast oriented bands of snow showers
taking shape farther north.

With the above thinking in mind, there may be patchy coatings of
snow and brief sharply reduced visibility underneath any heavier
snow showers amidst general light snow showers and flurries.
With temps falling through the teens and prior rain possibly
washing away some of the road pre-treatments, we`ll continue to
message the potential for localized slick spots developing on
some roads and other paved surfaces. There looks to be enough of
a lag with the stronger cold advection and end of steady rain
this afternoon to preclude a true flash freeze scenario, though
the evening shift will be closely monitoring trends.

Once the snow showers/flurries end for most of the area, there
could be a short-window of lake effect snow showers into
northeast Porter County before that axis shifts east. The bigger
story will be the return to very cold wind chills for the
morning commute. With blustery west-northwest winds only slowly
easing and temperatures in the 10-15F range (localized upper
single digits possible), expect wind chills of around 0 to 10
below. Be sure to dress for the weather if you`ll be spending
time outdoors.

Stratus with some flurries (cloud layer in the DGZ) trapped
under a strong subsidence inversion late tonight may linger
into Friday morning, but substantial low-level dry air advection
should erode clouds from west to east as a surface ridge
crosses the area Friday afternoon. Expect a much colder day on
Friday with highs in the lower to mid 20s. Winds will briefly
diminish to 10-15 mph or less during the mid-late afternoon and
early evening until the next ramp up in winds Friday night. As a
result, only a small drop in temperatures is expected Friday
evening as a 50 knot LLJ spreads over the area and results in
steady WAA through the night.

Castro/Kluber

Saturday through Thursday (Christmas Day):

A low-amplitude wave will then cross far western Ontario on
Saturday. A brief warmup into the 40s is expected early in the
day before temps fall with the passage of a cold front during
the afternoon. Marginal moisture profiles may support a narrow
band of light mixed precip along and slightly behind the front
mainly north of I-80 (kept PoPs under 15% due to modeled very
dry sub-cloud layer). Colder conditions with highs in the mid
20s to around 30F and mostly sunny skies will follow on Sunday
as another high pressure crosses the region.

Moisture return ahead of the next storm system passing well to
the north Monday into Tuesday appears to be insufficient for
widespread precip over the area before a weak cold front passes
on Tuesday. Guidance continues to favor the development of a
broad ridge across the central CONUS by early Christmas.
Expansive WAA with steady low-level moisture advection is
expected across the mid-Mississippi River Valley by Christmas
Eve, with a likely area of stratus and drizzle/light rain in the
region. Placement is still a bit far out to pin point, but a
somewhat damp Christmas Eve into Christmas is possible for
parts of the area. What is of higher confidence is the very mild
temperatures, particularly on Christmas Day when highs may push
60F (!) in spots, especially south of I-80.

Kluber/Castro

&&

.AVIATION /18Z TAFS THROUGH 00Z SATURDAY/...
Issued at 1215 PM CST Thu Dec 18 2025

Key Messages:

- Rain, IFR ceilings, and a gusty westerly wind shift will occur
  early this afternoon as a cold front tracks across the area.

- Blustery westerly winds will persist through tomorrow
  morning.

- Wind-whipped snow showers will produce sub-VFR visibilities
  for a period of time tonight.

- MVFR ceilings will build back into the area this evening and
  continue into tomorrow.


A cold front is tracking from west to east across northern
Illinois early this afternoon. As the front reaches the
terminals, a thin line of strongly-forced showers along the
front will likely knock visibilities down to IFR and cause a
brief period of stronger gusts to be observed. A westerly wind
shift will also occur at this time. Rain will then last for
about an hour or two after the frontal passage before ending.
Ceilings are generally expected to be IFR during this time
before likely becoming VFR for a brief while.

After a brief lull in the precipitation and stronger winds, a
reinforcing cold front will barge through the area this evening,
bringing in stronger westerly gusts that should regularly gust
to around 30-35 kts. Scattered snow showers and MVFR ceilings
will also spread into the area behind this front. The wind-
whipped nature of these snow showers will allow them to easily
knock visibilities below VFR levels, with the most robust
showers likely resulting in IFR visibilities. Rapidly
plummeting temperatures behind the secondary front may allow
for snow to accumulate on most surfaces where it falls
steadiest, but currently not expecting much more than a dusting
to be observed at any of the terminals.

The blustery westerly winds should quickly taper off during the
late morning or early afternoon tomorrow, when a return to VFR
conditions is also expected.

Ogorek

&&

.MARINE...
Issued at 300 PM CST Thu Dec 18 2025

A secondary cold front will move across the southern portions
of Lake Michigan this evening. Westerly winds of 35 to at times
40 kt are expected, and a Gale Warning remains in effect to
cover this. The Gale Warning was extended into/through Friday
morning due to the most recent guidance taking a bit longer to
ease the gale force speeds/gusts. Winds will diminish through
late Friday afternoon as an area of high pressure briefly builds
across the southern portion of Lake Michigan. Gusty southerly
winds will quickly redevelop Friday night ahead of the next cold
front, which will move across the region on Saturday.

Castro/Carlaw

&&

.LOT WATCHES/WARNINGS/ADVISORIES...
IL...None.
IN...None.
LM...Gale Warning until 9 AM CST Friday for Winthrop Harbor IL to
     Gary IN.

     Gale Warning until noon CST Friday for Gary to Burns Harbor IN-
     Burns Harbor to Michigan City IN.

&&

$$

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