338
FXUS63 KIWX 052013
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
313 PM EST Fri Dec 5 2025

.KEY MESSAGES...

- Light lake effect snow and patchy freezing drizzle is
  possible tonight into Saturday morning mainly for locations
  near Lake Michigan. Little to no accumulation is expected.

- Continued cold through the weekend, then even colder Monday
  with highs around 20 and lows in the single digits with wind
  chills dropping to -5 to -10 at times.

- Light snow Saturday night into Sunday, snow amounts 1 to 3
  inches possible. Impacts appear that they will be relatively
  limited.

- A couple more disturbances move through by midweek again
  bringing chances for snowfall and even some rain/freezing
  drizzle at times with moderating temperatures.

&&

.DISCUSSION...
Issued at 248 PM EST Fri Dec 5 2025

A weak disturbance rippling through the quasi-zonal flow aloft
below the arctic low circulation centered over the Hudson Bay
Canada. This will bring some lake effect showers to areas near
Lake Michigan this evening. Some freezing drizzle may mix in
with the warmer air from over the warmer lake waters this
evening before switching over to mostly snow showers overnight
tonight. Accumulations expected will be less than an inch and
impacts will be minor.

Slightly warmer temperatures tomorrow with highs in the lower
30s ahead of a trough axis and associated frontal band that
will move through beginning Saturday evening which will bring
chances across the area for snowfall, there may be a short
period with the onset that some freezing drizzle mixes in before
becoming all snow. With this system we are looking at
accumulations from less than an inch to around 3 inches. The
heavier amounts will be the northwestern portions of the CWA and
on the areas near Lake Michigan.

Another arctic intrusion pushes in on the backside of the
frontal passage and brings very cold temperatures back to the
area with single digit lows expected on both Monday and Tuesday
mornings. Wind chills will also range from the -5 to -10 degree
range with luckily relatively light winds forecasted.

We then have a more northwesterly flow aloft across the area
beginning Monday into the middle of the week which we will see a
parade of clipper type systems that will traverse the region.
This will bring periods of snowfall with even a mix of rainfall
with the slightly warmer (thicker) synoptic heights that will
also bring some warmer conditions with highs right around
freezing to the mid 30s. However, another trough will drop
southward into the region bringing another reinforcing shot of
cold air to the area by Thursday into next weekend with highs
once again in the 20s and lows in the low teens to single digits
by next Saturday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SATURDAY/...
Issued at 1247 PM EST Fri Dec 5 2025

Main challenge focuses on a weak system passing through tonight
which could bring a period of MVFR cigs and maybe some light
snow or even freezing drizzle. Upstream obs in southern MN lean
mainly towards -sn, but there are some pockets of UP or even
"rain" that suggests maybe some mix could occur. While lowering
could be a bit premature, models seems to lean towards
decreasing precip trends as it reaches the area tonight. Opted
to drop KSBN to a prob30 for the FZDZ and SN for now. If
anything occurs it should be fairly brief, but could cause a few
minor issues at KSBN for runways. KFWA should remain south of
the better moisture and lift.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 3 PM EST Saturday for LMZ043.
     Small Craft Advisory until 1 AM EST Saturday for LMZ046.

&&

$$

DISCUSSION...Andersen
AVIATION...Fisher