600
FXUS63 KIWX 061949
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
249 PM EST Sat Dec 6 2025

.KEY MESSAGES...

- Highs in the 30s through Wednesday except briefly colder
  Monday and again next Friday and Saturday with highs only in
  the lower 20s. Morning lows on Monday, Tuesday, and next
  Saturday will again dip down into the single digits.

- Snow accumulations of mainly 1-2 inches with a few localized
  areas getting around 3 inches tonight into Sunday afternoon,
  highest totals near Lake Michigan. Limited impacts are expected.

- Several systems will bring snow mixed with rain at times
  through this upcoming week. Impacts should be generally limited.


&&

.DISCUSSION...
Issued at 223 PM EST Sat Dec 6 2025

Tonight, chances for snow showers and light snow will increase
through the evening with a weak clipper type system pushing in
from the west. This will continue and spread eastward through
late tonight and tomorrow morning. By Sunday afternoon we will
see the snowfall for most areas diminishing however there will
still be a chance for lake effect snow showers through Sunday
night. Generally 1 to 2 inches of snowfall accumulations are
expected with this system. A few locations could see up to 3
inches total. Some light drizzle/freezing drizzle mainly as the
onset for precipitation occurs this evening would be possible
but would be very short lived before changing over to flurries
and snow showers. The larger snowfall amounts will be for the
northwestern portions of the CWA and areas near Lake Michigan.
At this time messaging of any hazards such as slick roads would
most likely be best disseminated through an SPS product later
this evening.

Cold air will usher in behind this system beginning Sunday
afternoon and evening and drop temperatures quickly. Overnight
low temperatures on Monday morning will dip down into the single
digits near zero. With relatively light winds the wind chills
will make it feel like 0 to -5 degrees. Highs on Monday will
only get into the low 20s with slightly warmer temperatures
along the Lake Michigan shoreline. Tuesday morning will once
again get down into the single digits however just slightly
warmer than the night before with lows just under the 10
degree mark.

With a quasi-zonal flow aloft a few weak shortwaves make their
way through the region beginning on Tuesday and this will allow
for some warm air to advect northward ahead of the disturbance
bringing a quick moderation in temperatures with highs on
Tuesday getting into the mid 30s. This WAA may present a few
issues for the forecast. The first would be how will the snow on
the ground affect the temperature forecast for both the highs
and lows on Tuesday and Wednesday as the warmer air moving over
the cold snowy ground may become modified at a greater rate than
expected keeping temperatures a tad lower than advertised.
This would also lead to less rain mixing in and more of the
frozen variety, including the increased potential for some freezing
rain especially in the onset of any rainfall. The final issue
would be the potential for development of fog across the area
Tuesday through Wednesday. So we will need to continue to
monitor the forecast for those possibilities as we get closer to
the beginning of the week.

Another couple punches of cold arctic air will push southward
into the region Wednesday through the end of the week into the
weekend. High temperatures by Thursday and Friday will only get
into the 20s and by Saturday only the teens. Lows on Saturday
morning will again drop into the single digits.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1235 PM EST Sat Dec 6 2025

Pocket of clearing impacting KFWA with variable flight
conditions (VFR/MVFR) at this time. This is likely to continue
for a few hours before solid MVFR stratus deck moves in from
the west. KSBN was right on the northern fringe of the break so
a few excursions to VFR are possible for the next hour or 2.

Attention then turns to a weakening system that will move in
late tonight into Sunday. Area of light snow should advance
towards KSBN in the 7-9Z Sun time frame and a few hours later at
KFWA. Greatest flight impacts most likely at KSBN where
IFR/possible LIFR cigs are anticipated. Models vary on how much
impact KFWA may see from this with some suggesting MVFR cigs and
maybe some very light accumulations while others show a brief
period of some mesobanding as the last of the energy fizzles.
Have stayed somewhat conservative there for the time being. Any
precip should taper off near the end of the period at KSBN and
near or just outside of the period at KFWA.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...None.

&&

$$

DISCUSSION...Andersen
AVIATION...Fisher