863
FXUS63 KIWX 010626
AFDIWX

Area Forecast Discussion
National Weather Service Northern Indiana
126 AM EST Mon Dec 1 2025

.KEY MESSAGES...

- Lake effect snow will continue to slowly taper off through the
  evening.

- A round of accumulating snow (1-4") may create hazardous
  travel conditions Monday night into early Tuesday morning.

- Remaining cold through this week.

&&

.UPDATE...
Issued at 620 PM EST Sun Nov 30 2025

Final burst of lake effect snow within an embedded mesovort is
now shifting south and rapidly weakening. Radar mosaic shows
another modest cellular band upstream but this should rapidly
weaken in the next 1-3 hours as high pressure/subsidence build
into the area. While SCT snow showers may linger for a few hours
after 00Z, the threat of heavy snow is ending and will
therefore allow the warning to expire as planned.

&&

.DISCUSSION...
Issued at 109 PM EST Sun Nov 30 2025

Low level lake aggregate trough will remain active for far northern
IN and southwest MI into early this evening. Lake parameters are
good with 700mb/lake temp differentials into the mid 20s and a
decently moist DGZ on the backside of last night`s low pressure
system. Bouts of moderate to heavy lake effect snow with gusty winds
are expected given the convergence and favorable thermodynamic
profile, though any banding should be transient with embedded
mesovorts possible. Have opted to retain the Winter Storm Warning
through 00z to account for the reductions in visbys and heavier
1"/hr snow rates within any banded elements. Counties bordering the
warning to the south and east could also see some brief impacts with
snow showers this afternoon/evening with accumulations generally
less than an inch. Deeper QG subsidence and backing/diminishing low
level winds arrive tonight which should bring a quick end to
any measurable lake effect snow.

Pattern remains active as a positively tilted upper level trough
tracks east through the region late Monday into Monday night with
another round of snow. A lighter snow this time as better moisture
return is delayed off to the southeast. However, favorable upper
level divergence looks to support a relatively strong mid level fgen
signal over the area, along with a relatively deep and saturated
DGZ. A model consensus favors a couple of inches of snow for most
Monday night, though mesobanding could support localized higher
amounts up to 4 inches with reduced stability noted above the fgen
circulation in model xsections.

Broad troughing looks to linger mid week through next weekend with
below normal temps and periodic precip (mainly snow) chances as
numerous upper level waves take aim on the region. A moisture
starved northern stream shortwave does drop a cold front through
later Wednesday into Thursday morning with its main impact being a
renewed shot of cold air. Additional waves ejecting from the
Intermountain West may have more moisture to work with for
precipitation sometime in the late Friday-next weekend period.

&&

.AVIATION /06Z TAFS THROUGH 06Z TUESDAY/...
Issued at 108 AM EST Mon Dec 1 2025

Fog was forming over much of northeast Indiana. The visibility
at SMD had just dropped to a quarter of a mile at 0615Z. Some
patches of clouds were moving over the area, but expect partly
cloudy skies for the most part the rest of the night. Went with
a TEMPO 1SM BR at FWA for now. Temperatures were really radiating
out and may cause fog to form very rapidly. Otherwise, the fog
will lift by late morning before snow spreads over northern
Indiana including both terminals.

&&

.IWX WATCHES/WARNINGS/ADVISORIES...
IN...None.
OH...None.
MI...None.
MARINE...Small Craft Advisory until 8 AM EST this morning for LMZ043-
     046.

&&

$$

UPDATE...AGD
DISCUSSION...Steinwedel
AVIATION...AGD/Skipper