960
FXUS63 KDTX 061144
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
644 AM EST Sat Dec 6 2025

.KEY MESSAGES...

- Chance (20%) for light snow showers through the morning with very
  low end chance for spotty freezing drizzle. Little to no snow/ice
  accumulation expected.

- Widespread light snow expected Sunday morning into early afternoon.
  Snow accumulations to range between a half-inch to two inches for
  most locations.

- Below normal temperatures continue this week, the coldest of which
  arrive Monday and Tuesday. Wind chill temperatures drop to or below
  zero Monday morning.

- Active weather pattern continues into the midweek period where
  additional snow chances will be possible.

&&

.AVIATION...

Pre-frontal MVFR stratocumulus has settled over the terminals this
morning. A low-end chance remains for some inconsequential light
flurries or perhaps even a touch of freezing drizzle (for the
southern sites) through the morning hours. A cold front is expected
to traverse Lower Michigan today by which the drier post-frontal
airmass could lead to a brief recovery in ceilings, for the evening
hours. Winds generally hold around 10 knots during the day, then
decrease overnight. Ceilings lower to MVFR and possibly down to IFR
tonight as the next system approaches the Great Lakes. Expect
accumulating snowfall to begin early Sunday morning with a
progression to MVFR visibilities. IFR visibilities are possible, but
will depend heavily on the onset timing of snowfall, and when the
peak of the event (higher rates) ensue.

For DTW...MVFR ceilings for most of the day with west winds. Still
can`t rule out a flurry or a few drops of freezing drizzle through
this morning. Snow begins early Sunday morning bringing ceiling and
visibility reductions, likely IFR during the peak, and prior to 16Z.

DTW THRESHOLD PROBABILITIES...

* High for ceiling at or below 5000 ft today and tonight.

* Low in precipitation type as freezing rain through 15Z today, then
  high as snow Sunday morning.

&&

.PREV DISCUSSION...
Issued at 402 AM EST Sat Dec 6 2025

DISCUSSION...

A slow moving cold front will progress across SE MI through the
morning hours which will bring the chance for some isolated to
scattered snow showers. Forcing is relatively weak along the frontal
boundary so snowfall amounts will be generally confined to trace
amounts, up to a dusting. Dry air subsidence will work its way down
along and within the wake of the front which will subtly diminish
the integrity of moisture within the dgz, bringing very low-end
chances for spotty freezing drizzle through the morning. Dry air
advection and enhanced subsidence in the wake of the front will then bring
dry weather for the remainder of the day with temperatures
increasing to around the freezing mark for afternoon highs. Wind
chill temperatures will stay in the 20s given wind gusts peaking
around 15 mph this afternoon.

Attention will then turn to a clipper system set to travel through
the southern Great Lakes and northern Ohio River Valley tomorrow
morning, bringing widespread light snow. Initially, weak system
relative isentropic ascent will commence in the mid- levels early
Sunday morning in anticipation of the approaching system which will
bring the chance for flurries or very light snow for portions of the
cwa. Moist isentropic ascent is then fortified through the southern
half of the cwa favored from 700mb through 500mb which will expand
accumulation snowfall chances from south to north while concurrently
pva increases through the northern-third of the forecast area,
filling in snow chances through the north. This combination will
bring widespread light snow across SE MI with snowfall accumulations
ranging between a half- inch to two inches by the afternoon. Two
caveats for higher end snowfall totals will revolve around any
mesoscale convergent signatures and/or lake enhancement from Lake
Huron.

A subset of hi-res modeling picks up on a brief period of
frontogenetic forcing favored in the late morning to early afternoon
hours that can bring some highly localized enhanced snowfall rates
which would be capable of producing a narrow band with totals
approaching 3 inches. Predictability of this materializing and
potential location of event is low at this time but the greater
potential will be aligned with the better moisture convergence from
I-94 south. Lake convergence over Lake Huron also brings some low end
chances for totals of 2-3" within the northern Thumb, particularly
Huron County. Lake convergent bands are expected to stay offshore,
but some solutions do briefly clip the northern Thumb.

A polar high pressure will then fill in late Sunday into Monday.
Clearing skies, light winds, and snow cover will bring about efficient
radiational cooling Monday morning, dropping lows into the single
digits and wind chills to or below zero. Little relief on Monday as
highs stay capped in the 20s and wind chills returning to the single
digits Tuesday morning. The middle of the week will remain active as
a series of clipper systems again target SE MI. The first will arrive
Tuesday morning, bringing renewed chances for light snow
accumulation. The second clipper system quickly follows up late
Tuesday into Wednesday morning. Ensembles highlight pretty strong
convergence regarding track and intensity of this second clipper
system, with the track moving over Michigan with a strong and quick
upper-level wave accompanying the system. This will bring the likely
chance for widespread wintry precipitation, but favored p-type will
subject the degree or warm air advection downstream of the low. A
wintry mix of rain/snow is favored at this time given modeled thermal
profiles.

MARINE...

Winds will slowly decrease today and veer to the west-northwest as a
cold front washes out over the region. This will lead to light winds
tonight, 15 knots or less. Yet another cold front and surge of cold
air to move in during Sunday, as low pressure tracks through the
northern Ohio Valley. Widespread light snow around Sunday morning
trending toward more localized snow squalls late Sunday as 850 MB
temps lower into the negative mid teens. Northwest winds gusting
between 25-30 knots appear likely late in the day. However, winds
then look to veer to the north-northeast fairly quickly and weaken
Sunday night as high pressure quickly builds in for Monday morning.
None-the-less, large waves of 6+ feet will build over the southern
Lake Huron. Some of these larger waves look to clip the nearshore
waters of Lake Huron as winds veer around, and expect another round
of small craft advisories to be issued.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 AM EST this morning for LHZ421-422-
     441.

Lake St Clair...None.
Michigan waters of Lake Erie...None.
&&

$$

AVIATION.....KGK
DISCUSSION...AM
MARINE.......SF


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