278
FXUS63 KDTX 261728
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1228 PM EST Wed Nov 26 2025

.KEY MESSAGES...

- A Wind Advisory is in effect through 4 AM Thursday with sustained
  westerly winds of 20 to 30 mph and gusts to 45 mph.

- Lake effect snow showers increase in coverage and intensity this
afternoon with temperatures falling below freezing this evening.
Highly variable accumulations of a dusting to 2 inches expected by
Thanksgiving morning.

- Wind chills drop into the teens Thursday morning and only increase
into the 20s by Thursday afternoon.

- Snow showers and gusty winds to 40 mph continue through
Thanksgiving Day. Another dusting to 2 inches will be possible,
although the Thumb region will see locally higher amounts.

- Additional chances for accumulating snowfall exist Saturday night
to Sunday.

&&

.AVIATION...

Disorganized light snow/rain shower activity around this afternoon.
Strong southwest winds this afternoon gusting 30-40 knots will veer
around to west this evening and carry through much of the taf
period. Westerly winds will allow for numerous Lake Effect snow
shower activity, but bands look to be transient, and should
constrict in coverage overnight. MVFR cigs through evening hours,
but just enough drying expected late tonight into tomorrow to
support just low VFR/borderline MVFR cigs, outside of any very
nature moisture plumes, which still may be able to touch off some
light snow activity. Low confidence in impacts to taf sites, but did
throw in at least flurries.

For DTW...Disorganized light snow/rain shower activity moves through
late this afternoon, with increasing chance of light accumulating
snow shower activity this evening. Main band is not expected to
persist and should drift south overnight, limiting total
accumulation to half an inch to one inch.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 feet or less today and tonight, medium
  tomorrow.

* Medium for westerly cross wind being met this evening through
  Thursday.

* Moderate for precipitation type as snow by late afternoon then
  high this evening and beyond.

&&

.PREV DISCUSSION...
Issued at 1055 AM EST Wed Nov 26 2025

UPDATE...

Only minor updates to the forecast this morning. The main adjustments
were in the short term PoP trends and to increase the wind gusts this
morning as some wind higher wind observations were being observed.

PREV DISCUSSION...
Issued at 438 AM EST Wed Nov 26 2025

DISCUSSION...

Deepening low pressure, currently analyzed at 998 mb over northern
Wisconsin, is in the process of sending an occluded front across
Lower Michigan. The passage of this front is accompanied by
widespread rain showers, with p-type affirmed by temperatures in the
upper 40s to low 50s across SE Michigan. These will be our high
temperatures of the day, as the front represents the lead edge of a
much colder airmass. For reference, upstream temperatures in WI/IL
are in the mid-30s while the 00z ABR RAOB sampled an 850mb
temperature of -9 C. Once the initial batch of showers tracks
through, should see a relatively dry mid-day period as the dry slot
moves in aloft. Main concerns for the first half of the day are
falling temperatures (10-15 degree temperature drop) and wind
potential, with observations over western Lower Michigan already
reporting 40 mph gusts. A Wind Advisory goes into effect at 10 AM
for all of SE Michigan, with wind gusts ramping up to 45 mph by this
afternoon.

Winds will gradually veer from southwest to westerly throughout the
day, setting up lake moisture flux off of a warm Lake Michigan
(water temperatures of 8-10 C). The moisture flux occurs in the
backdrop of strong dynamics and synoptic moisture as the vertically
stacked low pivots across northern Michigan this afternoon-evening.
This generates a robust lake effect response off of Lake Michigan
for the latter half of the day, with the cyclonic flow around the
low eventually adding in aggregate effects from Lake Superior. The
lake effect plume arrives to the edge of the cwa early this
afternoon, with initial p-type favoring rain or a rain-snow mix. As
the vort max gets closer however, the deeper synoptic moisture taps
into the dendritic growth zone to aid in ice production and allow an
increasing proportion of wet snowflakes to mix in. By mid-afternoon,
air temperatures are forecast to be in the mid-30s with wet bulb
temperatures right around the freezing mark. This generally prevents
snow accumulations during the daylight hours, although a higher
intensity snow shower could accumulate on elevated/grassy surfaces
especially in higher terrain areas (i.e. Irish Hills).

The lake effect plume kicks into full gear this evening, as
temperatures fall within a degree or two of freezing around sunset
and below freezing by midnight. The broad footprint of the wave
suggests widespread coverage of snow showers this evening-overnight,
with any higher intensity bands likely shifting south with time as
winds veer. Gusty winds to 45 mph persist through the overnight as
well, with limited decoupling potential due to the deep cold
advective response. A turbulent cloud layer is likely to disrupt
snow growth processes and shatter any larger snowflakes to keep
ratios in check. This combination of strong winds and variable snow
shower intensity also raises concern for snow squalls this evening
in addition to variable driving conditions for any holiday travel.
Most areas will see snow accumulations anywhere from a dusting to 2
inches by Thanksgiving morning, some of which may fall in a short
duration.

By early Thanksgiving morning, should begin to see a shift in the
character of the lake effect with the loss of the deeper synoptic
support and a transition toward more prominent banding. A couple of
dominant bands appear likely: one that extends from near Traverse
Bay into the Thumb and one toward the I-94 corridor/south,
reflecting the veered northwest profiles. In these areas, similar
impact concerns exist as this evening with wind gusts remaining
elevated in the 35-40 mph range. Resultant wind chills will be in
the teens as overnight lows drop into the upper 20s. Will need to
keep an eye on accumulations across the Thumb region Thanksgiving
Day, as some models are pushing 4 inches by the afternoon.
Elsewhere, another dusting to 2 inches will be possible Thanksgiving
Day although accumulations will be more localized than this evening.

Cyclonic influence wanes through the morning hours Friday, shutting
off the already diminishing lake effect response. Heights rise both
Friday-Saturday before the next low pressure system arrives Saturday
night-Sunday. Forecast models are still projecting the surface low
to track right through lower Michigan, with much of the variance
coming from the magnitude of the warm sector. For now, will continue
to advertise potential for accumulating snow with this system
although there is likely to be a rain-snow mix component for much of
the area. Otherwise, cold temperatures continue through early next
week with daytime highs holding in the upper 20s.

MARINE...

Strong low pressure brings deteriorating marine conditions across
the central Great Lakes today. The center of the system will track
through the Straits near peak strength this evening before
continuing into Ontario/Quebec and pulling an arctic air mass into
the region through the late week. A sharp cold front will sweep
across the region this morning with a long duration of gales
expected through Thursday and into early Friday for some areas. Gale
Warnings are in effect for all marine zones through the period, and
Low Water Advisories are in effect for western Lake Erie and inner
Saginaw Bay during the peak of the event today into tonight.

For Saginaw Bay and central/southern Lake Huron, gales will peak
this afternoon through early Thursday, topping out between 40 and 45
kt. The gales will be from the SW behind the morning cold front,
then gradually veer to W early Thursday and NW Thursday evening.
There is high confidence for gales during this period and low
probability for gusts to storm force.

For Lake St. Clair and western Lake Erie, SW gales are expected in
the wake of the front by late morning, reaching a peak near 40 to 45
kt through the evening and overnight. Wind direction gradually veers
to W on Thursday while gales slowly subside.

For northern Lake Huron, gales will be relatively slower to start
today as a weaker gradient exists with the center of the low passing
in the vicinity. However, wind will quickly ramp up this evening as
the low departs and NW gales of 35 to 40 kt are expected there
through the day Thursday.

Rain showers will change over to snow showers this evening and snow
squalls are likely through Thursday into Thursday night. Gales
gradually subside on Friday but wind remains gusty out of the
northwest with additional snow showers. Winds weaken further on
Saturday as narrow high pressure works in ahead of the next system
set to track through on Sunday. This system will bring widespread
precipitation and likely gusty winds to much of the area.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Wind Advisory until 4 AM EST Thursday for MIZ047>049-053>055-
     060>063-068>070-075-076-082-083.

Lake Huron...Gale Warning until 7 AM EST Friday for LHZ361-362.

     Gale Warning until 10 AM EST Friday for LHZ363-421-422-441>443-
     462>464.

     Low Water Advisory until midnight EST tonight for LHZ422.

Lake St Clair...Gale Warning until 4 AM EST Friday for LCZ460.

Michigan waters of Lake Erie...Gale Warning until 4 AM EST Friday for LEZ444.

     Low Water Advisory until 4 AM EST Friday for LEZ444.

&&

$$

AVIATION.....SF
UPDATE.......AA
DISCUSSION...MV
MARINE.......TF


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