458
FXUS63 KDTX 232059 CCA
AFDDTX

Area Forecast Discussion...CORRECTED
National Weather Service Detroit/Pontiac MI
359 PM EST Sun Nov 23 2025

.KEY MESSAGES...

- Breezy afternoon conditions ease into the evening.

- Above normal temperatures highlight the early week period along
  with rain showers that move in late Monday night and continue through
  Tuesday and Tuesday night.

- Passage of a strong cold front Wednesday morning. Gusts up to 40
  mph during the day.

- Lake effect snow showers ensue Wednesday night through Thanksgiving
  Day, and possibly into Friday.

&&

.DISCUSSION...

Upper level 120+ knot jet core directly over Michigan this afternoon
will slide east into tonight drawing the low-mid level ridge over
the central/eastern Great Lakes into tonight. This is allowing for
warm advection with 850mb temperatures climbing above 0C. The
result is afternoon highs today that are above normal values. High
pressure will maintain quiet weather conditions through tonight as
overnight lows fall mostly into the upper 20s.

Mild conditions will carry into Monday as warmer S-SW flow remains
in place behind the departing high pressure. Good model agreement
for afternoon high temperatures tomorrow eclipsing 50 degrees for
most of southeast Michigan. Dry air in the lowest 10kft brings only
an increasing coverage of high clouds during the daylight hours.

A closed mid-level low ejects out into the plains today
transitioning to an open wave as it moves towards the southern Great
Lakes in response to a stronger northern stream trough digging into
the northern plains. Associated PV advection and the increase in
deeper moisture with ties to the Gulf will result in increasing
chances for precipitation starting late Monday night/early Tuesday
morning. Lower level dry air will eventually be overcome with the
greatest widespread PoPs generally around 7 am Tuesday as stronger
isentropic ascent arrives. Southeast Michigan will reside in the
warmer airmass Tuesday keeping precipitation type all rain.

The surface low pressure associated with the northern stream trough
is currently forecast to deepen to ~990-991mb per 12Z GFS/ECMWF as
it moves over Lake Superior Wednesday morning. This will bring a
noticeable pattern shift starting with a strong cold front that
surges through Michigan Wednesday morning. A dry slot will bring a
period of lower PoPs Tuesday night ahead of the cold front.
Temperatures will be warm enough for rain p-type with any
precipitation through Tuesday night. Will likely see transition to
melting snow with frontal passage. Post frontal westerly winds will
increase towards wind advisory levels by early Wednesday afternoon.
Winds at 850 mb increase to 45-50 knots around the base of the trough
that move directly over southeast Michigan with increasing low level
lapse rates will support these strong winds. Thermal trough takes
residence over the Great Lakes into the weekend characterized by
850mb temperatures falling to -10C by Wednesday night. This will
easily activate the lakes given the high delta Ts and ramp up lake
effect snow regime Wednesday evening into Thanksgiving. Conditions
should be more than favorable for lake effect to travel into
southeast Michigan. Lake effect may continue into Friday with
additional snowfall potential lurking with a system over the
weekend.

&&

.MARINE...

Northwest winds have peaked this afternoon over the Central Great
Lakes, as ridge of high pressure over the Western Great Lakes
quickly moves in this evening, supporting much lighter winds. Will
allow the Gale warning and small craft advisories to expire on time.

Light to moderate southerly return flow then develops late tonight
into Monday, allowing for milder air to move into the region. Good
surge of moisture and low pressure tracking through on Tuesday will
support widespread rain with light winds.

A vigorous low pressure system tracking through Lake Superior
Tuesday night and into northern Ontario will drag in the coldest air
of the season thus far for the mid week period. Snow squalls and
high end northwest gales appear likely in Wednesday-Thursday in the
time period. Bulk of euro ensembles indicating wind gust speeds of
40-45 knots, thus confidence is high in gales. Gale watches will
likely be issued tomorrow. Winds look to begin to slowly diminish on
Friday as the pressure gradient relaxes, but the cold air (850 MB
temps of negative teens) will continues to support lake effect snow
showers.

&&

.PREV DISCUSSION...
Issued at 1229 PM EST Sun Nov 23 2025

AVIATION...

Gusty post-frontal W to WNW wind to 20-25 kt continues through the
afternoon before diminishing this evening with the loss of daytime
boundary layer mixing and the arrival of ridging associated with
Ohio Valley high pressure. As the ridge axis passes east after
midnight, wind direction backs to southerly before shifting to SSW
at around 10-15 kt for daytime Monday. Prevailing VFR favored
through the period, with mid/high cloud arriving from the upper
Midwest overnight. Can`t rule out some patchy ground fog Monday
morning but the inbound cloud and a weak gradient wind offer very
low confidence and preclude a fog mention in the TAF.

DTW THRESHOLD PROBABILITIES...

* None


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Warning until 4 PM EST this afternoon for LHZ361-362.

     Small Craft Advisory until 10 PM EST this evening for LHZ421-441.

     Small Craft Advisory until 4 PM EST this afternoon for LHZ422-442-
     443.

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

$$

DISCUSSION...AA
MARINE.......SF
AVIATION.....TF


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