699
FXUS63 KDTX 240910
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
410 AM EST Mon Nov 24 2025

.KEY MESSAGES...

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

- Passage of a strong cold front is on schedule for Wednesday
  morning. Westerly wind gusts could reach 45 mph in the afternoon.

- Lake effect snow showers ramp up Wednesday night through
  Thanksgiving Day and linger into Friday.

&&

.DISCUSSION...

SE Mi is between northern Ontario low pressure and mid Atlantic high
pressure today, a setup that maintains dry and mild weather through
this evening. Steady south wind between these systems is directed
into the Great Lakes which combines with full morning sun to support
another round of above normal temperatures. Guidance highs in the
lower to mid 50s are easily reachable with the chance for a few
upper 50s limited by thickening high clouds this afternoon.

The afternoon high clouds are a precursor to the next precipitation
event that the resident warm air mass ensures will be all rain.
Onset timing is nudged a few hours later into Tuesday morning as
model trends show less aggressive northward moisture transport ahead
of the southern Plains system as it moves into the Ohio valley.
There is agreement across the new 00Z deterministic models on a
solution that kicks the southern Plains system more quickly eastward
resulting in a QPF maximum farther south along the Ohio valley
compared to the last few forecast cycles. The northern flank of the
pattern still brings generous coverage of showers into SE Mi but
with rainfall amounts less than 0.25 inch through the day.

The faster eastward pace of the southern Plains to Ohio valley wave
leads to lower coverage of showers or just patchy drizzle Tuesday
night as mild air remains in place between systems. The focus then
quickly shifts to the northern stream low pressure system that is on
schedule to strengthen considerably in the upper Midwest and
northern Great Lakes by Wednesday morning. Deterministic model
dProg/dT and ensemble mean/spread continue to offer solid confidence
in predictability of the system. There is perhaps just a minor
southward position adjustment on the surface low center while the
timing of the cold front remains nearly through SE Mi by 12z
Wednesday. After a broken line of showers along the front, the
system produces a textbook dry slot and low level thermal trough
across Lower Mi that keeps advisory level wind gusts the primary
concern during Wednesday. Strong downward momentum transport is set
to occur within the increasing wind field as the system deepens
during the day, highlighted by SREF mean model soundings that show
mid 40 knot wind available within the mixed layer Wednesday
afternoon.

Despite the strong westerly wind, temperatures are projected to take
until closer to sunset Wednesday evening to drop enough for an all
snow sounding. Lake effect then continues to ramp up Wednesday night
with potential to affect Thanksgiving Day travel as the wind field
remains easily strong enough for snow showers to make in from the
west and north. The usual bulk parameters governing moisture,
convective depth, and low level convergence will continue to be
monitored for favored SE Mi coverage areas in upcoming forecasts.

&&

.MARINE...

Light to moderate southerly return flow today, allowing for milder
air to move into the region. Wind gusts of 25 knots likely over
central Lake Huron.

Good surge of moisture and low pressure tracking through on Tuesday
will support light winds and rain as the weak low tracks in between
the Central and Eastern Great Lakes.

A vigorous low pressure system deepening over Lake Superior Tuesday
night into Wednesday 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 for a Gale Watch. The peak of the winds looks to
be Wednesday evening, but this will be a long duration of gales over
Lake Huron. 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 1156 PM EST Sun Nov 23 2025

AVIATION...

VFR conditions prevail overnight and early Tuesday as a ridge of
high pressure lifts across the region. Some pockets of thicker
cirrus may emerge at times. There remains a lower probability for
patchy ground fog development near sunrise, but confidence in
occurrence remains too low to highlight attm. Cirrus will thicken
with time Tuesday afternoon and evening downstream of a low pressure
system organizing over the midwest. Light northwest wind overnight
becoming southerly and remaining modest Monday.

DTW THRESHOLD PROBABILITIES...

* None


&&

.DTX WATCHES/WARNINGS/ADVISORIES...

MI...None.

Lake Huron...Gale Watch from Wednesday morning through Friday morning for LHZ361-
     362.

     Gale Watch from Wednesday morning through Friday morning for LHZ363-
     421-422-441>443-462>464.

Lake St Clair...Gale Watch from Wednesday morning through late Thursday night for
     LCZ460.

Michigan waters of Lake Erie...Gale Watch from Wednesday morning through late Thursday night for
     LEZ444.

&&

$$

DISCUSSION...BT
MARINE.......SF
AVIATION.....MR


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