097
FXUS63 KDTX 230854
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
354 AM EST Tue Dec 23 2025

.KEY MESSAGES...

- Dry with temperatures in the 40s today.

- Trends have been cooler for mid to late week, but temperatures
  still look to be slightly above normal.

- The potential exists for a wintry mix, including rain, snow and
  freezing rain impacting the Friday morning commute.

&&

.DISCUSSION...

Wet bulb cooling overnight brought temperatures at the surface down
to 32-34 degrees F early this morning, which should keep better
chances of freezing drizzle at bay for most southeast Michigan
through the remainder of the morning hours. Spotty light
precip/drizzle will continue to be supported through about 7 am.
There remains the possibility for local cool spots to touch just
below freezing, especially across the Irish Hills, allowing for
isolated slick spots caused by patchy drizzle and any residual water
freezing on roadways and sidewalks. Warm advection draws surface
temperatures into the upper 30s and low 40s by mid morning ending any
freezing concerns. Dry air likely to will win out through the
remainder of today. Mixing depths shrink keeping winds in the 15 to
25 mph range with low level jet winds at 30+ knots. The Great Lakes
reside on the periphery of an anomalously warm ridge over the central
CONUS with temperatures at 850mb just above 0C today. A few breaks
in the clouds will be possible today by the afternoon as daytime
highs reach into the low-mid 40s. Forecast soundings point towards
some lingering low level moisture trapped under an inversion, which
may allow for some patchy fog development tonight.

A quick moving mid/upper level shortwave will pass across Ontario to
Quebec tonight and tomorrow and draw in cooler temperatures from the
northeast. This will result in a cool down back into the 30s for
daytime highs Wednesday. Surface high pressure passing through the
central Great Lakes and plenty of dry air in the lowest 10kft will
bring another day without precipitation. Weak, disorganized
shortwave will pass over the ridge and into the Great Lakes
Wednesday night. Moisture will be lacking as entrance region jet
dynamics and nearby frontal slope possibly aides in the generation
of some light precipitation. Latest guidance suggesting nothing more
than a couple hundreths across up to the I-96 corridor, if anything
at all. Forecast surface temperatures currently hover freezing, which
brings at least a low chance for brief period of light mixed
precipitation. Low confidence in any meaningful impacts from this for
Wednesday night.

Trends have been cooling significantly over the last couple forecast
cycles with temperatures on Christmas Day and the day after. An
Ontario high pressure and the associated northerly flow will help
suppress the thermal ridge over the Great Lakes. Highs on Christmas
looking to top out in the mid-upper 30s across the M-59 corridor
with low 40s to the south. Dry conditions expected to prevail by 7 AM
and through the remainder of the day.

Attention turns to the Thursday night and Friday period as a system
organizes along the baroclinic zone with left exit region dyanmics
supporting  widespread precipitation chances. Long range guidance
depicts warm advection aloft with expansion of precipitation that
will overrun a cold surface airmass. The trend towards cooler
temperatures currently has a gradient in surface temperatures of mid
20s across the north to low 30s to the southern border during Friday
morning into Friday afternoon. All precipitation types will be in
play, including a swath of freezing rain, if these temperatures
verify over the course of Friday. Will be monitoring thermal profile
trends as strength of the warm layer aloft and the depth of the
surface cold layer will play key roles in p-type.

&&

.MARINE...

Low pressure to move from west to east across southern Ontario today
which will back wind direction across the Great Lakes from south to
northwest. Widespread light rain/snow will continue through the
morning in response to the approaching low pressure system. Back of
winds to the northwest will allow cold air to briefly fill in over
lake Huron late tonight through Wednesday morning, which will
improve mixing depths and over-lake instability. This will bring
about gusty conditions with gust to gales across northern and north-
central Lake Huron. A Gale Warning is now in effect. Wave height to
build farther south through the outer Saginaw Bay and into the tip
of the Thumb, where Small Craft Advisories are now in place.  High
pressure then quickly builds in through the day tomorrow, rapidly
diminishing stronger gust potential through the later morning hours.

&&

.PREV DISCUSSION...
Issued at 1157 PM EST Mon Dec 22 2025

AVIATION...

Notable increase in lower level moisture early this morning will
translate into some inconsequential very light rain showers or
drizzle. Prospects for freezing rain/drizzle no longer exist with
temperatures still solidly in the middle 30s. An associated
reduction of ceiling height into MVFR expected. Little evidence
upstream for a period of IFR, but will continue to monitor going
forward this morning as low saturation persists into the mid-late
morning period. Modest winds from the south overnight, becoming
southwesterly early Tuesday. Clearing potential increases into the
afternoon as drier air arrives within the immediate wake of a cold
frontal passage. Wind shift to westerly with this frontal passage.

For DTW...A few pockets of very light rain or drizzle remain
possible during the early morning hours. Temperatures will remain
above freezing, so no threat for freezing rain/drizzle.

DTW THRESHOLD PROBABILITIES...

* High in ceilings aob 5000 feet overnight through Tuesday morning.
  Low Tuesday afternoon.


&&

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

     Small Craft Advisory from 10 PM this evening to 10 AM EST Wednesday
     for LHZ421-441-442.

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

$$

DISCUSSION...AA
MARINE.......AM
AVIATION.....MR


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