458
FXUS63 KDTX 111806
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
106 PM EST Thu Dec 11 2025

.KEY MESSAGES...

- Below normal temperatures resume today and continue Friday.

- Arctic air is further reinforced this weekend resulting in single
digit wind chill Saturday and below zero Saturday night into Sunday
morning.

- A gradual warming trend is projected during the middle of next
week, however it will take until Wednesday for above freezing
daytime temperatures.

&&

.AVIATION...

West surface flow with northwest flow aloft will continue to advect
lake moisture inland, maintaining an extensive strato-cu field along
with flurries through daylight hours. Confidence regarding cloud
trends wane overnight as wind streamlines divert from pure west-
northwest flow, hampering lake moisture advection. The current
thinking is that stratus continues to hold overnight under an
inversion, with lower end probabilities for mvfr cigs as cloud bases
sink. A much lower confidence scenario will be the scouring out of
cloud cover overnight which would then introduce chances of some
freezing fog potential leading to visibility restrictions. The
former has been representing in the ongoing TAFs given the higher
confidence of the maintenance of the stratus deck.

For DTW...Mainly VFR ceilings with flurries. Brief MVFR drops
possible. Max westerly gusts to 20 this afternoon and early evening.

DTW THRESHOLD PROBABILITIES...

*  to high for ceiling at or below 5000 ft through this afternoon,
   moderate this evening and overnight.

&&

.PREV DISCUSSION...
Issued at 827 AM EST Thu Dec 11 2025

UPDATE...

The 12Z DTX sounding had an inversion height up to 5k feet with a
temp around -18C. The heat flux off the lakes has boosted inversions
a little more than previous model solutions suggested. This has
warranting an update to include scattered showers/flurries in the
morning/early afternoon forecast. The low level flow will back more
westerly this afternoon. Losing the Lake Superior connection and
broad large scale subsidence will lower inversion heights, limiting
the coverage of snow showers/flurries later today.

PREV DISCUSSION...
Issued at 352 AM EST Thu Dec 11 2025

DISCUSSION...

The surge of cold air behind yesterday`s low pressure system has
pushed temperatures down into the lower 20s, and into the teens
under pockets of clear sky, across SE Mi this morning as the next
round of colder than normal air builds into the region. The cold air
is reinforced by W-NW flow that continues across the Great Lakes in
the gradient between Plains high pressure and New England low
pressure today and tonight. There is also a weak lake aggregate
trough embedded in this larger scale pressure pattern that serves as
the focus for lake effect snow showers as it wavers from Upper Mi
into northern Lower Mi. The resulting Lake Superior to Lake Michigan
connection is making the most out of an otherwise marginally
supportive larger scale moisture environment. Clusters of snow
showers off the fringes of dominant bands are able to make it down
into the Saginaw Valley and northern Thumb as long as activity
maintains similar strength on radar. Farther south, mid level
subsidence and dry air reduce central and southern Lake Michigan
influence to just clouds and flurries until a narrow ridge of
surface high pressure builds overhead late tonight into Friday
morning.

The new run of 11/00Z hi-res and regional/global models are in good
agreement on maintenance of a northern Plains to Ohio valley low
pressure track through Friday. Models are unanimous in keeping the
northern fringe of snow over northern IN/OH as the lead wave is very
low amplitude. This is followed quickly by a mid level low closing
off from central Canada into the northern Great Lakes Friday night.
It is capable of producing light snow across Lower Mi as it siphons
some higher theta-e air from the central Plains frontal zone into a
weak warm advection pattern ahead of the surface system. Model QPF
averages less than 0.1 inch as 850-700 mb specific humidity
struggles to hold 1-2 g/kg along and ahead of the cold front. This
sets up a higher POP/low accumulation scenario of less than 1 inch
across SE Mi by Saturday morning, subject to some minor upward
adjustment as a potential Lake Michigan lake effect boost comes into
focus.

More important is the surge of arctic air ushered in by the Saturday
morning cold front that entrenches a frigid air mass through the
weekend into early next week. Temperature projections hold readings
in the teens with single digit wind chill Saturday which leads into
single digit low temperatures and sub zero wind chill Saturday
night. A near repeat performance Sunday modifies just a few degrees
warmer by Monday. Temperatures then trend back toward mid December
normals as the 500 mb long wave and upper jet pattern become more
progressive. A building mid level ridge promotes the warming trend,
however daytime guidance temperatures take until Wednesday to
increase above freezing.

MARINE...

High pressure continues building into the region today from the west
while a dome of cold air lingers over the region in the wake of
Wednesday`s low pressure system and cold front. So while the
gradient generally weakens, the cold air aloft will try to get
stronger winds going, but below Gale force. Small Craft Advisories
are now in effect for Outer Saginaw Bay and the nearshore waters of
Lake Huron to account for continued elevated wave heights as a
result of the continued northwesterly flow. Surface ridge slides
over the Great Lakes today and tonight allowing winds to decrease
further while backing to the west. Winds will remain lower into
Friday before the next clipper tracks through Ontario Friday night
into Saturday, pulling an arctic front through the region Friday
night. This cold airmass will again bring increased winds with
sporadic gusts to gales possible over Lake Huron during the weekend
as 850 MB temps plummet to -20 C, supporting snow squalls and
freezing spray as well.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory until 10 PM EST this evening for LHZ421-442.

     Small Craft Advisory until 4 AM EST Friday for LHZ441.

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

$$

AVIATION.....AM
UPDATE.......SC
DISCUSSION...BT
MARINE.......DRK


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