093
FXUS63 KDTX 071910
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
310 PM EDT Tue Oct 7 2025

.KEY MESSAGES...

- Lingering showers over the southernmost areas taper off early this
  evening.

- Cool and dry conditions last through the end of the week.

- Frost is possible Wednesday night and Thursday night.

&&

.DISCUSSION...

Surface cold front is beginning to push south and east of the area
this afternoon with elevated portions of the frontal slope still
lingering south of a Port Huron-Howell line. This supports lingering
scattered light showers/drizzle through the first half of the
evening before the slope fully vacates SE MI. In its wake, strong
high pressure dropping out of northern Canada expands across the
Midwest and Great Lakes. Northerly low level flow along the eastern
flank of the high combined with upper troughing sliding over the
central Great Lakes sets up respectable CAA with local 850mb temps
falling to around 0C (plus or minus a degree) for Wednesday.
Resultant highs only top out in the mid 50s to lower 60s- coolest in
the Thumb, falling short of the mid 60s early October averages.
Cooler airmass will be supportive of moisture flux off Lake Huron
however forecast soundings still suggest only a shallow saturated
layer below the subsidence inversion capping convective depths at
only a few thousand feet, which likely allows stratocu development
over the eastern half of the CWA but should preclude any light
rain/drizzle.

Favorable radiative cooling setup develops overnight Wednesday as
the high center drifts over the lower peninsula promoting clearer
skies and light, if any, winds. With surface dewpoints ranging
between 32-34F, low temps will fall into the mid to lower 30s
(outside of Detroit/immediate lakeshore areas) offering the season`s
first frost chances. Surface ridge axis shifts to the eastern Great
Lakes by Thursday re-establsihing southwest lower level flow and
gradual WAA through the rest of the week. That said, some areas of
frost are possible again overnight Thursday, particularly in the
Thumb, due to another clear, calm night under departing thermal
troughing.

&&

.MARINE...

Post frontal cold air advection brings an uptick in northwest winds
across the area through the afternoon into tonight. Gusts generally
peak around 25 kt over Lake Huron, though some gusts to 30 kt will
be possible across the northern part of the lake this evening. A
Small Craft Advisory remains in effect for the Lake Huron nearshore
waters starting tonight as waves build across the southern basin.
Wind direction veers to north-northeast on Wednesday as a secondary
cold front moves through, maintaining wind speeds in the 10 to 20 kt
range and producing onshore wave activity through the day. High
pressure builds directly into the area Wednesday night and offers
lighter winds and waves through Thursday. Modest southwest wind then
emerges on Friday ahead of the next cold front arriving into the
western Great Lakes.

&&

.PREV DISCUSSION...
Issued at 146 PM EDT Tue Oct 7 2025

AVIATION...

The cold front has pushed through the region currently over TTF at
press time on it`s way out of the state. There is still a band of
light showers and varying cloud heights that will persist a few more
hours with CIGs ranging from IFR to VFR. Will handle with a tempo
before drier air fills in for tonight and may clear out the skies.
There is one additional band of clouds across the UP and WI which
will slide down and may survive the drier air so will keep a mention
of sct clouds around 7kft for a bit tonight before the clear skies
spread across lower MI. Winds have become northerly and will remain
there through the forecast.

For DTW/D21 Convection... Thunderstorms will not occur through the
forecast period.

DTW THRESHOLD PROBABILITIES...

* High for ceiling 5000 ft or less through mid-day, decreasing
  through the afternoon to low by 00z.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Small Craft Advisory from 10 PM this evening to 10 PM EDT Wednesday
     for LHZ421-441>443.

     Small Craft Advisory from 10 PM this evening to 10 AM EDT Wednesday
     for LHZ422.

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

$$

DISCUSSION...KDK
MARINE.......TF
AVIATION.....DRK


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