441
FXUS63 KDTX 280957
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
557 AM EDT Tue Jul 28 2026

.KEY MESSAGES...

- Drier and a little cooler weather will dominate the mid week
  period.

- The next chance of showers/thunderstorms is Friday night and
  Saturday.

&&

.AVIATION...

Southward expansion of the cold front has been slower than
anticipated, marked by northwest flow at PTK while light southwest
winds remain over the DTW corridor. The front will settle south
of the state line over the next few hours, drawing the lead plume of
low level moisture with it. A trailing stratus deck has expanded
into most of northern Michigan, and will attempt to push into
northern portions of the airspace this morning before daytime
heating lifts and scatters out the deck. A dry slot in between the
two moisture plumes favors a more aggressive scattering/clearing
trend to support widespread VFR by this afternoon. Otherwise,
northwest flow prevails post-front, sustained around 10-15 knots
through the daytime hours. VFR then prevails overnight.

D21/DTW Convection...No thunderstorms expected through tonight.

.DTW THRESHOLD PROBABILITIES...

* High for ceilings 5000 feet or less this morning. Low by this
  evening.

&&

.PREV DISCUSSION...
Issued at 303 AM EDT Tue Jul 28 2026

DISCUSSION...

A compact mid level short wave along the nose of an upper jet streak
is now exiting to the southeast of the forecast area, taking
lingering showers and scattered thunderstorms with it. Potent mid
level subsidence in its wake will expand across Se Mi during the
course of the morning, reflected in model soundings depiction of a
deepening subsidence inversion. Sfc dewpoints are shown to remain in
the 60s into the afternoon. This will sustain enough low level
moisture to support a fairly healthy stratus/strato cu field today.
There are at least some indications in NAM and HRRR soundings that
some low stratus development in the morning may lend to some
sprinkles or areas of light drizzle before diurnal boundary layer
growth lifts cloud bases. Slight cool air advection within northerly
flow and the cloud cover will warrant highs from the mid 70s to lower
80s today.

A push of low level dry air from the northwest will then commence
this evening and persist into Wednesday as high pressure begins to
expand into the region from the west. This will be in response to
building heights across the upper midwest and Great Lakes region.
Mid level anticyclonic flow and sfc high pressure will sustain dry
conditions into Thursday. The drier air will promote a little better
mixing Wed and Thurs, with the opportunity for decent radiational
cooling, thus leading to greater diurnal spread in temperatures.

Deterministic model solutions show reasonable agreement in
forecasting a deepening of a slow moving mid level wave from the
upper Midwest into the Mid Mississippi/Lower Ohio Valley Friday into
this weekend. The extent to which corresponding mid level troughing,
deep layer moisture and diurnal instability impact Se Mi carries a
little more variability among model ensemble members. Probabilistic
guidance has at least trended a little higher with rain chances
Friday night and Saturday, warranting the chance of
showers/thunderstorms in the forecast.

MARINE...

Low pressure departs the Lake Huron vicinity this morning, dragging
a cold front across the region that allows any convection to taper
off by mid-morning. The low deepens and stalls over the eastern
Great Lakes today as high pressure quickly builds in over the
western Great Lakes. This sets up up a tightened pressure gradient
locally that produces gusty north-northwest wind today, tonight, and
into Wednesday. Winds of 15 to 25 kt will be common, with gusts up
to around 30 kt possible in the southern basin of Lake Huron. Small
Craft Advisories are in effect due to the winds and increasing wave
heights. The high pressure will slowly advance eastward Thursday and
Friday, allowing winds to diminish and ensuring dry conditions. The
weekend presents another window for scattered showers and storms
ahead of the next cold front.

&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement through this evening for MIZ049-055-063.

Lake Huron...Small Craft Advisory until 8 PM EDT Wednesday for LHZ421.

     Small Craft Advisory from 10 AM this morning to 8 PM EDT Wednesday
     for LHZ441>443.

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

$$

AVIATION.....MV
DISCUSSION...SC
MARINE.......TF


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