802
FXUS63 KDTX 011932
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
332 PM EDT Sat Nov 1 2025

.KEY MESSAGES...

- There is a chance for light rain showers to develop today, mainly
between I-94 and I-69.

- Breezy conditions Monday as a cold front crosses the region. There
is a chance that peak gusts may fall into the 35 to 45 MPH range.
Chances for rain favored towards northern half of the region.

&&

.DISCUSSION...

A weak surface low over southern Lake Michigan this morning has been
nearly stationary today with a secondary circulation now seen
drifting slowly eastward along a stalled frontal boundary/surface
convergence boundary. These features have provided enough forcing
with steep, diurnally driven low level lapse to produce some
scattered light showers between I69 and I94 today. This will likely
continue through this evening with little change to the lower level
forcing in the near term. Eventually conditions become less
favorable as the mid-upper level trough that helped spin up these
features becomes more cut off and shunted southward low into the TN
Valley while a surface high expands across the region under a
positively tilted upper level ridge folding into the region. Fair
amount of clouds to start the night should decrease in coverage as
drier air moves in with the ridges so temperatures should have a
chance to drop off later tonight down to around freezing for most
locations. Sunday will be a drier day with ridging still overhead.
Deeper southwesterly flow under increasing midlevel heights and good
deal of sun should help bump up high temps a few degrees into the
mid 50s.

Heading into the new work week, a strong zonal jet aoa 160 knots
will be pushing through the northern tier of the conus and into the
Great Lakes. Bulk of the mid level low forcing looks to curl north
through Ontario while southern portions of the trough swing through
lower MI which will be contending with the ridge holding firm to the
south. Guidance has remained consistent with POPs focusing over the
north half of the CWA early Monday while drier conditions increase
in probability heading south toward the Ohio Border which is
currently positioned more under the right exit region of the jet.
Winds may be the bigger issue Sunday night into Monday as a strong
low level jet around 40-45 knots sweeps over the region ahead of a
front with a tight gradient and 850mb winds still above 35 knots out
of the west behind the front later Monday. Wind gusts of 35 to 45
mph will be possible.

Pattern looks to remain active later into the week and into the
weekend with period rain chances as low amplitude progressive flow
continues across the northern conus. Temperatures will actually
remain fairly consistent though as the low amplitude flow prevents
thermal advection in either direction through the forecast. So highs
hold in the 50s with lows in the 30s to 40s.

&&

.MARINE...

A diffuse high pressure system will hold across the Great Lakes
today which will maintain light winds across the region. There
remains a chance for some isolated light shower development across
Lake Huron through the day and overnight given the weak cold air.
Light winds hold through tomorrow morning but will rapidly increase
through the day ahead of a cold front, which will bring unsettled
conditions across Lake Huron starting late tomorrow night and
lasting through most of the day on Monday. Prior to the passage of
the front, wind direction will back to the southwest through late
tomorrow morning and afternoon, with sustained wind speeds ramping
up to 25-30 knots by late tomorrow night. This also brings
increasingly likely chances for gusts to gales, around 35 knots.
Wind direction will then veer west-northwest on Monday after the
passage of the front, where improved mixing depths will sustain the
chances for gust to gales through the day. A Gale Watch is now in
effect for the Saginaw Bay and greater portion of Lake Huron. Small
Craft Advisories will be likely for zones that are not upgraded to a
Gale Warning. Rain showers will also be likely with the frontal
passage.

A ridge of high pressure will build in Tuesday, bringing respite
from unsettled conditions. A second low pressure system may build
back in on Wednesday, bringing back elevated winds and gusts through
the midweek period.

&&

.PREV DISCUSSION...
Issued at 1237 PM EDT Sat Nov 1 2025

AVIATION...

A compact low pressure circulation near the south end of Lake
Michigan has a surface to mid level front extending eastward roughly
along the I-69 corridor this afternoon. The system is supporting
bands of radar returns that amount to just trace amounts of rain at
the ground due to high cloud base. The diffuse boundary layer
frontal zone is also supporting pockets of MVFR ceiling around FNT
which could expand after sunset while remaining south of MBS and
north of DTW. A short term MVFR mention is maintained in the
forecast while using observations as a guide for later updates on
location and duration as the front dissipates into Sunday morning.
VFR solidifies as southwest flow strengthens ahead of the next
larger low pressure system in central Canada Sunday afternoon.

For DTW/D21 Convection...No thunderstorm activity today through
Sunday.

DTW THRESHOLD PROBABILITIES...

*  Moderate in ceilings aob 5000 feet tonight through to tomorrow.


&&

.DTX WATCHES/WARNINGS/ADVISORIES...
MI...None.
Lake Huron...Gale Watch from Sunday evening through Monday evening for
     LHZ361>363-421-441-462.

     Gale Watch from Sunday evening through Monday morning for LHZ422.

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

$$

DISCUSSION...DRK
MARINE.......AM
AVIATION.....BT


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