Sebewaing, Michigan Weather Forecast Discussion

996
FXUS63 KDTX 050356
AFDDTX
Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
1156 PM EDT Thu Sep 4 2025
.KEY MESSAGES...
- Brief warmup on Friday before trending back below normal over the
weekend. Breezy conditions daytime Friday as well with gusts
between 30-40mph.
- A few showers are possible Friday morning, mainly for the Tri-
Cities and Thumb areas.
- Potential exists for isolated to scattered showers Saturday night
into Sunday.
&&
.AVIATION...
Steady increase in southerly flow commences tonight, downstream of
strengthening low pressure lifting into the northern great lakes.
VFR conditions with limited cloud coverage through the early morning
hours as greater low level stability holds. Thickening mid cloud for
the mid-late morning period, as the noted uptick in wind speed off
the surface supports a low level wind shear mention. Brief window
for shower development mainly at MBS during this time. Emerging
gustiness to southwest wind for the afternoon hours, peaking around
30 knots.
For DTW/D21 Convection... No thunderstorms expected through the
period.
THRESHOLD PROBABILITIES...
* Low for cigs at 5000 feet or less Friday.
&&
.PREV DISCUSSION...
Issued at 306 PM EDT Thu Sep 4 2025
DISCUSSION...
Early afternoon mostly sunny skies trend cloudier through the late
afternoon-evening as moisture flux from Lake Michigan arrives over
SE MI enhancing the diurnal cumulus field. Even with the sun, temps
have held a solid 10+ degrees below normal as highs top out in the
mid to upper 60s. The next shortwave, currently seen on visible/WV
satellite over northwestern MN, is set to the reach the western
Great Lakes by late tonight locally resulting in increasing cloud
cover and winds organizing out of the south to start the day Friday.
This low is progged to rapidly mature over northern Lake Michigan
early Friday as a 120+kt jet streak rounds the upper trough with the
favorable left exit region setting up well to our north over the
eastern UP. This in combination with the northeasterly track of the
wave into northern Ontario keeps the bulk of associated showers
north of the CWA Friday morning. Overall running forecast is largely
unchanged with 25-40% PoPs for areas along/north of M-46, though did
extend slight chances (15-20%) down to I-69 given the high-res suite
trying to maintain a shower or two that far south. That said, QPF is
lean as shower intensities remain light. Main impacts with this
system instead are the winds. Southerly winds rapidly strengthen
Friday morning while veering to the west-southwest as a 40-55kt LLJ
expands over southern lower MI. Gusts between 25-35mph are expected
by late morning over the southern half of the region. With the core
of the LLJ passing over the central portions of the lower peninsula,
gusts for the northern half of the CWA (roughly along/north of I-69)
will be able to reach 30-40mph. Winds begin weakening by evening as
low pressure slides into northern Quebec. This strong southerly flow
does bring a brief warm up allowing highs to reach the upper 60s-
lower 70s before the arrival of the cold front Friday afternoon.
Reinforcing shot of cool air follows the front as the parent upper
trough settles over the Great Lakes. 925mb temps slip into the upper
single digits (C) for the weekend and Monday keeping high temps each
day closer to the mid 60s, well below the upper 70s early September
average. Overnight lows fall towards the mid 40s with Sunday night
favored to see low 40s following the passage of another shortwave-
said wave crosses the western/central Great Lakes late Saturday
night-Sunday. This system is weaker than Friday`s however with the
cool airmass in place and warm lake temps, delta-T`s are more than
sufficient to see lake enhancement of accompanying showers which
should support at least widely scattered coverage.
Drier conditions follow for early next week as surface pressure
drifts over the Great Lakes/Ohio valley. Upper trough eventually
retracts back into Canada allowing for moderation in temps back into
the 70s by mid-week.
MARINE...
Winds organize out of the south early Friday morning as the next low
pressure system arrives over northern Lake Michigan. Rapid
maturation of the low leads to a quick tightening of the local
pressure gradient and subsequent uptick in wind strength through the
morning. Sustained winds around 30kts are expected across the bulk
of Lake Huron by mid Friday morning as gusts increase towards 35kts.
Low slides northeast towards northern Ontario through the day while
dragging a cold front across the region resulting in winds shifting
towards the west-southwest by late morning. As this occurs, a 40-
50kt low level jet is set to expand over the central Great Lakes
supporting a further uptick in wind gusts towards 40kts over Lake
Huron. A few gusts approaching 45kts with sustained winds near 34kts
not out of the question for central Lake Huron late morning-early
afternoon (~10a-2p). All of Lake Huron has been upgraded to a Gale
Warning Friday as a result. Lakes St Clair and Erie expected to see
weaker winds given their displacement from the low with gusts
holding more towards the lower 30kt range. Small craft advisories
have been issued for both nearshore waters. With the current wind
forecast, water levels in both the Saginaw Bay and western Lake Erie
near or fall below low water advisory criteria Friday morning. These
trends will be monitored and with issuance of an advisory
potentially needed in coming forecast updates. With a cooler airmass
expanding back over the lakes, waterspouts will again be possible
Friday into this weekend. Cooler, unsettled weather lingers into
early next week as the upper trough settles over the Great Lakes.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...Beach Hazards Statement from 8 AM EDT Friday through Friday evening
     for MIZ049-055-063-083.
Lake Huron...Gale Warning from 4 AM to 10 PM EDT Friday for LHZ361>363-421-422-
     441>443-462>464.
Lake St Clair...Small Craft Advisory from 4 AM to 10 PM EDT Friday for LCZ460.
Michigan waters of Lake Erie...Small Craft Advisory from 4 AM to 10 PM EDT Friday for LEZ444.
&&
$$
AVIATION.....MR
DISCUSSION...KDK
MARINE.......KDK
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at www.weather.gov/detroit.

NWS DTX Office Area Forecast Discussion