025
FXUS63 KDTX 240705
AFDDTX

Area Forecast Discussion
National Weather Service Detroit/Pontiac MI
305 AM EDT Mon Aug 24 2026

.KEY MESSAGES...

- Slightly cooler than average conditions today with rain chances
persisting in the Thumb this morning.

- Warming trend for the middle of the week with the next chance of
rain coming in the late Wednesday and Thursday period.

- War,er and noticeably more humid conditions for the end of the
week.

&&

.DISCUSSION...

Deep upper level trough will maintain its influence over Southeast
Michigan throughout the day. Combination of warm lake water
temperatures with tight cyclonic flow will continue to bring lake
effect or bay effect rain chances to the Thumb this morning. The
outstanding question is when rain will eventually pull away from
Huron County today. Forecast soundings support a fair amount of
warming in the 3.0 to 6.0 kft agl layer after 15z as lower heights
push eastward. The net result is that higher midlevel stability
working into the top of the mixed layer should cause lake/bay effect
to become more sparse by the afternoon today. Highs today are
expected to be in the middle to upper 70s which is 2 to 4 degrees
below normal.

Surface high pressure will build across the region tonight and
Tuesday. Ideal lat e summer for Tuesday with daytime highs near 80
degrees and dewpoints in the 50s.

Warm front will lift across Lower Michigan Tuesday night and early
Wednesday as broad troughing settles into the upper Midwest. Models
have been very consistent in showing nothing more than a very weak
upper level jet streak. Big picture perspective suggests that
precipitation chances will rely heavily on when direct differential
cyclonic vorticity arrives. This suggests sometime late in the
Wednesday period particularly for areas south of I 69. This looks
good as residual stability and dry air from strong subsidence the
day before will be place Wednesday afternoon. The current forecast
calls for dry or a slight chance in Detroit prior to 00z Thursday.
Models then suggest a good amount of wave dampening which results in
nothing more than a spoke of absolute vorticity early Thursday,
unorganized embedded wave energy late Thursday and early Friday.
Good confidence slightly more humid weather Thursday with dewpoints
then dropping behind a cold front Friday.

Lower confidence exists regarding the forecast next weekend. There
is some global deterministic differences on when the next Pacific
jet packet will push into the Great Lakes region. GFS suggests as
early as Saturday while the ECMWF waits until Sunday. Temperatures
look to be in the 80s next weekend.

&&

.MARINE...

Post-frontal breezy northwest flow will persist as cooler air is
ushered into the Great Lakes. Maintenance of wind gusts on the order
of 20 to 30 knots is expected, along with some isolated gust
potential to 35 knots across central Lake Huron. This higher end
gust potential remains most favorable for the morning and early
afternoon hours. Small Craft Advisories across the Saginaw Bay and
into Port Huron have been extended through this evening.

Lingering rain showers and a very low chance for a waterspout also
continues across Lake Huron, tapering off by the afternoon. High
pressure will then begin building into the Great Lakes late this
evening and will center over the region by tomorrow. Wind speeds
start to diminish tonight as a result, leading to lighter winds
tomorrow.

&&

.PREV DISCUSSION...
Issued at 1216 AM EDT Mon Aug 24 2026

AVIATION...

Colder northwest flow is expected to support few/sct low/mid clouds
through the early morning hours, but should remain predominately VFR
ceilings with scattered showers expected to hold to the east of the
terminal corridor. WNW winds hold around 5 knots before increasing
late morning with gusts to around 25 knots and gradually decreasing
towards the mid-late afternoon. Afternoon cumulus field will be
spread across the terminals late morning into the afternoon and are
forecast to hold aroudn 4-6kft. This evening winds will ease while
holding out of the northwest along with a decreasing cloud trend.

D21/DTW Convection... No thunderstorms expected through the TAF
period.

DTW THRESHOLD PROBABILITIES...

* Moderate for ceiling 5000 feet or today.


&&

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

Lake Huron...Small Craft Advisory until 8 PM EDT this evening for LHZ421-441>443.

     Small Craft Advisory until 4 PM EDT this afternoon for LHZ422.

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

$$

DISCUSSION...CB
MARINE.......CB
AVIATION.....AA


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at www.weather.gov/detroit.