Marine Weather and Tide Forecast for Marine City, MI

AVIATION

Post-frontal mid-cloud deck continues to spill into Lower Michigan, expanding southward from the Upper Midwest and offering low-end chances for precipitation. A few light showers (and brief MVFR ceilings) are possible, mainly for mbS, late tonight into Wednesday morning, but less favorable moisture profiles preclude any -RA mentions for the rest of the terminal airspace. Ceilings are expected to remain VFR on Wednesday with a 4-5 kft AGL SCT-BKN diurnal cumuliform deck developing during the midday hours.
Increasing stability throughout the day eventually dries out the column leading to SKC by nightfall. Winds largely hold from the north tonight and Wednesday, veering slightly more east of north toward the end of the TAF cycle.

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

DTW THRESHOLD PROBABILITIES...

* Low in ceiling at or below 5000 ft Wednesday afternoon.

PREV DISCUSSION
Issued at 303 PM EDT Tue Oct 14 2025

DISCUSSION...

Expansive sfc high pressure centered over the Minnesota boundary waters region will drift east to Lake Superior by Wed morning. This will sustain a feed of low level dry air across Se Mi within persistent north-northeast winds. Ongoing mid level moisture convergence is however resulting in an expanding area of rain across the upper Midwest. The ageostrophic response associated with an upper jet streak interacting with the mid tropospheric front is driving this region of forcing. Recent adjustments among the 12Z hi res guidance suggests the higher based frontogenetical forcing will track across the Saginaw Valley and thumb region during the first half of the night, with the frontal forcing becoming more focused farther south late tonight through daybreak Wednesday. The very elevated and somewhat brief duration of the better forcing will be offset by the formidable layer of dry air in the low levels. These factors, with support of latest probabilistic guidance, warrants low chance pops tonight with QPF ranging from a trace to a few hundredths of an inch at best.

High pressure will gradually expand across Lower Mi Wednesday into Thursday as high amplitude ridging builds across the western Great Lakes. Expansive clouds are expected Wednesday morning, both a result of mid/high level clouds associated with the elevated frontal system and some lower clouds resulting from the moisture flux off Lake Huron. Deep layer dry air advection through the afternoon will clear skies out by late day. This will at least open the door to some late day diurnal mixing, allowing temps to rebound into the low 60s after early morning readings in the 40s. Optimal radiational cooling conditions Wed night/Thurs morning will support low temps in the 30s outside the metro Detroit heat island (40s in Detroit).
Sunny and seasonally cool temps will prevail through Thursday with the sfc high overhead.

Amplification of the long wave trough over the Upper Midwest is forecast Friday into Saturday. This will force deep layer southwest flow to take hold across Lower Mi, advecting a warmer and more moisture laden airmass into the forecast area. The Medium range model suite all suggest additional amplification within the base of the long wave trough over the Ohio Valley during the latter half of the weekend. The has the potential to be a stronger and more dynamic system, potentially bringing a more widespread region of rain to the forecast area. At this stage in the forecast, there is still ample variability on timing and strength. Generally mild with high rain chances will remain warranted through the weekend at this time.

MARINE...

A cold front will move across the Great Lakes late tonight through tomorrow morning which will veer wind direction from northwest to northeast. Sustained winds around 20 knots with gusts up to 25 knots across Lake Huron will increase wave heights into the outer Saginaw Bay and along the Lake Huron through the morning, where Small Craft Advisories are in place. Rain showers will also be possible with the passage of the front. High pressure will then quickly fill in tomorrow and will hold through Thursday, which will bring light winds and dry weather.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory until 5 PM EDT this afternoon for LHZ421- 441>443.

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