Marine Weather and Tide Forecast for Port Sanilac, MI

AVIATION

VFR conditions will prevail through today under increasing high clouds from the south and a southeasterly wind to around 10 knots.
Clouds lifting northward will be the first signs of the moisture remnants of Isaias. This moisture will eventual lead to rain showers arriving across the southern metro terminals starting around 09Z Sunday morning. Ceilings will lower towards MVFR at the onset of precipitation.

D21/DTW Convection...Very limited potential for thunderstorms as showers arrives Sunday morning. Greater potential will be south of Michigan.

DTW THRESHOLD PROBABILITIES

* Low for thunderstorms Sunday morning.

PREV DISCUSSION
Issued at 324 AM EDT Sat Oct 10 2026

DISCUSSION...

Surface warm front still in the process of lifting across the central portions of lower MI eventually clears to the north by late morning ushering in respectable southerly warm advection. 850mb temps quickly rise into the mid teens C supporting high temps in the mid to upper 70s.

Remnants of Isaias are expected to track along the western spine of the southern Appalachians tonight into Sunday before deflecting into the mid-Atlantic by Sunday night. Locally, the consequence of this more southerly track is the bulk of the northern rain shield holds to our south and east over Ohio/Lake Erie. As such, there has been a notable downward trend in most model QPF towards a more 0.1-0.25" range along the St. Clair-Erie corridor and Ohio border areas- where highest confidence in showers exist. Shower coverage, duration, and QPF decreases further north and west you go outside of Metro Detroit as building western Great Lakes mid-level ridging noses in towards the Saginaw Bay Sunday. Rain chances come to an end by Sunday evening as the system shifts east of the Appalachians.

Dry, very mild conditions remain in place for Monday as mid-level ridging flattens overtop of lower MI. This collapsing ridge allows the core of the upper Midwest airmass to fold into the area bringing 850mb temps towards the upper teens C leading to widespread 70s with a shot at some seeing 80. A shift back to a more typical fall pattern arrives by Monday night-Tuesday as a cold front sagging out of northern Ontario finally reaches/crosses the central Great Lakes.
Upper Plains mid-level shortwave rides along this frontal boundary as it crosses supporting the region's next chances for scattered showers. Post-frontal airmass marks the return of average temperatures with mid/late week highs in the lower 60s and overnight lows in the lower 40s.

MARINE...

The combination of high pressure over New England and the approaching remnants from Hurricane Isaias will work to strengthening the pressure gradient across the Great Lakes today.
This will bring breezy southeast flow with gusts ranging between 20 to 25 knots through south and central Lake Huron, sporadically peaking around 30 knots over north-central Lake Huron where the fetch is more favorable. Small Craft Advisories are now in place from Port Austin to Port Sanilac given increasing wave heights building in by the late morning hours. Sporadic gust to gales will be possible across north-central Lake Huron, however, confidence in achieving gales will be very low noting high stability over the lakes which will greatly hamper or nullify any mixing of stronger winds aloft.

Breezy conditions will subside through tomorrow as a ridge of high pressure briefly fills in. Remnant moisture from the tropical system will also bring the chance for rain showers. Otherwise, on and off rain showers and some low-end storm chances will be possible through next week as a couple of systems moves through.

DTX WATCHES/WARNINGS/ADVISORIES
MI...None.
Lake Huron...Small Craft Advisory until 4 AM EDT Sunday for LHZ441-442.

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