Marine Weather and Tide Forecast for Mackinac Island, MI

DISCUSSION
Issued at 208 PM EDT Sat Oct 17 2026

Pattern Synopsis/Forecast: Mid-upper level heights are in the process of rising this afternoon across the western Great Lakes.
Zonal to weakly ridged upper levels expected across the area through at least the middle of next week. At the surface, expansive high pressure is draped from the eastern Great Lakes south and westward into the central and southern Plains. By later tonight through Sunday, northern MI will lie on the northern periphery of this ~1034mb high pressure that becomes centered to our south over the Ohio Valley. Meanwhile, low pressure is expected to be crossing well to our north across parts of northern Saskatchewan/Manitoba/Hudson Bay. As a result, a tightening pressure gradient is already in the process of ramping up locally, which will remain the case through Sunday and result in renewed breezy to windy conditions. High pressure largely expected to remain in control all the way through the middle of next week before low-end shower chances return toward Thursday of next week as a northern stream system looks to pass by to our north.

Forecast Details: Primary focus this weekend revolves around a return of breezy to gusty winds as northern MI becomes sandwiched between high pressure centered to our south and low pressure crossing well to the north. Winds out of the southwest in the process of ramping up early this afternon, gusting as high as 20-30 mph through the remainder of today, and 25-40 mph at times on Sunday. Sunday's upper end highest gusts likely to occur nearest the Lake Michigan lakeshore of northwest lower into western and central Mackinac County.

A warming trend begins Sunday and continues through much of next week as Pacific-dominant flow pattern should allow temperatures to remain above normal for mid-October. Highs Sunday expected to range from the upper 50s far north and low-mid 60s for northern lower.
Monday through the rest of the week largely in the 60s area-wide, with probabilities increasing for lower 70s across parts of northern lower for Wednesday onward. Next low-end rain chances look to hold off until Thursday as a northern stream wave is progged to pass by to our north, however, latest trends suggest these chances are diminishing as a whole.

AVIATION /00Z TAFS THROUGH 00Z MONDAY/
Issued at 630 PM EDT Sat Oct 17 2026

Winds taper some overnight, but remain persistent out of the SW.
Increasingly zippy flow just off the deck will result in LLWS out of the SW at 2kft... generally 40 to 45kts. SW winds increase further into mid morning hours Sunday, carrying through the remainder of the forecast period. 30 to 35kt+ gusts likely, especially at PLN, CIU, and TVC. Skies to remain mainly clear to outright clear through the forecast period.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...Small Craft Advisory until 5 AM EDT Sunday for LHZ345-346.
Gale Warning from 5 AM to 11 PM EDT Sunday for LHZ345-346.
Small Craft Advisory until 5 AM EDT Monday for LHZ347>349.
Small Craft Advisory until 5 AM EDT Sunday for LMZ323-341-342- 344-345.
Gale Warning from 5 AM to 11 PM EDT Sunday for LMZ323-341-342- 344-345.
Small Craft Advisory until 5 AM EDT Monday for LMZ346.
Small Craft Advisory until 11 PM EDT Sunday for LSZ321-322.