Marine Weather and Tide Forecast for Mackinac Island, MI

SHORT TERM /THROUGH SATURDAY/
Issued at 210 PM EST Fri Dec 12 2025

Currently, surface observations place a stronger cold front near the MN/WI border. Surface gradients have been increasing this afternoon, leading to strengthening southwest winds over Lake MI and northern MI. Radar is hinting at some light snow showers forming just off the coast of Charlevoix and moving into Emmet Co.

Tonight: An approaching system will continue to spread light to moderate snow over northern lower and eastern upper this evening.
Stronger winds aloft and the tighter surface pressure gradient will continue to strengthen winds as they veer westerly. This "punch" of colder air will encompass northern MI by early Saturday morning. Times of moderate and heavy snowfall will be seen initially along the snowbelts, tip of the mitt, northern Lake MI coast, and areas of eastern upper late this evening and tonight. The stronger west to west-northwest winds and colder air during this time will result in powder like snow. This snow has slightly lower SLRs (still a dry snow), but is so fine that visibilities are greatly reduced when it blows around.

Peak snowfall intensity is seen early Saturday for much of NW lower as snow transitions to more of a lake effect footprint, and will continue through the day.

Saturday: Snowfall will become more confined to the northern section of the NW lower snowbelt as winds remain west-northwest. A band of focused snow could form near Little Traverse Bay, resulting in the potential for Emmet and Cheboygan counties to see spots of heavy snow through much of Saturday. Intensity of snowfall over the southern part of NW lower will weaken, but snow should persist.
Around 2 to 6" is expected over the advised areas of northern lower by late Saturday, with locally higher amounts up to +8".

Over eastern upper, heavy snow will likely be confined to northern Chippewa (Whitefish Point and the SOO), with light to moderate times of snow meandering into other parts of Chippewa.
Bands of heavier lake effect snow will begin early Saturday and linger for much of the day, resulting in accumulations of 4 to 8 inches with locally higher amounts of +10" near Whitefish point and near the SOO. Although the snow characteristic will be more of a powder, an ideal environment and some synoptic help will allow for times of snowfall rates of 1-2" per hour under the heavier bands.

Gusty winds and cold temperatures will be present for most of northern MI Saturday, resulting in areas of blowing snow and wind chill values that struggle to rise above 0F the whole day.
See the latest winter weather products for more details.

LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/
Issued at 210 PM EST Fri Dec 12 2025

Late Saturday into Sunday, the upper closed low amplifies west to east and rotates southward over the area. This helps push the final slug of cold air southward. Winds over the CAN shield will turn north-northeast early Sunday. As they do, established lake aggregate troughing over NE Lk Superior will shift over the Whitefish Bay.
With this, heavy snow could be pointed right at the SOO, leading to a 3-6 hour window of 1-2" per hour rates. There is still some uncertainty with the exact time this will occur - Saturday evening or more Saturday night; however the potential remains high for total snow accumulations (Sat & Sun) to reach +8" near the SOO. This will also be a night of very cold temperatures, especially for spots that can see clearer skies overnight (parts of NE lower).

During the day Sunday, winds will veer north and weaken. Potential exists for some areas of LL convergence near Grand Traverse Bay, which could keep areas near, south and west of Grad Traverse Bay snowy most of Sunday.

Another system quickly approaches the area Monday, returning southwest winds and snow chances to most of eastern upper and parts of northern lower. Some brief lake effect snow will be seen late Monday as the system passes. The focus of snow amounts for this system looks to be eastern upper at this time.

Tuesday thru end of period: Temperatures begin to warm Tuesday with breezy southwest winds. Precipitation chances continue for eastern upper late Tuesday into Wednesday, likely in the form of snow up there. Temperatures will warm above freezing beginning mid week, with multiple rounds of precipitation next week as temperatures remain relatively mild.

AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
Issued at 1141 PM EST Fri Dec 12 2025

Lake effect snow will continue to organize through early this morning, with the primary target area centering between taf locations into the northwest lower Michigan snow belts through today. Still expecting to see some lighter snow showers and areas of lower cigs at the taf locations, but thinking vast majority of this time will remain MVFR to lower end VFR. West winds will remain gusty (up and over 25 knots at times), producing some blowing and drifting snow as well. Winds veer northwest this evening, focusing bands of snow across the western taf locations...likely producing periods of IFR conditions.

APX WATCHES/WARNINGS/ADVISORIES
MI...Winter Weather Advisory until 7 PM EST Saturday for MIZ016-017- 020>022-025>028-031-032-099.
Winter Storm Warning until 10 PM EST Saturday for MIZ086-087.
MARINE...Small Craft Advisory until 7 PM EST Saturday for LHZ345>349.
Small Craft Advisory until 7 PM EST Saturday for LMZ323-341- 342-344>346.
Small Craft Advisory until 7 PM EST Saturday for LSZ321-322.