Marine Weather and Tide Forecast for Mackinaw City, MI

SHORT TERM /THROUGH MONDAY/
Issued at 202 PM EDT Sun Jun 15 2025

Pattern Synopsis/Forecast: Mid-upper level heights are slowly rising this afternoon across the western Great Lakes. Expansive Canadian- originated surface high pressure is draped over Quebec/Ontario and sagging into the western/northern Great Lakes. Not a whole lot of change to this through the short-term forecast period, although high pressure does slowly begin to become forced east through the day on Monday as energy treks upstream across the northern Plains and upper MS Valley.

Forecast Details: Little in the way of sensible weather anticipated through the remainder of the day across northern Michigan with clouds continue to gradually break up and at least partial sunshine area-wide. Variable cloud cover tonight with lows generally in the 50s. Current expectation is that for any convection well upstream to remain well upstream.

For Monday, variable cloud cover expected once again with most numerous clouds by afternoon favored for northern areas. Suppose it's not out of the realm of possibilities to squeeze out a rogue shower across the U.P. during the day Monday, but think chances are quite low. For northern lower, afternoon cu development should be most numerous over interior areas. Inland penetrating lake breezes may provide the impetus for an isolated shower/storm as afternoon temperatures warm to near the convective temp into the upper 70s and low 80s. That said, chances do look quite low (but not zero) for this given limited deep moisture and any synoptic help still remaining well upstream.

LONG TERM /MONDAY NIGHT THROUGH SUNDAY/
Issued at 202 PM EDT Sun Jun 15 2025

Pattern Forecast: At the start of the period Monday night, northern Michigan is expected to be sandwiched between two areas of active weather -- to our south across parts of the OH/TN/lower MS Valleys and to our west over the upper MS Valley and far western Great Lakes. It'll be the latter of the two with potential to bring some shower/storm activity locally by late Monday night into Tuesday. Beyond that, focus transitions to energy emerging lee of the Rockies Tuesday afternoon before trekking northeastward across the nation's midsection Tuesday night through Wednesday night. Some semblance of active weather may linger locally into Thursday with additional precip chances returning late in the forecast period/next weekend.

Forecast Details: As was alluded to yesterday, PoPs will continue to litter the entirety of the long-term forecast period yielding a rather doom-and-gloom look to the forecast. That said, would expect shower/storm chances to be mixed in amongst plenty of dry time through the week. Only day to be considered one to watch for a potential "washout" would be Wednesday.

By Monday evening, convection is expected to be ongoing upstream -- potentially as close as the central U.P., but more so over the western U.P., northern WI, and arrowhead of MN. Latest trends support some of this activity, albeit in decaying fashion, making a run toward parts of northern MI later Monday night into Tuesday morning with highest chances across eastern upper and far northwest lower. Certainly not sold on this solution panning out given best forcing splitting north and south of northern MI. Any lingering precip activity should be very limited by Tuesday afternoon into Tuesday night. Tuesday's highs favored to top out in the mid-70s far north to the mid/upper 80s in downsloping locales of northeast lower. Higher end of this range dependent on cloud cover, but the potential is certainly there for a hot/humid day.

Best chance for more numerous showers/storms (especially for northern lower) arrives during the day Wednesday as deeper moisture advects north with much more aggressive mid-level wave trekking across the region. Primary severe weather threat continues to be favored to our south with higher end instability really struggling to make it this far north. Latest SPC D4 outlook keeps those 15% severe probabilities on our southern doorstep.

Few showers may linger Thursday as the the primary mid-level wave continues to trek across the region, but with a general drying trend anticipated through the remainder of the work week. Ridging builds next weekend, but with potential for a few additional showers/storms as a shortwave crests that ridge. If long range trends hold, the bigger story may wind up being potential for a stretch of very warm temperatures just beyond the end of the of the forecast period.

AVIATION /00Z TAFS THROUGH 00Z TUESDAY/
Issued at 740 PM EDT Sun Jun 15 2025

VFR conditions are expected through the period with occasional CIGs around BKN-OVC050-100, and higher at times. Winds become more south to southwest on Monday, with lake breeze pushing somewhat inland during the afternoon hours. ISO -SHRA possible Monday afternoon, but not anticipating significant impacts to terminals at this time.

APX WATCHES/WARNINGS/ADVISORIES
MI...None.
MARINE...None.