St. Ignace, MI 49760 Weather

Key messages

- Some lake induced clouds/showers early today. Slight rain chances for some Sat night/Sunday.

- Cooler today then warming again.

- Better rain threat Monday night and beyond.

Discussion

Issued at 308 AM EDT Fri Oct 30 2026

Cold advection underway on nw low-level flow, ahead of high pressure building into MN/WI. Enough moisture and lake instability on Superior to generate lake effect rain showers into eastern upper MI. Lake clouds have been expanding in northern lower MI, but the moisture depth is shallower, and little if any precip down here.

Upstream high pressure will be over western sections of the forecast by dusk today. Mid-level subsidence and drying will increase today, lowering inversion heights. Sct lake effect rain showers will continue in the eastern UP this morning, mainly early. Those will shut down, though the eastern UP remains on the mostly cloudy side. Northern lower MI will eventually mix out to partly-mostly sunny this afternoon.

High pressure continues toward the Mid-Atlantic coast, where it stalls for a couple day before heading further east. Southerly low-level return flow begins Saturday, and continues until: until something moves in from the west and disrupts it. That won't be until the middle part of next week. However, the tendency for isentropic ascent aloft to generate precip will be fighting off rising heights, at least thru the end of the weekend. By Sunday, a shortwave ridge will arrive overhead. The building ridge should win out, most of the time, in most of the area. However, an isolated shower may be possible Sat night/ Sunday for along the immediate nw lower MI coast, on up across the eastern UP.

Pops do continue to increase for Monday night and beyond. A large cyclone is likely to develop in the lee of the central Rockies, then mature as it ejects toward the northern lakes. This system could well be in a weakening state by the time it actually gets here, but abundant moisture will be pushed north ahead of it.

Temps will be briefly somewhat cooler today, but steadily rebound thru the weekend into early next week. Our next cooldown looks most likely late next week? Maybe? We'll see.

Aviation

Issued at 638 AM EDT Fri Oct 30 2026

MVFR cigs at times this morning at MBL/TVC/PLN, and thru early afternoon at CIU. VFR at APN. Lake effect clouds will diminish with time today, especially in northern lower MI. Otherwise quiet into tonight, as high pressure moves thru. Nw breezes becoming lighter today.

Watches, warnings and advisories

MI: None. MARINE: Small Craft Advisory until 2 PM EDT this afternoon for LHZ346>348. Small Craft Advisory until 2 PM EDT this afternoon for LSZ322. Small Craft Advisory until 8 PM EDT this evening for LSZ321.