Marine Weather and Tide Forecast for Sault Ste. Marie, MI

DISCUSSION
Issued at 350 AM EDT Thu Jun 18 2026

Current radar and satellite shows widespread stratiform rain and patchy fog as a 991 mb surface low tracks across northern lower MI. In the upper levels, a larger closed low continues to spin over south central CAN with a piece of energy extending southward over MI. This upper wave and surface low will continue eastward and exit the area later this morning. The gradual exit will eventually usher in drier air in the mid to upper levels, however deep moisture will linger for much of the first half of the day. Widespread stratiform rain will lessen through the morning as larger scale forcing leaves, however weak instability will remain present through the afternoon hours. Decent low level lapse rates will allow for pulse type convection mid day through the afternoon hours, however model soundings depict a quick stop to vertical ascent with the EL just above 700mbs.
Around 15 to 25 knots of shear will exist in this layer, which should be enough to help a couple showers become a little stronger. The main hazards with the strongest storms will be small hail (low chances of an inch or greater), brief heavy rain, and gusty outflow winds.

Widespread patches of northern lower MI have seen 0.5 to +1 inches of rain in the last 24 hours. Missaukee and Roscommon counties have seen some of the most (at least one narrow swath approaching 2 inches). Although this rainfall has been gradual, it is saturating soils. If thunderstorms bring heavy rains to these areas this afternoon, localized ponding in low spots and along creeks/rivers could be seen. Chances remain low at this time for additional thunderstorm development this afternoon in this area.

With higher low level lapse rates, winds of 20 to 30 mph will mix down to the surface this morning through the afternoon hours. These gusts have resulting in hazardous seas (small crafts) over the near shore waters, as well as hazardous swim conditions for Manistee, Alpena, Alcona, and Iosco counties which will likely see 3 to 5 ft waves and a higher chance of ripe currents. Temperatures will remain below normal today.

Chances for weak showers and a storm or two continue into the evening/overnight hours tonight as a weak upper level shortwave moves overhead.

The upper level closed low continues to be anchored over south central CAN through the weekend. This will result in upper shortwaves rotating over MN/WI towards MI, bringing weak shower/storm chances Friday and Saturday. Sunday, guidance drops the larger upper low over MI. Continued rain chances and below normal temperatures through early next week as the upper closed low exits.

AVIATION /12Z TAFS THROUGH 12Z FRIDAY/
Issued at 705 AM EDT Thu Jun 18 2026

LIFR and IFR galore this morning owing to lingering SHRA, BR, and FG. Anticipate CIGs to rise MVFR through the morning with continued SHRA lingering. By late afternoon, VFR to prevail, and should continue through the overnight, barring a high based SHRA passes over a TAF site in NW lower Michigan late this evening. Light winds will quickly become gusty this morning into the afternoon, with WNW to NW winds 10-15kts, some 20-25kt gusts possible. Winds taper later this evening into tonight.

APX WATCHES/WARNINGS/ADVISORIES
MI...Beach Hazards Statement until 4 PM EDT this afternoon for MIZ024-030-031-036.
MARINE...Small Craft Advisory from 2 PM this afternoon to 8 PM EDT this evening for LHZ345-347.
Small Craft Advisory until 8 PM EDT this evening for LHZ348- 349.
Small Craft Advisory until 6 PM EDT this evening for LMZ323- 342.
Small Craft Advisory until 4 PM EDT this afternoon for LMZ344>346.
Small Craft Advisory from 2 PM this afternoon to 8 PM EDT this evening for LSZ321-322.