Marine Weather and Tide Forecast for Stephenson, MI

SHORT TERM /THROUGH FRIDAY/
Issued at 140 PM EDT Thu Jul 17 2025

Satellite imagery shows a scattered diurnal cu field over the area early this afternoon outside of the areas impacted by the Lake Superior lake breeze (which are cloud-free). While the sunny skies have helped temperatures be a bit warmer in comparison to yesterday, with remnant cool air aloft still leaving the area, highs this afternoon are still projected to only get into the 60s for most of the area, with maybe a spot or two getting to around 70 (such as Iron Mountain). Otherwise, the generally north to northeasterly flow across the area is expected to continue dwindling this afternoon as a weakening omega block moves overhead tonight. With skies remaining clear tonight, expect lows to plummet into the mid 40s in the interior areas.

We see temperatures close to around normal by Friday as warm air advection slowly works its way into the Upper Midwest the rest of today through Friday ahead of an incoming low-level disturbance from the Northern Plains. While shear associated with disturbance looks pretty strong, given that not much CAPE is expected within the atmosphere and the synoptic forcing seems pretty weak, expect only a few showers and maybe an embedded thunderstorm or two to move into the western half of the U.P. by Friday afternoon as the disturbance approaches our area. While cloud cover will build throughout the day, the slight warm air advection should bring high temperatures into the lower 70s across most of the area Friday.

LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/
Issued at 140 PM EDT Thu Jul 17 2025

Rain showers and a few non-severe thunderstorms continue across the area Friday night as the aforementioned disturbance phases with a descending shortwave over northern Ontario and a shortwave moving through the Plains into the Great Lakes. As phasing occurs over the Great Lakes and the low heads towards New England, expect the showers and storms to pull away from the U.P. Saturday, with most of the area becoming dry by late in the morning/early in the afternoon.
While temperatures don't appear to be as cool this weekend in comparison to yesterday, with some Canadian air being brought into the region by a high pressure extending through the Plains and Canadian Prairies, expect temperatures to max-out into the lower 70s Saturday and 70s on Sunday afternoons. With the high projected to move over us the rest of the weekend through early next week, expect conditions to remain dry across the area until the middle of next week; temperatures early next week are expected to be around normal.

While model spread increases by the middle of next week, it does look like our rain chances could increase around the next Tuesday and onward time period as the high pressure leaves to the east and troughing over the central U.S. towards the Upper Midwest. While I'm fairly confident (40-60%) that we will see some rain by the middle of next week given the pattern setup, confidence on the timing of when exactly this happens is next to 0 as it will depend on shortwave energy riding up towards the top of the departing ridge.

AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
Issued at 101 PM EDT Thu Jul 17 2025

As high pressure builds in the rest of today through tonight, expect the winds to slacken as VFR conditions continue through the period.

MARINE
Issued at 259 PM EDT Thu Jul 17 2025

As high pressure continues over us the rest of today through tonight, winds have slackened to 20 knots or less across Lake Superior. Even though we may a couple of shortwaves over the next several days, given that the shortwaves look to be fairly weak, the light winds look to continue over the lake for the rest of this week through the first half of next week. Nevertheless, we could still see showers and a few embedded storms return late Friday through the first half of Saturday, especially near the southern shoreline where more convective potential energy is expected (only a couple hundred J/kg at most though, which is not much). Thunderstorm chances also could appear again by the middle of next week as troughing tries to move in from the Central Plains.

MQT WATCHES/WARNINGS/ADVISORIES
Upper Michigan...
Beach Hazards Statement until 3 PM EDT this afternoon for MIZ005-006.

Lake Superior...
None.
Lake Michigan...
None.