textproduct: Marquette

KEY MESSAGES

- Strong winds and high waves over eastern Lake Superior are creating dangerous rip currents and swimming conditions along the beaches of Marquette County eastward today; a Beach Hazard Statement is in effect.

- Spotty light lake effect rain showers/sprinkles are possible over the east half today.

- Seasonable temperatures are expected through the week with the exception of slightly below normal temperatures today and tonight.

DISCUSSION

Issued at 235 AM EDT Sun Aug 23 2026

With cold air advection from Canada bringing delta-Ts into the mid- teens Celsius today, expect lake effect cloud cover and rain showers to develop over the eastern half of the U.P. as stout high pressure moves in from the west with time. While the cooler air moving in from Canada today will keep highs a little bit lower than yesterday, temperatures should still get up into at least the 60s across the area with the south central potentially getting up to around 70F. The cold air advection will work to create strong winds and high, short-period waves over southeastern Lake Superior today. Thus, expect dangerous rip currents and waves along the nearshores from Marquette County eastward today; stay safe and out of the water today as the swimming conditions are potentially life-threatening!

While the high pressure moving in will bring an end to the lake effect rain showers/sprinkles over the east half by this evening, with antecedent cooler air still overhead and clear skies tonight, expect low tonight to potentially drop into the 40s to potentially 30s over the interior areas; for some of the colder spots, cannot rule out some patches of frost as we see one of our first tastes of Fall this year.

Expect a return to generally near normal late-Summer temperatures for the rest of this week as a more active period of high pressure ridging followed by a subsequent shortwave low is in store for the rest of the week. Thus, near normal temperatures and dry conditions on Monday give way to slightly above normal temperatures by Tuesday as well as rain showers and thunderstorms, before more normal temperatures are seen over the U.P. once again by the end of the week; another weaker shortwave low may bring additional showers and potentially a thunderstorm over the area behind the main low for the mid-week before drier conditions are seen once again by the end of the week.

AVIATION /06Z TAFS THROUGH 06Z MONDAY/

Issued at 131 AM EDT Sun Aug 23 2026

VFR conditions are expected through the TAF period for CMX and IWD. As temperatures drop aloft lake effect clouds and showers will develop over Lake Superior early this morning, potentially impacting SAW during the morning into the early afternoon. CIGs at SAW will be borderline VFR/MVFR during this time and likely fall to MVFR in any showers that impact the site. Confidence is still low on coverage and timing so kept the mention to a prob30. As mixing increases through the day expect winds to gust as high as 25kt at CMX/SAW from mid morning into the afternoon. The low level will stabilize around sunset with wind falling below 10tk.

MARINE

Issued at 235 AM EDT Sun Aug 23 2026

Lake Superior - N to NW winds of 20 to 30 knots continue over the lake today, especially over the east half where a few gale force gusts up to 35 knots could be seen from time to time along the shoreline from Marquette to Grand Marais, Michigan (NBM shows up to 60% chance). As high pressure builds in from the west today into tonight, expect the winds to weaken slightly as they back more towards the NW (20 to 30 knots over the east half). The winds continue to slowly weaken on Monday before dropping to 20 knots or less again by Monday evening. With a Clipper low approaching for the mid-week, showers and storms return to Lake Superior by Tuesday afternoon, with winds increasing from the S at 20 to 25 knots over at least the eastern half of the lake by Tuesday night. While the winds weaken to around 20 knots or less by Wednesday, shower and storm chances continue through the mid-week as a weaker shortwave rolls into the region via rotating around the Clipper. As cold air advection behind the Clipper and high pressure ridging return to the area towards the end of the week, expect the winds to pick up from the NW again by Thursday; as of right now, the NBM has around a 50% chance for low-end gales between Stannard Rock and the Marquette County shoreline during the daytime on Thursday. With high pressure ridging returning by Friday, expect light winds of 20 knots or less to return to the lake by then.

Northern Green Bay and Northwestern Lake MI - N to NW winds of 20 to 30 knots continue today via cold air advection moving overhead as high pressure trudges in from the west. While it does take awhile, expect the winds to die down to around 15 knots or less again late on Monday as the high's center passes through the area. However, don't expect the calmer waters to last all that long as a Clipper low approaches the area for the mid-week. Thus, we can expect S winds to gust up to 20 to 25 knots again Tuesday evening and Wednesday as the low approaches. In addition, rain showers and thunderstorms return to the area late Tuesday night and remain until Wednesday evening. While some calmer seas could be seen Wednesday evening, with the cold air advection behind the Clipper moving in on Thursday, expect the winds to pick back up to 15 to 20 knots from the NW again as some showers and storms could be seen once more during the daylight hours. High pressure moving in from the west late this week brings winds back down to 15 knots or less Thursday night into the end of the workweek.

MQT WATCHES/WARNINGS/ADVISORIES

Upper Michigan... Beach Hazards Statement from 8 AM EDT this morning through this evening for MIZ005-006.

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