Lake Superior, 2025

Marine Thunderstorm Wind in Lake Superior, August 9, 2025

August 9, 2025 · NWS APX · 1 event in 1 county or zone

Very hot weather continued. Upstream convection tracked into the region in the evening, decaying quickly with eastward extent, but did result in some gusty winds at the northwest Lower MI lakeshore and across parts of the EUP.

Where it happened

Every event with a place to put it. Tap one for its entry below.

  • Tornadoes
  • Tropical storms and surge
  • Floods
  • Wind
  • Hail
  • Winter weather
  • Heat and drought
  • Cold
  • Fire, smoke and dust
  • Marine and coastal
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Open the live radar over this ground

The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS APX wrote it up.

Very hot weather continued. Upstream convection tracked into the region in the evening, decaying quickly with eastward extent, but did result in some gusty winds at the northwest Lower MI lakeshore and across parts of the EUP.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Gaylord, MI wrote its last area forecast discussion before the first event at Aug 9, 1:26 PM EST, 5 hours 23 minutes earlier.

Area forecast discussion, Aug 9, 1:26 PM EST, 5 hours 23 minutes before
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Hazardous weather outlook, Aug 9, 1:31 PM EST, 5 hours 18 minutes before
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In the hours before

Local storm report, Aug 9, 5:52 PM EST, 57 minutes before
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Local storm report, Aug 9, 6:03 PM EST, 46 minutes before
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Local storm report, Aug 9, 6:12 PM EST, 37 minutes before
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Special weather statement, Aug 9, 6:12 PM EST, 37 minutes before
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Special weather statement, Aug 9, 6:18 PM EST, 31 minutes before
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Local storm report, Aug 9, 6:30 PM EST, 19 minutes before
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The radar

The NCL Michigan radar (KAPX), 164 km away, was scanning. The volume nearest the first event began at 23:50 UTC.

Open the radar archive at this moment

Event by event

1 marine thunderstorm wind. Local standard time, as filed.

Marine Thunderstorm Wind, St Marys River From Point Iroquois to E Potagannissing Bay

When
August 9, 6:49 PM EST
Where
St Marys River From Point Iroquois to E Potagannissing Bay forecast zone, 6.99 mi ESE of Brimley
Measured
35 kt (40 mph) measured gust
Reported by
Mesonet
Coordinates
46.370, -84.430

Gust to 40mph at MDOT site near Dafter, MI.

What these are

Marine Thunderstorm Wind
Thunderstorm winds of 34 knots or more over coastal or lake waters.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

More

Every storm in Lake Superior in 2025Every state in 2025This day in weather history

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1297451.