A cold front moving through a moist, unstable and strongly sheared environment produced strong to severe thunderstorms over portions of Lake Superior late evening on the 18th into the early morning of the 19th.

Marine Thunderstorm Wind in SAXON HARBOR WI TO BLACK RIVER MI, LAKE SUPERIOR
From 18-JUL-20 21:49:00 to 18-JUL-20 22:00:00 (EST-5)
Location: BLACK RIVER HARBOR
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

There was a tree reported down near the Gogebic County Airport in Ironwood from thunderstorm winds.  The AWOS at the airport also measured a thunderstorm wind gust to 56 mph.

Marine Thunderstorm Wind in PORTAGE LAKE TO HURON IS MI TO LOWER ENTRANCE OF PORTAGE CANAL TO HURON IS INC KEWEENAW AND HURON BAYS, LAKE SUPERIOR
From 18-JUL-20 23:42:00 to 18-JUL-20 23:52:00 (EST-5)
Location: ROCK BEACH POINT
Magnitude: 82.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

There was a public report of a roof blown off a house and numerous large trees snapped off or uprooted in Pequaming.

Marine Thunderstorm Wind in PORTAGE LAKE TO HURON IS MI TO LOWER ENTRANCE OF PORTAGE CANAL TO HURON IS INC KEWEENAW AND HURON BAYS, LAKE SUPERIOR
From 18-JUL-20 23:40:00 to 18-JUL-20 23:50:00 (EST-5)
Location: L'ANSE
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Numerous power outages were reported across northwest Baraga County from thunderstorm winds.

Marine Thunderstorm Wind in POINT ISABELLE TO LOWER ENTRANCE OF PORTAGE CANAL MI, LAKE SUPERIOR
From 19-JUL-20 00:10:00 to 19-JUL-20 00:20:00 (EST-5)
Location: TRAVERSE BAY
Magnitude: 37.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured thunderstorm wind gust at the Grand Traverse Bay GLOS station.

Marine Thunderstorm Wind in MANITOU ISLAND TO POINT ISABELLE MI, LAKE SUPERIOR
From 19-JUL-20 00:10:00 to 19-JUL-20 00:20:00 (EST-5)
Location: POINT ISABELLE
Magnitude: 37.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured thunderstorm wind gust at the Grand Traverse Bay GLOS station.

Marine Thunderstorm Wind in MANITOU ISLAND TO MARQUETTE MI AND W OF GRAND MARAIS MI TO US/CANADIAN BORDER BEYOND 5NM OF SHORE, LAKE SUPERIOR
From 19-JUL-20 00:45:00 to 19-JUL-20 00:55:00 (EST-5)
Location: STANNARD ROCK LIGHT
Magnitude: 66.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: C-MAN Station

Peak thunderstorm wind gust measured at the Stannard Rock Light C-MAN station.

Marine Thunderstorm Wind in HURON ISLANDS TO MARQUETTE MI, LAKE SUPERIOR
From 19-JUL-20 00:48:00 to 19-JUL-20 00:53:00 (EST-5)
Location: MARQUETTE LIGHTHOUSE
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There was a public report of a 45 mph thunderstorm wind gust near Trowbridge Park in Marquette.

Marine Thunderstorm Wind in MARQUETTE TO MUNISING MI, LAKE SUPERIOR
From 19-JUL-20 00:48:00 to 19-JUL-20 00:53:00 (EST-5)
Location: MARQUETTE LIGHTHOUSE
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

There was a public report of a 45 mph thunderstorm wind gust near Trowbridge Park in Marquette.

Marine Thunderstorm Wind in GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFFSHORE TO THE US/CANADIAN BORDER, LAKE SUPERIOR
From 19-JUL-20 02:51:00 to 19-JUL-20 02:56:00 (EST-5)
Location: CARIBOU ISLAND
Magnitude: 49.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: C-MAN Station

Delayed report of a thunderstorm wind gust at the Caribou Island C-MAN station.

Marine Thunderstorm Wind in HURON ISLANDS TO MARQUETTE MI, LAKE SUPERIOR
From 19-JUL-20 00:30:00 to 19-JUL-20 01:00:00 (EST-5)
Location: BIG BAY POINT LIGHT
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured peak thunderstorm wind gusts for the period at the Big Bay Light GLOS station.

Marine Thunderstorm Wind in ONTONAGON TO UPPER ENTRANCE OF PORTAGE CANAL MI, LAKE SUPERIOR
From 18-JUL-20 23:10:00 to 18-JUL-20 23:20:00 (EST-5)
Location: ONTONAGON LIGHT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Widespread power outages were reported from thunderstorm winds across Ontonagon County, especially from White Pine northeast to Ontonagon.

Marine Thunderstorm Wind in BLACK RIVER TO ONTONAGON MI, LAKE SUPERIOR
From 18-JUL-20 23:10:00 to 18-JUL-20 23:20:00 (EST-5)
Location: ONTONAGON LIGHT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Utility Company

Widespread power outages were reported from thunderstorm winds across Ontonagon County, especially from White Pine northeast to Ontonagon.