A surface trough moving through a very warm and unstable air mass provided the focus for scattered strong to severe thunderstorms over Lake Superior from late evening on the 25th into the early morning of the 26th.

Marine Thunderstorm Wind in SAXON HARBOR WI TO BLACK RIVER MI, LAKE SUPERIOR
From 25-AUG-13 23:00:00 to 25-AUG-13 23:10:00 (EST-5)
Location: SAXON HARBOR WI
Magnitude: 47.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gusts at the Saxon Harbor GLOS station were measured between 45 and 54 mph.

Marine Thunderstorm Wind in SAXON HARBOR WI TO UPPER ENTRANCE OF PORTAGE CANAL MI 5NM OFFSHORE TO US/CANADIAN BORDER INC ISLE ROYAL NP, LAKE SUPERIOR
From 25-AUG-13 23:50:00 to 25-AUG-13 23:55:00 (EST-5)
Location: ONTONAGON
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

Measured wind gust at Western Lake Superior buoy 45006.

Marine Thunderstorm Wind in HURON ISLANDS TO MARQUETTE MI, LAKE SUPERIOR
From 26-AUG-13 01:20:00 to 26-AUG-13 01:30:00 (EST-5)
Location: BIG BAY POINT LIGHT
Magnitude: 40.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gusts at the Big Bay Light GLOS measured between 43 and 46 mph.

Marine Thunderstorm Wind in HURON ISLANDS TO MARQUETTE MI, LAKE SUPERIOR
From 26-AUG-13 02:20:00 to 26-AUG-13 02:25:00 (EST-5)
Location: BIG BAY POINT LIGHT
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Measured wind gust at the Big Bay Light GLOS.

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 26-AUG-13 02:00:00 to 26-AUG-13 02:05:00 (EST-5)
Location: STANNARD ROCK LIGHT
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: C-MAN Station

Measured wind gust at the Stannard Rock C-MAN station.

Marine Thunderstorm Wind in MANITOU ISLAND TO MARQUETTE MI BEYOND 5NM FROM SHORE, LAKE SUPERIOR
From 26-AUG-13 01:20:00 to 26-AUG-13 02:20:00 (EST-5)
Location: MARQUETTE
Magnitude: 45.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gusts at Granite Island Light measured near or over 50 mph through the period.

Marine Thunderstorm Wind in MARQUETTE TO MUNISING MI, LAKE SUPERIOR
From 26-AUG-13 03:03:00 to 26-AUG-13 03:08:00 (EST-5)
Location: MUNISING
Magnitude: 36.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Measured wind gust at the Munising ASOS.

Marine Thunderstorm Wind in MUNISING TO GRAND MARAIS MI, LAKE SUPERIOR
From 26-AUG-13 03:03:00 to 26-AUG-13 03:08:00 (EST-5)
Location: GRAND ISLAND HARBOR LIGHT
Magnitude: 36.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Measured wind gust at the Munising ASOS.

Marine Thunderstorm Wind in GRAND MARAIS TO WHITEFISH POINT MI, LAKE SUPERIOR
From 26-AUG-13 03:30:00 to 26-AUG-13 03:40:00 (EST-5)
Location: MUSKALLONGE LAKE STATE PARK
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Trees and power lines were reported down across Northern Luce County including Muskallonge State Park.

Marine Thunderstorm Wind in GRAND MARAIS MI TO WHITEFISH POINT MI 5NM OFFSHORE TO THE US/CANADIAN BORDER, LAKE SUPERIOR
From 26-AUG-13 03:30:00 to 26-AUG-13 03:40:00 (EST-5)
Location: GRAND MARAIS
Magnitude: 56.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

Trees and power lines were reported down across Northern Luce County including Muskallonge State Park.