An upper disturbance approaching from the west interacted with a very warm and unstable air mass to produce strong to severe thunderstorms over Lake Superior on the morning of the 21st.

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 21-JUL-16 05:05:00 to 21-JUL-16 05:10:00 (EST-5)
Location: ROCK OF AGES LIGHT
Magnitude: 41.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: C-MAN Station

A peak thunderstorm wind gust of 47 mph was measured at the Rock of Ages Light C-MAN station.

Marine Thunderstorm Wind in MANITOU ISLAND TO POINT ISABELLE MI, LAKE SUPERIOR
From 21-JUL-16 06:40:00 to 21-JUL-16 06:45:00 (EST-5)
Location: POINT ISABELLE
Magnitude: 41.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

There was a peak thunderstorm wind gust of 47 mph at the Grand Traverse Bay GLOS station.

Marine Thunderstorm Wind in POINT ISABELLE TO LOWER ENTRANCE OF PORTAGE CANAL MI, LAKE SUPERIOR
From 21-JUL-16 06:18:00 to 21-JUL-16 06:24:00 (EST-5)
Location: KEWEENAW LOWER ENTRANCE LIGHT
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Social Media

There was a public report of multiple trees down on either side of the Portage Canal near Jacobsville.

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 21-JUL-16 06:30:00 to 21-JUL-16 06:45:00 (EST-5)
Location: KEWEENAW LOWER ENTRANCE LIGHT
Magnitude: 44.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

The peak thunderstorm wind gust at the Keweenaw Bay buoy 45025 was 51 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 21-JUL-16 06:40:00 to 21-JUL-16 06:45:00 (EST-5)
Location: KEWEENAW LOWER ENTRANCE LIGHT
Magnitude: 41.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

The Keweenaw Bay buoy 45025 measured a peak thunderstorm wind gust of 47 mph.

Marine Thunderstorm Wind in HURON ISLANDS TO MARQUETTE MI, LAKE SUPERIOR
From 21-JUL-16 07:20:00 to 21-JUL-16 07:30:00 (EST-5)
Location: GRANITE ISLAND LIGHT
Magnitude: 42.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Granite Island Light GLOS station measured peak thunderstorm wind gusts between 41 and 48 mph during the period.

Marine Thunderstorm Wind in MANITOU ISLAND TO MARQUETTE MI BEYOND 5NM FROM SHORE, LAKE SUPERIOR
From 21-JUL-16 07:20:00 to 21-JUL-16 07:30:00 (EST-5)
Location: MARQUETTE
Magnitude: 42.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Granite Island Light GLOS station measured peak thunderstorm wind gusts between 41 and 48 mph during the period.

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 21-JUL-16 07:20:00 to 21-JUL-16 07:30:00 (EST-5)
Location: MARQUETTE
Magnitude: 42.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The Granite Island Light GLOS station measured peak thunderstorm wind gusts between 41 and 48 mph during the period.

Marine Thunderstorm Wind in MARQUETTE TO MUNISING MI, LAKE SUPERIOR
From 21-JUL-16 07:40:00 to 21-JUL-16 07:45:00 (EST-5)
Location: SHOT POINT
Magnitude: 38.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

There was a peak thunderstorm wind gust of 44 mph at the MDOT mesonet station six miles east of Harvey.

Marine Thunderstorm Wind in SAXON HARBOR WI TO BLACK RIVER MI, LAKE SUPERIOR
From 21-JUL-16 04:51:00 to 21-JUL-16 05:15:00 (EST-5)
Location: LITTLE GIRLS POINT
Magnitude: 55.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

The Gogebic County Sheriff reported several trees down along Lake Road near Little Girls Point.  There was also a peak thunderstorm wind gust of 40 mph reported at Saxon Harbor during the period.

Marine Thunderstorm Wind in BLACK RIVER TO ONTONAGON MI, LAKE SUPERIOR
From 21-JUL-16 05:35:00 to 21-JUL-16 05:42:00 (EST-5)
Location: ONTONAGON LIGHT
Magnitude: 60.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Emergency Manager

The Ontonagon County emergency manager reported dozens of trees down in and around the village of Ontonagon, including several down on homes.  Power was out in the village for nearly 8 hours.

Marine Thunderstorm Wind in ONTONAGON TO UPPER ENTRANCE OF PORTAGE CANAL MI, LAKE SUPERIOR
From 21-JUL-16 06:04:00 to 21-JUL-16 06:09:00 (EST-5)
Location: BEACON HILL
Magnitude: 63.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

The spotter at Freda measured a peak thunderstorm wind gust to 63 mph.

Marine Thunderstorm Wind in POINT ISABELLE TO LOWER ENTRANCE OF PORTAGE CANAL MI, LAKE SUPERIOR
From 21-JUL-16 06:40:00 to 21-JUL-16 06:45:00 (EST-5)
Location: TRAVERSE BAY
Magnitude: 41.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

The peak thunderstorm wind gust at the Grand Traverse Bay GLOS station was 47 mph.