An upper disturbance moving through a warm and unstable air mass produced severe thunderstorms over northern Lake Michigan on the 18th.

Marine Hail in SEUL CHOIX POINT TO POINT DETOUR MI, LAKE MICHIGAN
From 18-JUN-12 13:29:00 to 18-JUN-12 13:31:00 (EST-5)
Location: MANISTIQUE LIGHT
Magnitude: 1.50 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Large hail was reported at the Seul Choix Point Lighthouse.

Marine Thunderstorm Wind in GREEN BAY N FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 12:35:00 to 18-JUN-12 12:37:00 (EST-5)
Location: POINT DETOUR
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts measured by the Garden spotter.

Marine Thunderstorm Wind in SEUL CHOIX POINT TO POINT DETOUR MI, LAKE MICHIGAN
From 18-JUN-12 12:35:00 to 18-JUN-12 12:37:00 (EST-5)
Location: CHARBONEAU POINT
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

Wind gusts measured by the Garden spotter.

Marine Thunderstorm Wind in GREEN BAY N FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 05:50:00 to 18-JUN-12 06:00:00 (EST-5)
Location: POINT DETOUR
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gust measured at the Fairport GLOS site.

Marine Thunderstorm Wind in SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5NM OFFSHORE TO MID LAKE, LAKE MICHIGAN
From 18-JUN-12 05:50:00 to 18-JUN-12 06:00:00 (EST-5)
Location: POINT DETOUR
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gust measured at the Fairport GLOS site.

Marine Thunderstorm Wind in SEUL CHOIX POINT TO ROCK ISLAND PASSAGE 5NM OFFSHORE TO MID LAKE, LAKE MICHIGAN
From 18-JUN-12 06:00:00 to 18-JUN-12 06:05:00 (EST-5)
Location: SAINT MARTIN ISLAND LIGHT
Magnitude: 35.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Buoy

Wind gust was measured by the northern Lake Michigan buoy 45002.

Marine Hail in GREEN BAY N FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 14:35:00 to 18-JUN-12 14:38:00 (EST-5)
Location: GLADSTONE
Magnitude: 2.00 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Two inch diameter hail was measured by the observer in Gladstone.

Marine Thunderstorm Wind in GREEN BAY N FROM CEDAR RIVER MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 16:06:00 to 18-JUN-12 16:20:00 (EST-5)
Location: POINT DETOUR
Magnitude: 45.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Maximum wind gust measured by the Fairport GLOS.

Marine Thunderstorm Wind in SEUL CHOIX POINT TO POINT DETOUR MI, LAKE MICHIGAN
From 18-JUN-12 16:06:00 to 18-JUN-12 16:20:00 (EST-5)
Location: POINT DETOUR
Magnitude: 46.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Maximum wind gust measured by the Fairport GLOS.

Marine Thunderstorm Wind in 5NM E OF FAIRPORT MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 16:06:00 to 18-JUN-12 16:20:00 (EST-5)
Location: POINT DETOUR
Magnitude: 46.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Maximum wind gust measured by the Fairport GLOS.

Marine Thunderstorm Wind in 5NM E OF FAIRPORT MI TO ROCK ISLAND PASSAGE, LAKE MICHIGAN
From 18-JUN-12 05:50:00 to 18-JUN-12 06:00:00 (EST-5)
Location: POINT DETOUR
Magnitude: 39.00 MG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Wind gust measured at the Fairport GLOS site.