A cold front combined with moderate instability to trigger showers and thunderstorms on the twelfth. Stronger winds aloft due to an upper-level low over New England caused thunderstorms to become well organized. Thunderstorms were able to produce gusty winds over the waters.

Marine Thunderstorm Wind in CHESAPEAKE BAY DRUM PT TO SMITH PT VA, ATLANTIC NORTH
From 12-JUN-11 14:38:00 to 12-JUN-11 14:38:00 (EST-5)
Location: PATUXENT RIVER ASOS
Magnitude: 35.00 MG
Reported by: ASOS

A wind gust of 35 knots was measured near Patuxent River.

Marine Hail in CHESAPEAKE BAY N OF POOLES IS MD, ATLANTIC NORTH
From 12-JUN-11 15:50:00 to 12-JUN-11 15:50:00 (EST-5)
Location: PHILLIPS ARMY AIRFIELD
Magnitude: 0.75 
Reported by: Public

Penny sized hail was reported near Phillips Army Field.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 12-JUN-11 16:40:00 to 12-JUN-11 16:40:00 (EST-5)
Location: QUANTICO
Magnitude: 56.00 EG
Reported by: Trained Spotter

A wind gust was estimated to be around 65 mph based off of thunderstorm wind damage near Indian Head.

Marine Thunderstorm Wind in PATAPSCO RIVER INCLUDING BALTIMORE HARBOR, ATLANTIC NORTH
From 12-JUN-11 16:14:00 to 12-JUN-11 16:34:00 (EST-5)
Location: BALTIMORE CITY
Magnitude: 35.00 MG
Reported by: Mesonet

A wind gust of 35 knots was reported at Tide Point.

Marine Thunderstorm Wind in PATAPSCO RIVER INCLUDING BALTIMORE HARBOR, ATLANTIC NORTH
From 12-JUN-11 16:12:00 to 12-JUN-11 16:24:00 (EST-5)
Location: BALTIMORE CITY
Magnitude: 34.00 MG
Reported by: Buoy

A wind gust of 34 knots was reported at the Baltimore Buoy.

Marine Thunderstorm Wind in PATAPSCO RIVER INCLUDING BALTIMORE HARBOR, ATLANTIC NORTH
From 12-JUN-11 16:19:00 to 12-JUN-11 16:19:00 (EST-5)
Location: BALTIMORE CITY
Magnitude: 35.00 MG
Reported by: Mesonet

A wind gust of 35 knots was measured at the Hampstead Elementary School.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 12-JUN-11 17:07:00 to 12-JUN-11 17:17:00 (EST-5)
Location: TOLLY POINT
Magnitude: 37.00 MG
Reported by: Mesonet

A wind gust of 37 knots was reported at Tolly Point.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 12-JUN-11 17:10:00 to 12-JUN-11 17:10:00 (EST-5)
Location: ANNAPOLIS
Magnitude: 37.00 MG
Reported by: Buoy

A wind gust of 37 knots was reported at the Annapolis Buoy.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 12-JUN-11 18:00:00 to 12-JUN-11 18:00:00 (EST-5)
Location: THOMAS POINT LIGHT
Magnitude: 36.00 MG
Reported by: Buoy

A wind gust of 36 knots was reported at the Thomas Point Lighthouse.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 12-JUN-11 16:40:00 to 12-JUN-11 16:40:00 (EST-5)
Location: QUANTICO
Magnitude: 56.00 EG
Reported by: Trained Spotter

A wind gust was estimated to be around 65 mph based off of thunderstorm wind damage near Indian Head.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 12-JUN-11 16:38:00 to 12-JUN-11 16:38:00 (EST-5)
Location: QUANTICO
Magnitude: 56.00 EG
Reported by: Trained Spotter

A wind gust was estimated to be around 65 mph based off of thunderstorm wind damage near Indian Head.

Marine Thunderstorm Wind in CHESAPEAKE BAY POOLES IS TO SANDY PT MD, ATLANTIC NORTH
From 12-JUN-11 16:22:00 to 12-JUN-11 16:22:00 (EST-5)
Location: MILLER ISLAND
Magnitude: 34.00 MG
Reported by: Mesonet

A wind gust of 34 knots was reported at Miller Island.

Marine Thunderstorm Wind in PATAPSCO RIVER INCLUDING BALTIMORE HARBOR, ATLANTIC NORTH
From 12-JUN-11 16:36:00 to 12-JUN-11 16:36:00 (EST-5)
Location: RIVIERA BEACH
Magnitude: 34.00 EG
Reported by: Buoy

A wind gust in excess of 30 knots was reported at the Francis Scott Key Bridge.

Marine Thunderstorm Wind in CHOPTANK RIVER TO CAMBRIDGE MD AND THE LITTLE CHOPTANK RIVER, ATLANTIC NORTH
From 12-JUN-11 18:06:00 to 12-JUN-11 18:06:00 (EST-5)
Location: CAMBRIDGE
Magnitude: 34.00 MG
Reported by: Buoy

A wind gust of 34 knots was reported near Cambridge.

Marine Thunderstorm Wind in PATUXENT RIVER TO BROOMES ISLAND MD, ATLANTIC NORTH
From 12-JUN-11 14:30:00 to 12-JUN-11 14:30:00 (EST-5)
Location: CHESAPEAKE BIOLOGICAL LABORATORY
Magnitude: 37.00 MG
Reported by: Mesonet

A wind gust of 37 knots was reported at Solomons Island.

Marine Thunderstorm Wind in CHESAPEAKE BAY N BEACH TO DRUM PT MD, ATLANTIC NORTH
From 12-JUN-11 18:15:00 to 12-JUN-11 18:15:00 (EST-5)
Location: CHESAPEAKE BEACH
Magnitude: 61.00 EG
Reported by: Unknown

Wind gusts around 70 mph were estimated near North Point due to thunderstorm wind damage.

Marine Thunderstorm Wind in CHESAPEAKE BAY N BEACH TO DRUM PT MD, ATLANTIC NORTH
From 12-JUN-11 18:15:00 to 12-JUN-11 18:15:00 (EST-5)
Location: CHESAPEAKE BEACH
Magnitude: 56.00 EG
Reported by: Unknown

Wind gusts were estimated to be around 65 mph near North Beach due to thunderstorm wind damage.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 12-JUN-11 17:35:00 to 12-JUN-11 17:35:00 (EST-5)
Location: BABAR POINT
Magnitude: 34.00 MG
Reported by: Mesonet

A wind gust of 34 knots was measured near Babar Point.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 12-JUN-11 17:40:00 to 12-JUN-11 17:55:00 (EST-5)
Location: MONROE CREEK
Magnitude: 50.00 MG
Reported by: Mesonet

Wind gusts up to 50 knots were measured at Monroe Creek.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 12-JUN-11 17:35:00 to 12-JUN-11 17:35:00 (EST-5)
Location: THOMAS POINT LIGHT
Magnitude: 34.00 EG
Reported by: Mesonet

A wind gust in excess of 30 knots was reported at Herring Bay.