A surface trough remained over the waters while a series of upper-level disturbances passed through in a zonal flow aloft. Hot and humid conditions led to moderate amounts of instability. Some thunderstorms that developed were able to produce gusty winds due to the instability.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 20-JUL-10 18:40:00 to 20-JUL-10 18:40:00 (EST-5)
Location: QUANTICO
Magnitude: 36.00 MG
Reported by: Mesonet

A wind gust of 36 knots was reported at Mason Neck.

Marine Thunderstorm Wind in TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND, ATLANTIC NORTH
From 20-JUL-10 20:12:00 to 20-JUL-10 20:12:00 (EST-5)
Location: BISHOPS HEAD
Magnitude: 34.00 EG
Reported by: Mesonet

A wind gust in excess of 30 knots was reported at Bishops Head.

Marine Thunderstorm Wind in TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND, ATLANTIC NORTH
From 20-JUL-10 20:25:00 to 20-JUL-10 20:25:00 (EST-5)
Location: RACCOON POINT
Magnitude: 36.00 MG
Reported by: Mesonet

A wind gust of 36 knots was measured at Raccoon Point.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 18:40:00 to 20-JUL-10 18:40:00 (EST-5)
Location: POTOMAC BUOY
Magnitude: 36.00 MG
Reported by: Buoy

A wind gust of 36 knots was measured at Potomac Buoy.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 20-JUL-10 18:43:00 to 20-JUL-10 18:43:00 (EST-5)
Location: POTOMAC LIGHT
Magnitude: 34.00 EG
Reported by: Mesonet

A wind gust in excess of 30 knots was reported at the Potomac Lighthouse.

Marine Thunderstorm Wind in CHESAPEAKE BAY DRUM PT TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 19:35:00 to 20-JUL-10 19:35:00 (EST-5)
Location: POINT LOOKOUT
Magnitude: 39.00 MG
Reported by: Mesonet

Wind gusts between 34 and 39 knots were reported at Point Lookout.

Marine Thunderstorm Wind in CHESAPEAKE BAY N OF POOLES IS MD, ATLANTIC NORTH
From 20-JUL-10 11:59:00 to 20-JUL-10 12:01:00 (EST-5)
Location: HAVRE DE GRACE
Magnitude: 49.00 MG
Reported by: Mesonet

Wind gusts between 34 and 49 knots were measured about six miles east-southeast of Havre De Grace.

Marine Thunderstorm Wind in CHESAPEAKE BAY N OF POOLES IS MD, ATLANTIC NORTH
From 20-JUL-10 12:00:00 to 20-JUL-10 12:00:00 (EST-5)
Location: SUSQUEHANNA
Magnitude: 36.00 MG
Reported by: Buoy

A wind gust of 36 knots was reported at Susquehanna Buoy.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 19:18:00 to 20-JUL-10 19:18:00 (EST-5)
Location: PINEY POINT
Magnitude: 34.00 EG
Reported by: Buoy

A wind gust in excess of 30 knots was measured at Piney Point.

Marine Thunderstorm Wind in CHESAPEAKE BAY DRUM PT TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 19:57:00 to 20-JUL-10 20:22:00 (EST-5)
Location: SMITH ISLAND
Magnitude: 39.00 MG
Reported by: Mesonet

Wind gusts up to 39 knots were reported at Smith Island.

Marine Thunderstorm Wind in TANGIER SOUND AND THE INLAND WATERS SURROUNDING BLOODSWORTH ISLAND, ATLANTIC NORTH
From 20-JUL-10 20:12:00 to 20-JUL-10 20:23:00 (EST-5)
Location: BISHOPS HEAD
Magnitude: 34.00 MG
Reported by: Mesonet

Wind gusts up to 34 knots were reported at Bishops Head.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 19:18:00 to 20-JUL-10 19:18:00 (EST-5)
Location: LEWISETTA
Magnitude: 34.00 EG
Reported by: Buoy

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

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 20-JUL-10 19:18:00 to 20-JUL-10 19:18:00 (EST-5)
Location: LEWISETTA
Magnitude: 34.00 EG
Reported by: Buoy

Wind gusts in excess of 30 knots were estimated near Lewisetta.