An upper-level ridge was centered over the southern Plains while an upper-level low was located over central Canada. A northwest flow between these two systems caused colder air aloft to move overhead. Warm and moist air at the surface combined with the colder air aloft to produce moderate amounts of instability. A pressure trough at the surface caused showers and thunderstorms to develop. Moderate instability caused some thunderstorms to produce gusty winds.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 22:40:00 to 01-AUG-11 22:45:00 (EST-5)
Location: BABAR POINT
Magnitude: 34.00 MG
Reported by: Mesonet

Wind gusts up to 34 knots were reported at Baber Point.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 01-AUG-11 19:35:00 to 01-AUG-11 19:35:00 (EST-5)
Location: POTOMAC BUOY
Magnitude: 34.00 EG
Reported by: Mesonet

A wind gust in excess of 30 knots as reported at Cobb Point.

Marine Thunderstorm Wind in CHESAPEAKE BAY DRUM PT TO SMITH PT VA, ATLANTIC NORTH
From 01-AUG-11 20:40:00 to 01-AUG-11 20:45:00 (EST-5)
Location: POINT LOOKOUT
Magnitude: 35.00 MG
Reported by: Mesonet

Wind gusts up to 35 knots were reported at Point Lookout.

Marine Thunderstorm Wind in PATAPSCO RIVER INCLUDING BALTIMORE HARBOR, ATLANTIC NORTH
From 01-AUG-11 19:44:00 to 01-AUG-11 19:44:00 (EST-5)
Location: BALTIMORE CITY
Magnitude: 34.00 MG
Reported by: Mesonet

A wind gust of 34 knots was measured at Tide Point.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 17:45:00 to 01-AUG-11 17:45:00 (EST-5)
Location: BABAR POINT
Magnitude: 56.00 EG
Reported by: Unknown

Wind gusts around 56 knots were estimated due to thunderstorm wind damage nearby.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 16:47:00 to 01-AUG-11 16:47:00 (EST-5)
Location: QUANTICO
Magnitude: 50.00 EG
Reported by: Unknown

Wind gusts around 50 knots were estimated due to thunderstorm wind damage nearby.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 17:43:00 to 01-AUG-11 17:43:00 (EST-5)
Location: QUANTICO
Magnitude: 34.00 EG
Reported by: ASOS

Wind gusts in excess of 30 knots were reported at Quantico.

Marine Thunderstorm Wind in CHESAPEAKE BAY N BEACH TO DRUM PT MD, ATLANTIC NORTH
From 01-AUG-11 17:50:00 to 01-AUG-11 18:05:00 (EST-5)
Location: CHESAPEAKE BEACH
Magnitude: 49.00 MG
Reported by: Mesonet

Wind gusts up to 49 knots were measured at the Chesapeake Rod N Reel.

Marine Thunderstorm Wind in CHESAPEAKE BAY N BEACH TO DRUM PT MD, ATLANTIC NORTH
From 01-AUG-11 18:45:00 to 01-AUG-11 18:50:00 (EST-5)
Location: CHESAPEAKE BEACH
Magnitude: 63.00 MG
Reported by: Mesonet

Wind gusts between 50 and 63 knots were measured at the Chesapeake Rod N Reel.

Marine Thunderstorm Wind in CHESAPEAKE BAY N OF POOLES IS MD, ATLANTIC NORTH
From 01-AUG-11 20:49:00 to 01-AUG-11 20:54:00 (EST-5)
Location: HAVRE DE GRACE
Magnitude: 42.00 EG
Reported by: Mesonet

Wind gusts up to 42 knots were estimated near the Havre De Grace Middle School.

Marine Thunderstorm Wind in CHESAPEAKE BAY N OF POOLES IS MD, ATLANTIC NORTH
From 01-AUG-11 20:00:00 to 01-AUG-11 20:00:00 (EST-5)
Location: SUSQUEHANNA
Magnitude: 37.00 MG
Reported by: Buoy

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

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 01-AUG-11 18:00:00 to 01-AUG-11 18:00:00 (EST-5)
Location: THOMAS POINT LIGHT
Magnitude: 34.00 EG
Reported by: Buoy

Wind gusts in excess of 30 knots were reported at the Thomas Point Lighthouse.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 01-AUG-11 20:00:00 to 01-AUG-11 20:45:00 (EST-5)
Location: PINEY POINT
Magnitude: 36.00 MG
Reported by: Mesonet

Wind gusts up to 36 knots were reported at Cobb Point.

Marine Thunderstorm Wind in TIDAL POTOMAC COBB IS MD TO SMITH PT VA, ATLANTIC NORTH
From 01-AUG-11 20:24:00 to 01-AUG-11 20:42:00 (EST-5)
Location: PINEY POINT
Magnitude: 34.00 EG
Reported by: Buoy

Wind gusts in excess of 30 knots were reported at Piney Point.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 17:43:00 to 01-AUG-11 17:43:00 (EST-5)
Location: CUCKOLD CREEK
Magnitude: 41.00 MG
Reported by: Mesonet

A wind gust of 41 knots was reported at Cuckold Creek.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 17:40:00 to 01-AUG-11 17:45:00 (EST-5)
Location: BABAR POINT
Magnitude: 34.00 EG
Reported by: Unknown

Wind gusts up to 34 knots were estimated near Baber Point.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 01-AUG-11 18:40:00 to 01-AUG-11 18:40:00 (EST-5)
Location: THOMAS POINT LIGHT
Magnitude: 34.00 EG
Reported by: Mesonet

Wind gusts were estimated to be around 34 knots near Herring Bay.

Marine Thunderstorm Wind in CHESAPEAKE BAY SANDY PT TO N BEACH MD, ATLANTIC NORTH
From 01-AUG-11 17:40:00 to 01-AUG-11 17:55:00 (EST-5)
Location: THOMAS POINT LIGHT
Magnitude: 45.00 EG
Reported by: Mesonet

Wind gusts up to 45 knots were estimated near the Herring Bay.

Marine Thunderstorm Wind in TIDAL POTOMAC INDIAN HD TO COBB IS MD, ATLANTIC NORTH
From 01-AUG-11 19:45:00 to 01-AUG-11 19:50:00 (EST-5)
Location: BABAR POINT
Magnitude: 34.00 EG
Reported by: Mesonet

Wind gusts were estimated to be in excess of 34 knots near Baber Point.