A southerly flow around high pressure off the east coast produced hot and humid conditions. The hot and humid conditions combined with colder air aloft associated with an upper-level trough to produce moderate amounts of instability. Some thunderstorms that developed produced damaging wind gusts and large hail.

Thunderstorm Wind in CULPEPER, VIRGINIA
From 18-AUG-11 21:56:00 to 18-AUG-11 21:56:00 (EST-5)
Location: MONUMENT MILLS
Magnitude: 52.00 EG
Property damage: 1.00K
Reported by: Public

Large tree limbs were broken in thunderstorm winds.

Thunderstorm Wind in FAIRFAX, VIRGINIA
From 18-AUG-11 17:00:00 to 18-AUG-11 17:00:00 (EST-5)
Location: SUNSET HILLS
Magnitude: 50.00 EG
Property damage: 0.50K
Reported by: Trained Spotter

Tree limbs that were two inches in diameter were snapped off softwood trees.

Hail in LOUDOUN, VIRGINIA
From 18-AUG-11 19:00:00 to 18-AUG-11 19:00:00 (EST-5)
Location: PLEASANT VLY
Magnitude: 1.75 
Reported by: Public

Golf ball sized hail was reported near the Dulles Airport.

Hail in LOUDOUN, VIRGINIA
From 18-AUG-11 20:20:00 to 18-AUG-11 20:20:00 (EST-5)
Location: WAXPOOL
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter sized hail was reported near Ashburn.

Hail in CULPEPER, VIRGINIA
From 18-AUG-11 21:54:00 to 18-AUG-11 21:54:00 (EST-5)
Location: MONUMENT MILLS
Magnitude: 1.00 
Reported by: Public

Quarter sized hail was reported near Viewtown.

Thunderstorm Wind in RAPPAHANNOCK, VIRGINIA
From 18-AUG-11 21:32:00 to 18-AUG-11 21:32:00 (EST-5)
Location: ROCK MILLS
Magnitude: 50.00 EG
Property damage: 3.00K
Reported by: State Official

Trees were down on Rock Mills Road.

Thunderstorm Wind in RAPPAHANNOCK, VIRGINIA
From 18-AUG-11 21:34:00 to 18-AUG-11 21:34:00 (EST-5)
Location: BEU VENUE
Magnitude: 50.00 EG
Property damage: 3.00K
Reported by: State Official

Trees were down on Richmond Road.

Hail in WARREN, VIRGINIA
From 18-AUG-11 18:33:00 to 18-AUG-11 18:33:00 (EST-5)
Location: BROWNTOWN
Magnitude: 1.00 
Reported by: Public

Quarter sized hail was reported near Browntown.

Hail in FAIRFAX, VIRGINIA
From 18-AUG-11 18:30:00 to 18-AUG-11 18:30:00 (EST-5)
Location: BULL RUN
Magnitude: 1.75 
Reported by: Trained Spotter

Golf ball sized hail was reported.

Hail in LOUDOUN, VIRGINIA
From 18-AUG-11 17:07:00 to 18-AUG-11 17:07:00 (EST-5)
Location: STERLING
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter sized hail was reported in Sterling.

Hail in LOUDOUN, VIRGINIA
From 18-AUG-11 17:08:00 to 18-AUG-11 17:08:00 (EST-5)
Location: BROAD RUN FARMS
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter sized hail was reported near Sterling Park.

Hail in PRINCE WILLIAM, VIRGINIA
From 18-AUG-11 18:26:00 to 18-AUG-11 18:26:00 (EST-5)
Location: CATHARPIN
Magnitude: 1.50 
Reported by: Public

Hail up to ping pong balls in size was reported near Catharpin.

Hail in PRINCE WILLIAM, VIRGINIA
From 18-AUG-11 18:30:00 to 18-AUG-11 18:30:00 (EST-5)
Location: CATHARPIN
Magnitude: 1.75 
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

Hail up to golf balls in size was reported.

Thunderstorm Wind in SHENANDOAH, VIRGINIA
From 18-AUG-11 19:46:00 to 18-AUG-11 19:46:00 (EST-5)
Location: WOODSTOCK
Magnitude: 50.00 EG
Property damage: 1.00K
Reported by: State Official

A tree was down near the intersection of Fravel Road and Spring Hollow Road.

Hail in LOUDOUN, VIRGINIA
From 18-AUG-11 16:55:00 to 18-AUG-11 16:55:00 (EST-5)
Location: STERLING
Magnitude: 1.00 
Reported by: NWS Employee

Quarter sized hail was reported near Herndon.

Hail in PRINCE WILLIAM, VIRGINIA
From 18-AUG-11 17:15:00 to 18-AUG-11 17:15:00 (EST-5)
Location: CATHARPIN
Magnitude: 1.00 
Reported by: Public

Quarter sized hail was reported near Catharpin.

Hail in FAIRFAX (C), VIRGINIA
From 18-AUG-11 16:24:00 to 18-AUG-11 16:24:00 (EST-5)
Location: FAIRFAX
Magnitude: 1.00 
Reported by: Trained Spotter

Quarter sized hail was reported in Fairfax.