A strong upper trough and associated cold front pushed into the region on the afternoon of the 21st. Good low level moisture and instability combined with an impressive wind field aloft to produce numerous severe thunderstorms during the afternoon and evening hours. All reports of damage were due to strong winds.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:32:00 to 21-AUG-11 14:36:00 (EST-5)
Location: BRISTOL
Magnitude: 50.00 EG
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm downed numerous trees in Bristol, including one on a house.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:40:00 to 21-AUG-11 14:45:00 (EST-5)
Location: RUMNEY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A severe thunderstorm downed a tree across Route 25 taking down wires.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:40:00 to 21-AUG-11 14:42:00 (EST-5)
Location: BRISTOL
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed numerous trees and wires on Rocky Shore Road in Bristol.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:35:00 to 21-AUG-11 14:39:00 (EST-5)
Location: RUMNEY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed trees and wires on Stimson Lake Road in Rumney.

Thunderstorm Wind in CARROLL, NEW HAMPSHIRE
From 21-AUG-11 15:00:00 to 21-AUG-11 15:04:00 (EST-5)
Location: MOULTONBORO
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed a tree on wires and was reported on fire in Moultonborough.

Thunderstorm Wind in CARROLL, NEW HAMPSHIRE
From 21-AUG-11 15:10:00 to 21-AUG-11 15:14:00 (EST-5)
Location: CENTER TUFTONBORO
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed trees and wires in Bridgewater.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 13:54:00 to 21-AUG-11 13:59:00 (EST-5)
Location: CLAREMONT
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed numerous trees in Claremont.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 13:39:00 to 21-AUG-11 13:43:00 (EST-5)
Location: LANGDON
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed numerous trees and wires in Langdon.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 13:43:00 to 21-AUG-11 13:48:00 (EST-5)
Location: ACWORTH
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed numerous trees, including one on a house, in Acworth.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 13:50:00 to 21-AUG-11 13:54:00 (EST-5)
Location: LEMPSTER
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed numerous trees on Lempster Road and Grandview Road in Lempster.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:40:00 to 21-AUG-11 14:45:00 (EST-5)
Location: PLYMOUTH
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Public

A severe thunderstorm downed trees blocking the road between Interstate 93 and Plymouth.

Thunderstorm Wind in CARROLL, NEW HAMPSHIRE
From 21-AUG-11 15:05:00 to 21-AUG-11 15:08:00 (EST-5)
Location: SANDWICH
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A severe thunderstorm downed trees on wires near Israel Road in Sandwich.

Thunderstorm Wind in CARROLL, NEW HAMPSHIRE
From 21-AUG-11 15:30:00 to 21-AUG-11 15:34:00 (EST-5)
Location: CONWAY
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Amateur Radio

A severe thunderstorm downed trees and wires in Center Conway.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 18:35:00 to 21-AUG-11 18:39:00 (EST-5)
Location: PLAINFIELD
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A severe thunderstorm downed trees on Route 12a near Freeman Road in Plainfield.

Thunderstorm Wind in SULLIVAN, NEW HAMPSHIRE
From 21-AUG-11 13:35:00 to 21-AUG-11 13:39:00 (EST-5)
Location: CHARLESTOWN
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

A severe thunderstorm downed numerous trees in Charlestown.

Thunderstorm Wind in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 14:28:00 to 21-AUG-11 14:32:00 (EST-5)
Location: ALEXANDRIA
Magnitude: 50.00 EG
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Trained Spotter

A severe thunderstorm downed trees on wires in Alexandria.

Tornado in GRAFTON, NEW HAMPSHIRE
From 21-AUG-11 19:45:00 to 21-AUG-11 19:50:00 (EST-5)
Location: GRAFTON CENTER
Tornado F-scale: EF1
Crop damage: 0.00K
Reported by: NWS Storm Survey

An EF1 tornado touched down about 8:45 pm in the town of Canaan. The tornado touched down west of Abbott Road, the crossed Abbott Road, Grist Mill Road, and tracked parallel to and just southeast of Ball Park Road.  From there, it crossed Route 4 and Mirror Lake and lifted off the ground just east of the Canaan transfer station.
The tornado was on the ground for about 2.7 miles and had a maximum damage path width of about 350 yards.  The maximum wind gusts were estimated at 95 mph.
The tornado uprooted or snapped several hundred trees along its path.  Several buildings were damaged by falling trees and several outbuildings were damaged by the wind.  In addition, a sailboat and rowboat were moved by the tornado's winds.