A return flow around high pressure pumped in plenty of warm and moist air over the region. Colder air aloft associated with an upper-level trough combined with the warm and moist air at the surface to develop moderate amounts of instability. A surface trough acted as the lifting mechanism for showers and thunderstorms to develop during the afternoon and evening hours. Thunderstorms were able to produce damaging wind gusts.

Thunderstorm Wind in ANNE ARUNDEL, MARYLAND
From 17-JUN-11 18:15:00 to 17-JUN-11 18:15:00 (EST-5)
Location: FRIENDSHIP
Magnitude: 56.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Several trees were down along Route 261.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:15:00 to 17-JUN-11 18:15:00 (EST-5)
Location: NORTH BEACH
Magnitude: 56.00 EG
Property damage: 1.00K
Reported by: Trained Spotter

A large tree was down near 3rd Street and Frederick Avenue.

Thunderstorm Wind in ANNE ARUNDEL, MARYLAND
From 17-JUN-11 18:16:00 to 17-JUN-11 18:16:00 (EST-5)
Location: FAIR HAVEN
Magnitude: 50.00 MG
Reported by: Mesonet

A wind gust of 58 mph was measured near North Beach.

Hail in FREDERICK, MARYLAND
From 17-JUN-11 15:30:00 to 17-JUN-11 15:30:00 (EST-5)
Location: FREDERICK
Magnitude: 1.00 
Reported by: NWS Employee

Quarter sized hail was measured.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:03:00 to 17-JUN-11 18:03:00 (EST-5)
Location: DUNKIRK
Magnitude: 61.00 EG
Property damage: 10.00K
Reported by: Fire Department/Rescue

Multiple trees were down in the Dunkirk area.

Thunderstorm Wind in ANNE ARUNDEL, MARYLAND
From 17-JUN-11 18:05:00 to 17-JUN-11 18:05:00 (EST-5)
Location: LYONS CREEK
Magnitude: 56.00 EG
Property damage: 2.00K
Reported by: Broadcast Media

Trees were down in the vicinity of MD-4 and MD-260.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:05:00 to 17-JUN-11 18:05:00 (EST-5)
Location: CHANEY
Magnitude: 56.00 EG
Property damage: 2.00K
Reported by: Trained Spotter

Trees were down across MD-4 at Lyons Creek Road.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:06:00 to 17-JUN-11 18:06:00 (EST-5)
Location: DUNKIRK
Magnitude: 52.00 EG
Property damage: 10.00K
Reported by: Fire Department/Rescue

Trees were knocked onto a mobile home near Route 4 and Brickhouse Road.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:06:00 to 17-JUN-11 18:06:00 (EST-5)
Location: CHANEYVILLE
Magnitude: 61.00 EG
Property damage: 2.00K
Reported by: NWS Employee

Trees were uprooted and snapped near Chaneyville.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:07:00 to 17-JUN-11 18:07:00 (EST-5)
Location: OWINGS
Magnitude: 61.00 EG
Property damage: 10.00K
Reported by: Trained Spotter

Several trees were down along Route 260 from Chesapeake Beach to Dunkirk.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:12:00 to 17-JUN-11 18:12:00 (EST-5)
Location: CHESAPEAKE BEACH
Magnitude: 56.00 EG
Property damage: 5.00K
Reported by: Fire Department/Rescue

Multiple trees and power lines were down in the Chesapeake Beach area.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:15:00 to 17-JUN-11 18:15:00 (EST-5)
Location: NORTH BEACH
Magnitude: 61.00 EG
Property damage: 5.00K
Reported by: Trained Spotter

Trees were down along 5th Street.

Thunderstorm Wind in CALVERT, MARYLAND
From 17-JUN-11 18:06:00 to 17-JUN-11 18:06:00 (EST-5)
Location: DUNKIRK
Magnitude: 52.00 EG
Property damage: 2.00K
Reported by: Fire Department/Rescue

Trees and power lines were down near Route 4 and Brickhouse Road.