On the afternoon of the 11th, thunderstorms with very heavy rainfall, frequent lightning, and damaging winds moved across north central Maryland.  In Harford County, a downburst estimated between 60 and 70 MPH downed trees, damaged homes, and destroyed buildings at a marina about 4 miles east of Edgewood.  The most concentrated area of damage was along the Bush River between Flying Point and Aberdeen Proving Grounds.  Over 30 trees were downed in Flying Point Park.  At the Flying Point Marina, a large pole barn was downed resulting in $100,000 damage.  Small trees were downed and gutters were damaged just west of the park in the Harbor Oaks subdivision.  A person on Flying Point Road observed a 6 foot wide waterspout moving west across the Bush River toward Flying Point during the height of the storm.  Across from Flying Point on the other side of the river, numerous trees were downed in the Bush River Manor subdivision.  Fifteen mobile homes in this community suffered damage from flying debris like metal supports from porches and pieces of skirting.  One metal support rammed into a cinder support block under a trailer and pushed it out of alignment.  The damage path continued south across Boyer Road to the Sod Run Wastewater Treatment Plant where roofing and flashing was ripped off a building.  Airborne gravel and debris knocked out windows on several vehicles.  Next to the plant, a cornfield was flattened, trees were downed, and a fence was blown over.  Nearby on Aberdeen Proving Grounds, about 100 trees were downed and 75 trees were snapped north of Romney Creek.  A wind gauge about a mile south of the downed trees recorded a gust of 40 MPH.  The downburst apparently originated between the water treatment plant and Perryman Road.  Heavy rainfall flooded roads in the Riverside, Edgewood, and Belcamp areas.  Route 7 was closed when 4 feet of water covered the road.  Several motorists were caught in rapidly rising water in Edgewood.  A total of 4.65 inches of rain was recorded in Fallston and 2.7 inches was reported in Bel Air.  A man climbing a ladder in his attic was struck by lightning in Bel Air.  He felt the bolt enter his left hand then he slid down the ladder and called for help.  He was treated for injuries to his palm, arm, shoulder, and chest.  In Howard County, high water closed Route 29 at the intersection of Route 216.  Six additional roads in the Elkridge area were closed by flooding.  Heavy rainfall downed trees onto three roads in the Ellicott City and Lisbon areas.  In Clarksville, a home sustained $100,000 damage from a lightning fire.  A total of 2.54 inches of rain was recorded in Ellicott City.  In Montgomery County, rainfall totals included 4.68 inches in Gaithersburg, 3.22 inches in Bethesda, 2.63 inches in Glenmont, and 2.60 inches in Rockville.  In Gaithersburg, a large store was evacuated after excessive rainfall collected on its roof.  A stream and wetland area flooded onto Clopper Road near I-270.  Trees were downed along Rock Creek after it overflowed.  Motorists were rescued from cars stalled in high water in several spots including Little Falls Parkway, River Road, Connecticut Avenue, and Beach Drive.  Lightning struck a home in Gaithersburg causing minor damage.  In Prince George's County, four people were killed in weather related traffic accidents.

Lightning in HARFORD, MARYLAND
From 11-AUG-01 14:00:00 to 11-AUG-01 14:00:00 (EST)
Location: BEL AIR
Reported by: NEWSPAPER

A man was struck by lightning while climbing a ladder in his attic.

Flash Flood in MONTGOMERY, MARYLAND
From 11-AUG-01 15:15:00 to 11-AUG-01 17:30:00 (EST)
Location: COUNTYWIDE
Reported by: TRAINED SPOTTER

Several roads were flooded after streams overflowed.

Flash Flood in HOWARD, MARYLAND
From 11-AUG-01 15:45:00 to 11-AUG-01 17:30:00 (EST)
Location: COUNTYWIDE
Reported by: NEWSPAPER

Several roads were closed by flooding and heavy rainfall downed trees.

Lightning in HOWARD, MARYLAND
From 11-AUG-01 15:38:00 to 11-AUG-01 15:38:00 (EST)
Location: CLARKSVILLE
Property damage: 100K
Reported by: NEWSPAPER

A home was damaged by lightning.

Thunderstorm Wind in HARFORD, MARYLAND
From 11-AUG-01 13:45:00 to 11-AUG-01 13:45:00 (EST)
Location: EDGEWOOD
Property damage: 120K
Reported by: NWS STORM SURVEY

A downburst estimated between 60 and 70 MPH downed several trees and damaged the Flying Point Marina.

Waterspout in HARFORD, MARYLAND
From 11-AUG-01 13:45:00 to 11-AUG-01 13:45:00 (EST)
Location: EDGEWOOD
Reported by: GENERAL PUBLIC

A microburst spawned a small waterspout on the Bush River.

Flash Flood in HARFORD, MARYLAND
From 11-AUG-01 13:45:00 to 11-AUG-01 15:00:00 (EST)
Location: COUNTYWIDE
Reported by: NEWSPAPER

Several roads including Route 7 were flooded.