Damaging Winds and Lightning Strike in Maryland, July 21, 1998

A small but potent line of severe thunderstorms raced from western Maryland through the Washington DC metropolitan region, producing wind gusts between 60 and 70 mph along the leading edge. The winds knocked down numerous trees and large limbs. Power was knocked out to near 90,000 Potomac Electric Power Co. customers, and many remained without electricity into the following day. Over 100,000 Maryland utility customers lost power at some time during the storm.Damage was first noted in Washington Co, where dozens of trees/large limbs and wires fell. Problems were concentrated across the southern portion of the county near Antietam and Sharpsburg, where some roads were temporarily closed. The storm gained strength as it plowed southeast into Frederick and Montgomery Cos. In Frederick Co, damage included felled scattered trees and power lines in the Middletown/Braddock Heights area. More substantial damage occurred in the south portion of Frederick city, where two roofs partially collapsed at a shopping center near the intersection of state route 85 and Interstate 270. An unfastened trailer was flipped off cinder block supports and fell onto an automobile, pinning the car against a curb. Homes at a nearby neighborhood sustained minor damage, including one whose garage was partially destroyed.Damage in Montgomery Co began along state route 355 near the Gaithersburg/Rockville line, where a portion of an aluminum roof was lifted from a storage facility and blown across the top of an automobile dealership, destroying a satellite dish. Pieces of the roof then fell onto three vehicles below, causing extensive damage to one of them. On the west side of the highway, an unsecured trailer was blown down, and roofing material was peeled off a partially built apartment house. Bricks within the building's elevator shaft were shifted slightly. Four grounded pilots reported witnessing funnel clouds, but an actual tornado sighting could not be confirmed.Several large tree limbs were also blown down in the area. A bit farther east, in Derwood, the tops of several large tulip poplars were snapped; some of the debris caused damage to a resident's patio. More damage occurred in Kensington, when a large hickory tree fell onto a used book business (which was attached to a residence). The tree crushed the roof, scattering thousands of books and destroying two personal computers. In all, there were hundreds of scattered large limbs and/or trees down between Rockville and Silver Spring, several which blocked area thoroughfares. Montgomery Co fire and rescue logged 300 calls between 1700 and 2000EST.The storm began weakening as it approached the eastern suburbs of Washington, DC. Still, damage to trees and power lines continued across much of Prince George's Co, especially between Bowie and Upper Marlboro. A few wires were blown down along the Prince George's/southern Anne Arundel Co line in Wayson's Corner.