Tornadoes and Flash Flood in Maryland, June 16, 1998

The approach of a cold front combined with impressive jet stream energy at upper-levels of the atmosphere acted on unstable air near the surface to produce a major severe weather episode across northern Maryland for the second time in three weeks. The combustible situation produced a mesoscale low pressure system which focused the most substantial severe which focused the most substantial severe weather in north-central Maryland. The episode featured five tornadoes, nearly a dozen instances of wind damage, and several large hail occurrences.The most concentrated damage was in and around Hagerstown. Three separate tornadoes dropped from the same parent thunderstorm within moments of each other. The first two caused considerable property damage between the town of Halfway and Hagerstown. The third produced a track of mainly tree and underbrush damage from just south of the Washington County Regional Airport to the Maryland/Pennsylvania state line. The first twister, which developed three miles south of Halfway, toppled and uprooted dozens of trees and blew down wires in the Tammany Manor neighborhood, as well as at the Hickory Elementary School. The tornado saved its worst for the Valley Mall, where a portion of the roof was torn off and damage was noted at an anchor store's loading dock. Another adjacent store had an electrical fire.More commercial damage occurred a few blocks north, along Wesel Boulevard, where the roofs of several vacant buildings were torn off. Canopy tents at the Wal-Mart department store were flattened; the store's garden center had its greenhouse destroyed; many pieces of equipment, and plants and flowers, were also damaged. An awning at a local automobile dealership was ripped off. This tornado dissipated just southeast of the Washington Co. Detention Center - but not before knocking down trees along Interstate 81, temporarily closing one of the two travel lanes.Shortly before the first tornado lifted, a second touched down in the Greenbury Hills subdivision of Halfway, uprooting trees and ripping siding from a few homes. This twister, on the ground for five miles, caused much of its damage over the western portion of Hagerstown before dissipating. At the Potomac Center, 44 trees were uprooted, and another 40 were damaged. Dozens more were snapped and uprooted at the nearby Carroll Heights/Hyde Park subdivision; trees were also uprooted and snapped at the Rest Haven Cemetery, with at least four fallen trees knocking over headstones. Hundreds more trees were damaged at both the Hagerstown Business College and the nearby Fountain Head Country Club, whose golf course was closed for two days to clean up the debris.While eastern Washington Co was being pummelled, another cell was producing wind damage from southwestern through central Frederick Co. Several trees were snapped and uprooted, and some homes sustained damage to shingles, siding, and porch supports, in Middletown. More damage was noted between Jefferson and Buckeystown - another microburst - witnessed by residents as a rolling black cloud. Damage included numerous trees snapped and uprooted, a destroyed cinder block outbuilding, and a damaged garage door. Farther to the northeast, more trees were snapped, including one which fell onto a house near Libertytown. A small tornado touched down just northeast of Frederick city, taking down about a half-dozen trees near the intersection of Gas House and Linganore Roads. Intense lightning caused problems as well. The radio transmission tower which serves the Frederick Co emergency operations center was knocked out, with damage reported to radio and telecommunications equipment. Several homes were struck in the area, as was a fire department vehicle.Severe weather propagated eastward into Carroll and Baltimore Cos. Damaging winds snapped and uprooted many trees in Westminster, including one which fell onto a home. Two trees crashed through residents' roofs along state route 31 near Westminster. Large hail the size of tennis balls caused scattered damage to homes and vehicles in Finksburg. The heavy rains associated with the stronger cells caused flash flooding across portions of the Big Pipe Creek watershed in northern Carroll Co; several roads were temporarily closed near Taneytown where the Bear Branch overflowed its banks. One road was washed out. Lightning struck at least one home and barn, causing small fires and minor damage.Just west of the Baltimore/Carroll line (1 mile southwest of Fowblesburg), a small tornado knocked down several trees, some which fell onto a house, a camper, and a shed. Sheet metal was stripped from the shed; the trees were severely twisted, according to the resident. More trees or large limbs fell in Reisterstown (Baltimore Co) and in northern Howard Co.As events were winding down across northern Maryland, another severe storm moved out of east-central Virginia and into lower southern Maryland, causing damage in counties that had been struck the previous evening. Trees and large limbs fell across portions of northern and eastern Charles Co, but the storm apparently saved its worst for St Mary's Co, where three barns were destroyed and numerous trees were snapped or uprooted along the state route(s) 239/520 corridor near Milestown. In Calvert Co, more trees/large limbs fell, and a portion of roof and some siding were stripped from one home.Thousands of Maryland residents lost power yet again due to the storms; a total of at least 25,000 customers in the Baltimore Gas and Electric and Allegheny Power service areas had no electricity during the height of the storm.