By Stephen Smoot
Last week, storms raged across West Virginia, prompting a statewide disaster declaration for all 55 counties by Governor Patrick Morrissey.
Two tornadoes touched down in Pendleton County and one near High View in Hampshire County. While Hardy received two warnings that storms had conditions right for tornado formation, none touched down in Hardy County.
Hardy County also escaped the furious rainstorms that brought destruction and loss of life to Lewis and Upshur counties.
Some of these, particularly those that drove through North Central West Virginia and through the Potomac Highlands before entering Virginia, were of the “supercell” variety.
Supercell storms pose more danger than even the destructive “derecho” types of storms. Those are multiple “ordinary cell” storms that move in tandem as a line extending for hundreds of miles. Normally derecho damage comes from “straight line” winds rather than tornadoes.
According to the National Weather Service, supercells “are highly organized storms characterized by updrafts that can attain speeds of over 100 mph and are able to produce giant hail with strong, or even violent, tornadoes.” Downdrafts, or winds forcefully pushing downward from the storm “can produce downbursts/outflow winds in excess of 100 mph.”
Atmospheric instability and, in this case a hard cold front, helped to form “ideal” conditions for supercells. Wind dynamics can cause the entire storm to rotate. Precipitation can fall so heavily that it obscures tornadoes hidden within. Heavy precipitation will also bring the likelihood of flash flooding or worse.
Several inches of rain falling in a short duration created deadly and destructive flooding in Upshur and Lewis counties. Water running through town streets appeared almost as creeks or rivers. Flooding also blocked both Corridor H at Weston and Interstate 79 nearby. Weston received just under five inches of rain while Buckhannon got 5.3. Some communities directly south of the Corridor H highway connecting those cities saw almost 6.5 inches.
Flooding took place along some smaller streams in the area, but the United States Geological Survey gauge near Moorefield showed that the river level rose to just short of eight feet, a few inches below the level set on July 18. Wind gusts likely exceeded 60 mph in the area at times. Rainfall for Moorefield topped out at just under one half an inch that evening.
The NWS did include a prediction of supercell storms in its special alert for the Mid Atlantic region on July 21.
Hardy County saw two separate tornado warnings. Storm rotations that indicated the likelihood of a tornado sparked warnings in two areas, from near Purgitsville and extending to Wardensville and also from an area south of Petersburg reaching into southern Hardy County.
Pendleton County endured two actual tornado touchdowns, confirmed by the National Weather Service. One landed, according to Rick Gillespie from the Pendleton County Office of Emergency Management, “east of Franklin, on a line to the Fort Seybert area” and crossed into Rockingham County. A motorist searching for a jogger almost was struck by falling trees.
The second landed “southeast of Seneca Rocks with reported damages all on a single property.” Hampshire County’s tornado ranged into Virginia without causing much trouble.
