Slow-moving storms trained south-southeastward over the Roanoke Valley on Thursday evening, dumping 3 to 5 inches of rain in under two hours on some parts of Roanoke’s western side, causing flash flooding of streets and low-lying areas.
By 8:30 p.m., at least a dozen swift-water rescues had been conducted, according to a report to the National Weather Service citing Roanoke city emergency management. The first floor of an extended stay apartment building was evacuated near the Roanoke-Blacksburg Regional Airport, according to another emergency manager storm report.
The heaviest rain was focused on the city’s northwest corner on either side of Interstate 581, generally along Peters Creek Road, which was flooded with up to two feet of water around many vehicles. Water filled Shaffer’s Crossing and the Ring Road around the Valley View Mall, according to reports received by the weather service.
The official gauge at the Roanoke airport recorded very nearly 4 inches of rain — 3.99 inches — between 7 and 9 p.m., including 3.38 inches in a single hour from 7 to 8.
The localized extraordinary rainfall and flooding in the Peters Creek Road area of Roanoke bears a strong resemblance to a similar cloudburst on July 10, 2013, that dumped 3.88 inches of rain at the airport gauge. Shortly after that event, the National Weather Service said the 3.35 inches of rain in an hour was between a once-in-200-year and once-in-500-year occurrence. This episode 12 years later has slightly exceeded that.
Rain spread across the Roanoke Valley with lesser totals and southward along the Blue Ridge, with street flooding also reported in the Callaway area of Franklin County later Thursday evening.
Heavier rainfall was very streaky in Southwest and Southside Virginia on Thursday, with many locations receiving little or none while others in narrow strips were inundated.
Thursday night’s rainfall was connected to the circulation around Hurricane Erin, passing east of the U.S., but not directly a part of the storm. Moisture circulated inland banked against the mountains and subtle atmospheric boundaries, lifted and condensed aloft by daytime heating, leading to the development of showers and thunderstorms in narrow strips that slid south-southeastward over the same locations in repetition while missing many others.
Coverage of rain showers and thunderstorms is expected to dwindle into the weekend, but not entirely disappear. A strong cold front next week is expected to bring much cooler and drier weather to our region, with some 40s to lower 50s low temperatures possible.
Journalist Kevin Myatt has been writing about weather for 20 years. His weekly column, appearing on Wednesdays, is sponsored by Oakey’s, a family-run, locally-owned funeral home with locations throughout the Roanoke Valley. Sign up for his weekly newsletter: