National Weather Service: Straight-line winds knocked down trees, wires in Columbia

Jun. 11—Residents reported seeing a tornado in Columbia during severe storms Wednesday evening, which forced the cancellation of a concert at Merriweather Post Pavilion and put flood-prone Historic Ellicott City on alert, said Howard County executive Calvin Ball during a news conference Thursday in Tiber Park.

However, the National Weather Service concluded that there was no tornado but rather straight-line winds from a downburst of a severe thunderstorm.

Post-storm surveys conducted Thursday by the NWS office in the Columbia area of Howard County showed straight-line winds, which can cause tornado-like damages, lasted up to 15 minutes and had wind speeds of 75 mph.

These straight-line winds had knocked down hundreds of trees and wires from Atholton Park to the Oakland Mills neighborhood, both in Columbia.

It started in the vicinity of Old Columbia Road, where a hardwood tree was uprooted, and moved over Patuxent Freeway before reaching the park area. There were considerable debris, some trees had been uprooted, snapped or branches broken off in addition to fallen chimneys, according to NWS, but there were no structural damages observed to homes.

"We know of at least one tree that has fallen on to a house and one that came down onto an apartment building," in the area of Cradlerock Way, near Lake Elkhorn Park, said Ball, and was where residents reported a possible twister.

The Stevens Forest Road and Cradlerock Way area sustained the brunt force of the thunderstorm and was where hundreds of trees had been destroyed. Fallen trees and severe wind gusts had also damaged residential structures, according to NWS.

A fence was also blown over near Stevens Forest Elementary School and Camelback Lane, and a large tree limb was seen pierced through the roof of a residence in the area too, according to NWS.

The Kendall Ridge area also likely experienced straight-line wind damage. Some trees had been uprooted and numerous 3 to 6 inch tree branches had been snapped in the densely forested area of the bike trail. There were no damages to nearby residences or other structures, according to NWS.

The weather service is also sending surveyors to St. Mary's County following reports of possible tornado damage there, said meteorologist Jeremy Geiger.

Heavy rain fell throughout Central Maryland Wednesday evening, downing trees, flooding roads and postponing a Baltimore Orioles game. In Howard County — which Geiger called a "sweet spot" for the storms — about 30 roads were impacted by flooding or downed trees, Ball said, and as many as 3,000 Baltimore Gas and Electric customers lost power. The number was about 300 by morning, he said.

The storm halted and then canceled a Halsey concert at Merriweather, which drew about 13,000 fans to Columbia, said Chief Louis Winston of Howard County Fire and Rescue. Video captured floodwaters pouring into the outdoor covered pavilion during the storm, where concertgoers had gathered as rain poured.

"Our crews were able to quickly get over there and assess that area and determined there was no imminent danger to the patrons that were under the pavilion at that time," Winston said during Thursday's news conference.

The venue put the show on hold shortly after it began, Winston said, after reports of lightning in the area. Fans sitting on the lawn were asked to move under the pavilion, he said. By 9:45 p.m., Merriweather officials decided to cancel the show, Winston said.

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Additionally, Audrey Fix Schaefer, a spokesperson for the Pavilion, said in an email that the decision to cancel the show was made as the storm "struck more intensely and lasted longer than anticipated."

After the bouts of fast-falling rain, floodwaters reached curb-level in Historic Ellicott City, still scarred by deadly flash floods in 2016 and 2018, but there was minimal property damage along Main Street and no injuries, Ball said during Thursday's news conference.

"Though yesterday's storm was nerve-wracking for many, the systems that we put in place together worked as intended, especially here in Ellicott City," he said.

Once a flash flood watch was issued, the city unlocked private access point gates, installed in 2020, which provide a quick route out of the floodplain, and posted information about the watch on city message boards, Ball said.

Starting around 6 p.m., short but high-intensity storms moved through the county. Historic Ellicott City saw 2.3 inches of rain in about two hours, with 1.25 inches falling between 8:45 p.m. and 9 p.m. alone, Ball said. It came close to the precipitation rate from the 2018 storm that flooded Main Street: 1.44 inches in 15 minutes, he said. After the weather service issued a flash flood warning around 9 p.m., the city activated its outdoor sirens, which were installed in 2019, Ball said. Police officers also closed Main Street, and reopened it once the storms had passed.

In the next three business days, county workers will inspect stream channels and remove debris to prevent build-up, Ball said. The county is still working to finish construction on the H7 Pond and Quaker Mill Pond, which would store rainwater to prevent it from reaching Historic Ellicott City, he said.. The county also recently received a $75 million-loan through the Environmental Protection Agency to improve flood infrastructure, which will largely go toward extending the North Tunnel to draw more than 26,000 gallons of water away from Historic Ellicott City, Ball said.

"We implemented these and other initiatives as part of our Ellicott City Safe and Sound Plan because we knew that when another storm came, we needed to be better prepared," Ball said.