Central Lawrenceville buzzed with the sounds of chainsaws Monday, after strong winds and rain from a weekend downburst uprooted several trees in the Allegheny Cemetery. Crews spent Monday afternoon cutting off branches from a particularly large tree hovering over a grassy patch near the cemetery’s gates off Butler Street.
Several bulidings were also damaged during the storm.
James Coen owns a brick building at the corner of 48th and Butler streets from which nearly two full stories toppled off during the brief storm. Two floors and half of a third, lined with jagged missing masonry, can be seen from the street. Coen, who was at his Strip District store Yinzers at the time, said winds knocked a fourth story completely off and threw debris as far as 300 feet from the building.
“For that to blow that far, and no one getting injured, it was a miracle,” he said.
Coen bought the building with the intention of turning it into a mixed-use property, with a business on the first floor and residential space above it.
A downburst occurs during a thunderstorm, when strong winds push rain up into the atmosphere. Eventually the mass of rain and ice becomes so heavy that it descends, striking the earth.
“I call it a splat,” said Matthew Kramer, a meteorologist who specializes in severe weather. “It just hits the ground and splats out, and spreads out radially from where it hit the ground.”
This causes strong winds, which can exceed 100 miles per hour. Kramer said this weekend’s winds were potentially as high as 60 or 70 miles an hour.
Downbursts are common in July and August, and are extremely hard to predict because they happen so quickly.
“The best we can do ... is to anticipate the environment that they’re forming in,” said Kramer. “The key takeaway here is that when there is a severe thunderstorm warning, you need to be prepared for this kind of impact.”
Several media reports refer to the Saturday event as a microburst, but Kramer said that hasn't been confimed. A microburst is usually confined to a few, square kilometers, but Kramer said the weather service hasn't surveyed the area to determine the size of the downburst.