Severe weather season is upon us — what the threats are in our area and when they peak

PITTSBURGH — Severe weather season is upon us in western Pennsylvania. Pittsburgh is prone to flash flooding, and the city can even see hail and tornadoes. We also know that lightning is a threat in any thunderstorm.

In June of 2018, a SUV floated away in a parking lot after torrential downpours, and people had to rescued from the Trolley Stop Inn Restaurant. We’re still reminded of the deadly flooding on Washington Boulevard in 2011, where fast-rising waters took four lives. Floodgates are now installed.

There are signs that this spring will be wetter than average due to the La Niña climate pattern that has dominated our winter weather. It can have an influence on spring weather, too. During a La Niña, the jet stream pushes farther north, which can lead to more showers and storms in our region as we tap into warm, humid air from the Gulf of Mexico. This pattern also favors more severe weather across the southern U.S. Our average spring rainfall in Pittsburgh is about 10 inches.

The threat of flash flooding in Pittsburgh is highest in June and July, although it can happen any time of the year. In fact, Allegheny County has more flash flood reports than any other county in western Pennsylvania.

Western Pennsylvania has also had tornado outbreaks. On June 2, 1998, more than a half-dozen tornadoes struck the area, including a high-end EF1 that hit Carnegie and Mount Washington. That storm caused 50 injuries and $13 million in damage.

Tornado occurrence begins to climb in March and peaks in June. Fortunately, about four out of five tornadoes here are of the weaker variety, EF0 to EF1, with winds less than 110 mph.

Microbursts are also common in our area.

On May 31, 2002, a microburst slammed Kennywood Park, killing a woman and injuring many others.

Severe wind events, ones classified by having winds of 58 mph or greater, have been known to occur throughout the year, but are more frequent during the summer months.

With the threat of severe weather peaking in the next few months, it’s important to have our Severe Weather Team 11 app. It’s free to download on your smartphone and it has radar, video forecasts, and can give you alerts when you’re at home or on the go.