Western Pennsylvania may be far outside of America’s Tornado Alley, but so far this season, the region has experienced an unusually high string of twisters.

On Saturday, May 11, alone, three tornadoes formed over Western Pennsylvania, striking Washington and Fayette counties.

The streak continued six days later, when four more tornadoes touched down on Westmoreland and Washington counties and the city of Pittsburgh on Friday. A fifth tornado was reported the following day over Carroll County, Ohio.

These make up a portion of the 19 tornadoes which have struck in the National Weather Service’s Pittsburgh region so far this year, which includes parts of Western Pennsylvania, eastern Ohio, and northern West Virginia.

One of those tornadoes passed through the Highland Park section of Pittsburgh, near the Pittsburgh Zoo, on Friday. According to a statement from the zoo’s social media, no animals, personnel, or guests were harmed, and the zoo reopened on time the following day.

“The zoo experienced multiple downed trees, several damaged fences, a power outage, and toppled objects, branches, and debris throughout the park,” wrote the zoo on its Facebook page. “A large tree fell on a vehicle in our parking lot. Buildings were not significantly damaged.”

According to meteorologist Jason Frazier of the National Weather Service in Pittsburgh, the peak of tornado season hasn’t even arrived yet.

“Typically, June tends to be the month with the greatest frequency of tornado activity,” Frazier said. “Through 2022, we've had 93 tornadoes reported on record in the month of June, which is 22 more than the next highest month, which is July.”

Frazier said this season, the region just happens to be experiencing many of the weather patterns required for tornadoes to form — a combination of warm, moist air and cool, dry air.

“We've just been in a pattern where we've had a warmer spring, and we've had moisture while having various low-pressure systems moving through,” Frazier said. “It just so happens that this year we've had the right combination of ingredients in place to lead to tornado genesis.”

Of those 19 tornadoes, three of them were rated at EF2 on the Enhanced Fujita scale, which measures the strength of a tornado. These struck Monroe County, Ohio; Washington County, Pa.; and one that swept through Jefferson, County, Ohio, Hancock County, W.Va., and Beaver County, Pa. The remaining 16 twisters were rated at EF1 or lower.

According to the Enhanced Fujita scale, an EF2 tornado creates “considerable damage,” and produces winds of 111 to 135 miles per hour. The scale goes as high as EF5.

Butler County has had brushes with dangerous tornadoes in the past. Those who have lived here long enough will remember May 31, 1985, when a tornado swept through the heart of Butler County, leading to six deaths in Saxonburg and Evans City.

“I remember it because it came through my town,” said Steve Bicehouse, Butler County’s emergency director, who lived in Evans City at the time. “It came down through Harmony, Jackson Township, Forward Township, and Evans City.”

The 1985 twister was one in an outbreak of storms that swept through the Northeast United States and Ontario that day, leading to a total of 90 deaths.

Tornadoes have touched down in the county in recent years, though not quite as intense as the one from 1985. On October 2021, two tornadoes swept through Butler County on the same day — one striking Harmony, the other landing in East Butler. The Harmony twister was an EF1, while the East Butler tornado was an EF0. Neither caused any injuries.

Two years earlier, in June 2019, an EF1 tornado swept through Parker Township in the northern part of the county. Again, no injuries were reported, although dozens of trees were uprooted.

On April 17 this year, Butler County was put under a “tornado watch” during a severe storm. While no tornado actually resulted, Frazier said the watch simply meant the conditions for a tornado existed at the time.

“A tornado watch means that there are certain ingredients in place that would allow for tornadoes to form,” Frazier said. “That doesn't mean it's imminent or about to happen. But all your ingredients are in place for tornado genesis to occur.”

A tornado watch is one step down from a tornado warning, which indicates that a tornado is on the way in the area.

“A warning means you need to take action now,” Frazier said. “It’s time to find shelters and seek safety because the threat is more imminent.”

In the event of a serious twister, Butler County residents can be notified as soon as possible, thanks to the CodeRED notification system which residents can opt into.

“It's free for people to sign up,” Bicehouse said. “They can go to the county website and sign up, or they can call our office and we can walk them through it.”

Even in regions without a history of serious tornadoes, it never hurts to be prepared for one. That means putting a plan in place long before a tornado arrives, and stocking up the necessary supplies, such as bottled water, non-perishable food, flashlights, a battery-powered radio, and a seven-day supply of food.

According to Bicehouse, the safest place to be during a tornado is underground and away from windows. If no such space exists in your residence, a bathroom or closet is the best alternative.

“Understand what sort of actions you will need to take, because when you’re in the heat of the moment, it's going to be a little bit harder to start collecting the items you need,” Frazier said. “That way you can more quickly get to a safe shelter and reduce the amount of time that you're going to potentially be at risk to the impacts of a tornado.”