Tornadoes are one of the most destructive natural phenomena in the world. They can wreak havoc on communities and cause billions of dollars in damage to property and crops.
While tornadoes can occur anywhere, certain areas of the country are more prone to them. Pennsylvania is no exception.
Tornadoes can be destructive, tearing down homes and businesses, uprooting trees and hurling objects through the air. The most important thing is to take cover if you hear or see one.
In the event of a tornado, it is always better to seek shelter in an area that has basements or storm cellars. If you live in a high-rise building, find an interior room on the lowest floor without windows.
The National Weather Service has confirmed that a tornado hit Upper Dublin Township, Fort Washington and Horsham Township in Pennsylvania Wednesday night. It left a devastating impact on the township, damaging stores and restaurants, according to reports.
A second tornado raked Greene County, Pennsylvania, on Friday afternoon. It touched down near Graysville at about 7:35 p.m. and ripped off roofs and snapped dozens of trees. It caused extensive damage to a handful of farms along Mapleshade, Rosedale and Highland roads northeast of Kirkwood. Several fire companies in the area spent hours cleaning up the damage.
Tornadoes can happen at any time of year, but April, May and June are the peak months in which they are most likely to occur. This is a good time to review your tornado plan, which includes where you will take shelter and how you can protect your family from storms.
In addition, tornadoes are more likely to hit during the nighttime hours. People are often asleep and vulnerable during this period, making them more at risk of being caught unaware by a tornado.
The majority of tornadoes in Pennsylvania happen during the spring months of March, April and May. This is due to the fact that thunderstorms are more common at this time of the year and they tend to produce severe weather in the form of tornadoes.
In the last 50 years, a majority of tornadoes in Pennsylvania have occurred in counties that are relatively close to or in large metropolitan areas. That's because of ideal tornado-forming weather conditions that persist for long periods of time.
That's why the state has experienced more than 1,500 tornadoes in recent decades compared to the national average of about 1,000. That's more than double the number of tornadoes that occur in Texas, Kansas and Oklahoma.
Those numbers are based on unofficial statistics from the National Weather Service. They don't include tornadoes that didn't produce any damage, such as Wednesday's storm in Westmoreland County.
A tornado touched down in Washington County on Tuesday night with winds exceeding 85 mph, uprooting trees and damaging homes. It was about a mile wide at its largest point and lasted less than an hour.
Tornadoes can occur at any time, but they tend to be more common during the spring and summer. These storms are violently rotating columns of air that are dangerous because they have a lot of focused energy, according to the National Weather Service.
Tornadoes generally form in areas that are prone to thunderstorms and have enough moisture to create strong updrafts. This includes places like the Great Plains, where tornadoes are most common, and Australia, which gets about 100 a year.
These areas have a warm lower atmosphere beneath cold air aloft (the ingredients that favor intense thunderstorms), and they also get wind shear, which is wind variation that enhances storms and makes them more likely to rotate, said Paul Markowski, a Penn State meteorologist.
The combination of these ingredients, along with the jet stream that is still enhanced by El Nino, has resulted in a busy weather pattern this spring for many regions. That's led to an increase in tornadoes in places that weren't very prone to them before.