Extreme weather is a common thing in the Commonwealth of Pennsylvania. It’s responsible for several disasters in the state. If you’re planning on relocating to or visiting Pennsylvania, you may want to know, can Pennsylvania get tornadoes?
Pennsylvania isn’t part of the Tornado Alley. But it experiences an average of 16 tornadoes yearly, mostly in May, June, and July. The number has been increasing recently, with October witnessing more tornadoes. However, the frequency and intensity of tornadoes in Pennsylvania are still average.
Tornadoes require specific conditions to form, and these conditions exist in Pennsylvania. But other disasters, such as flooding and severe storms, affect the state more. Here, we discuss whether Pennsylvania gets tornadoes.
Tornadoes in Pennsylvania
Tornadoes happen in Pennsylvania and have been occurring more frequently in recent times. The state has experienced several tornadoes, including some that are major. Most tornadoes here happen in the western part, and July appears to be the preferred month for tornadoes in the state. However, May and June come close. While most of the tornadoes usually happen in the spring, between March and July, Pennsylvania is now seeing tornadoes at odd times, such as in October.
These three months experience the most thunderstorms in the state. Since thunderstorms play a role in tornado formation, it’s not surprising. Months with the least tornadoes historically in the state are December, January, and February. December has zero tornadoes on record.
The number of tornadoes in Pennsylvania has been increasing significantly in recent years. Between 1950 and 2020, the Pittsburgh National Weather Service office recorded only 11 tornadoes in October. But in October 2021, it recorded 28 tornadoes, 16 in Pennsylvania alone. The office covers parts of western Pennsylvania, eastern Ohio, and northwestern Virginia.
Overall, Pennsylvania experienced 984 tornadoes between 1950 and 2021, showing the frequency of tornadoes in the state. Most of these tornadoes are low-impact EF-1 tornados, causing minimal damage. But the state also experiences tornadoes of EF-3 category and above. Only one F5 tornado has ever landed on the city.
When it comes to the frequency and intensity of tornadoes, Pennsylvania is an average state. It ranks 25 for how often it happens with an average of 10 between 1950 and 1995. Within that period, it also ranks 22 for injuries, 21 for the number of deaths, and 13 for the cost of damages.
The worst tornado to ever hit Pennsylvania was the one on May 31, 1985, which affected the northeastern US and Canada. Forty-three tornadoes happened in total, with 21 being in Pennsylvania. 10 of the 43 were F4 and F5 tornadoes, leading to 89 deaths in total, 65 of whom were in Pennsylvania. The tornado was the deadliest in the 80s.
What You Should Know About Tornadoes
Several factors work together before a tornado can happen. These include warm moist air, strong storm frost, and the right weather pattern to aid the spinning of the air masses. All these conditions are possible in Pennsylvania. Tornadoes usually emerge from severe thunderstorms, and hail usually follows the tornado. The most destructive tornadoes come from giant thunderstorms known as supercells. Only one in a thousand storms become a supercell, and it takes one in every five to six supercells to form a tornado.
Although the Tornado Alley experiences the most tornadoes in the US, this disaster isn’t native to that area. Every state of the US has experienced tornadoes. However, Texas has the most, with an average of 120 tornadoes annually. In addition, the US experiences the most tornadoes annually.
There’s no specific time of the year for tornadoes to happen. So, they can happen anytime. But they mostly happen in the spring, especially in the states along the Gulf of Mexico. In the country’s northern parts, tornadoes happen more frequently in the summer.
The duration of a tornado on the ground isn’t static. It could take a few seconds or several hours. However, the average has a width of 660 feet and moves at a speed of 30 mph. Most tornadoes won’t go beyond 6 miles before subsiding. But the most destructive tornadoes can go as fast as 300 mph and last for hours. The speed of a tornado is merely an estimate since anemometers are incapable of recording the speed of a tornado. It can’t stand the force.
The Fujita scale measures the intensity of a tornado based on the damage it causes and assigns a scale between F0 and F5. But since 2007, states have started using the Enhanced Fujita scale, which considers several other variables to determine the tornado’s speed.
How Tornado Forms?
Tornado forms when there’s a collision of warm, humid air and cold, dry air. The cold air, which is usually heavier, is pushed over the warm air to produce thunderstorms. Then the warm air passes through the colder to form an updraft which will start rotating should the wind sharply change direction or speed.
If the rotating updraft called mesocycle draws more warm air into itself from the thunderstorm, the speed will increase. The strong wind and cool air from the jet stream can further increase the speed and intensity of the tornado. Most air in mesocyclone contains water droplets which will form a funnel cloud. If the funnel cloud can grow till it fully forms and descends from the cloud to the ground, it becomes a tornado. High winds and severe thunderstorms herald a tornado or come with it.
Other Natural Disasters in Pennsylvania
Apart from tornadoes, Pennsylvania also experiences other natural disasters. They include:
This is the most common natural disaster in the state. The heavy rainfall, rapid snowmelt, dam failure, and overflowing rivers cause flooding regularly in the state. Flash floods also happen often here, and several dams in the state are considered high hazards.
2. Severe Storms
The state experiences several kinds of storms, mostly due to its climate. Lightning fatality in the state is the highest, and there’s still hail, high winds, and thunderstorms. Tropical storms also affect the city from the indirect hurricanes affecting coastal areas. Snow storms and blizzards also happen here during the winter.
Tornadoes are one of the common natural disasters that happen in Pennsylvania annually. Most times, they have minimal impacts. But they can be quite devastating on many occasions too. Other weather disasters, such as landslides, wildfires, and earthquakes, are rarer and not as dangerous. Still, it’s important to prepare for all these disasters.