(WHTM) — Following a brief tornado warning in York County on Monday afternoon, you might be wondering: how common are tornadoes in Pennsylvania?
Data from the National Weather Service’s website — which lists the Pennsylvania Emergency Management Agency, the National Weather Service, the Tornado History Project and the Weather-Ready Nation Ambassadors as sources — shows how many tornadoes have occurred in each Pennsylvania county from 1950 to 2022.
Here is the data for the Midstate:
Adams County: 17
Cumberland County: 16
Dauphin County: 19
Franklin County: 14
Juniata County: 7
Lancaster County: 35
Lebanon County: 19
Mifflin County: 5
Perry County: 6
York County: 32
It is important to note that the data for 2015 through 2022 is preliminary.
According to the graph, Westmoreland County, Lancaster County, Crawford County, Lancaster County, York County and Chester County are the only counties with 30 or more tornadoes from 1950 through 2022.
According to the National Weather Service Storm Prediction Center and the National Weather Service Public Information Statements, the months with the most tornadoes across the state from 1950 to 2019 are May with 144, June with 177, and July with 191.
The graph also lists the frequency of the tornadoes’ intensity, which uses the Enhanced Fujita (EF) Scale, with 0 being the lowest intensity and 5 being the most intense. The only recorded F5 tornado in Pennsylvania was in May of 1985.
Data that shows the number of Pennsylvania tornadoes by year from 1950 through 2019 shows that 1998 had the most tornadoes (by a longshot) with 61, followed by 1985 with 34, 1992 and 2018 with 32 each, and 2011 with 30.
According to the National Weather Service, 1998 is known as “The Tornado Outbreak of 1998” and specifically cites June 2, 1998, when nine tornadoes were confirmed in parts of southwest Pennsylvania, northern West Virginia, and Garret County, Maryland.
acb27’s meteorology team says the Midstate typically experiences two or three tornado warnings per year.