Pennsylvania Tornado and Severe Weather Climatology

NOTE: I am out of the office until Wednesday so I may be slow to respond to email or Facebook questions.

I traveled to Parker Dam in Clearfield County Pennsylvania Saturday night to assist with Henry Margusity'spublic talk - PowerPoint now available! on The Great 1985 Central Pennsylvania F4 Tornado that tore up and down the mountains of our state.

As part of that trip, I presented a PowerPoint Presentation called "Pennsylvania Tornado & Severe Weather Climatology." This presentation includes my discussion and maps of Tornadoes of Centre County and When Is Severe Weather Season in Central PA that I did last week, plus the following additional bullet points & maps:

- There Have Been 670 Tornadoes In Pennsylvania Since 1950 - Most Are Weak (95% Less Than F3, 75% Less Than F2 on the F-Scale)

When you start looking at very strong (F-4/F-5) tornadoes, much of that history was written on that fateful day of May 31, 1985:

- There Has Only Been One F-5 (Crossed In From Ohio In 1985) - There Have Been 8 F-4s, 6 Were In 1985; The Big One Was Furthest East

Note that there have been no very strong tornadoes in the eastern part of the state. This is mostly due to the fact that the strongest storms come into the state from the Ohio Valley and get torn up going over the mountains and dried out going down the hills. Eastern Pennsylvania can form its own strong thunderstorms, but they can't become that strong.

If you look at F3s, the distribution is more even (though the central part of the state continues to be a "tornado hole").

Those two maps were provided by TornadoHistoryProject.com.

- Strong Tornadoes (>F2) Are Rare in Central PA And Are Most Likely in May - But There Have Been F3s March-September

The facts above and below were put together using these graphs from the NWS's Pennsylvania Severe Weather Climatology Page.

- The Most Likely Time To See Severe Weather (Including Tornadoes) In PA Is Near 5 PM