How Likely Is a Tornado in Allegheny County, PA?
Allegheny County, PA: what NOAA's tornado record says
Allegheny County has recorded 28 tornado touches in NOAA's 76-year database, a rate of roughly one every 2.7 years - our Elevated band. Put another way: Allegheny County sees more tornado activity than 66% of US counties. Among 67 Pennsylvania counties in this dataset, Allegheny County ranks 8 for how often a tornado touches down.
Beyond the frequency band: violent history
1 tornado touching Allegheny County reached violent (EF4-5) strength since 1950. That single fact carries more weight for the shelter decision than the county's overall frequency band.
The dollar figure Allegheny County's rating leads to
Cost nationally: $2,890-$13,280, about $7,645 typical. Pennsylvania has no state rebate program confirmed here; FEMA's underlying 75% cost-share exists nationwide, but applying through a state program is what usually makes it real, and none was found for Pennsylvania this pass.
What a direct hit isn't required for
A direct hit is not required for Allegheny County to lose power - outbreak-wide outages across Pennsylvania regularly reach homes and businesses well outside the actual tracks. A battery bank covers that gap without a generator's fuel and venting needs.
What this number is, and is not
One caveat before relying on Allegheny County's number: it is county-wide, and it covers about 730 square miles, so a single touch counts the same as one in a county a fraction of that size. Weaker pre-1990s tornadoes are also documented as undercounted in NOAA's own record. Allegheny County has about 1,231,814 residents.