Flash Flood in Blair County, Pennsylvania

Flash flooding and water across the roadway led to the closure of Pleasant Valley Boulevard in Altoona.

A low pressure system stationed along the Hudson Bay allowed for central Pennsylvania to experience a brief period in the warm sector during the afternoon hours of June 9, 2025 ahead of a mid-level trough. This trough aided in large-scale ascent ahead of a surface cold front that aided in supercell development across western and central Pennsylvania during the afternoon and evening with the trailing cold front, allowing for a second round of thunderstorms containing locally heavy rainfall and some severe thunderstorms that produced wind damage. Locally heavy rainfall in Altoona led to multiple roadways in and around the city becoming impassable with States Road quickly being washed out by the rainfall. Later in the evening, two supercells formed across the central mountains of Pennsylvania, with the southernmost one producing large hail in Mifflin County and producing widespread tree damage in northern Huntingdon County. The northernmost supercell produced multiple trees and wires down in Milesburg. An isolated severe thunderstorm also knocked down two trees into a residence in northern Perry County, with no injuries reported. Heavy rainfall also caused isolated instances of flash flooding in central Bedford County and northern Huntingdon County, with flooding reported in Perry County during the early morning hours of June 10th.