National Weather Service Confirms Tornado Activity in Jefferson and Clearfield Counties

The National Weather Service (NWS) State College office has confirmed that at least three tornadoes touched down in parts of Jefferson and Clearfield counties on Saturday, July 18, 2020. Survey teams deployed to the region determined the storms caused significant structural damage and downed numerous trees across the affected areas.

Survey Results and Tornado Ratings

According to NWS State College, the assessment confirmed three distinct tornado tracks resulting from the severe weather system. Meteorologists utilized ground surveys to analyze debris patterns and structural damage to assign intensity ratings on the Enhanced Fujita (EF) scale.

The first tornado, which struck near Reynoldsville in Jefferson County, was rated an EF-1 with estimated peak winds of 105 mph. The second and third tornadoes were confirmed in Clearfield County. One of these was also categorized as an EF-1, while the final tornado was rated as an EF-0, with wind speeds estimated between 65 and 85 mph. These ratings indicate the severity of the wind damage inflicted on local infrastructure and vegetation.

Impact on Local Infrastructure

The storms resulted in widespread debris that blocked roadways and disrupted power grids throughout the weekend. Local emergency management agencies reported that the damage was largely concentrated in rural sections of the counties, where the tornadoes downed trees and damaged outbuildings.

Cleanup efforts began immediately following the storms, with utility crews working to restore electricity to residents affected by snapped power lines. No fatalities were attributed to the tornadoes in the immediate aftermath, though local officials cautioned residents to remain vigilant regarding storm debris and lingering hazards.

Understanding Tornado Ratings

The NWS uses the EF scale to categorize tornadoes based on the damage they cause, which serves as a proxy for wind speed. The scale ranges from EF-0, which causes light damage, to EF-5, which involves total destruction.

• EF-0 (65-85 mph): Minor damage to roofs, gutters, and siding; tree branches broken.
• EF-1 (86-110 mph): Moderate damage; mobile homes may be overturned, and roof surfaces may be stripped.
• EF-2 (111-135 mph): Considerable damage; frame homes may shift or lose roofs, and large trees may be snapped or uprooted.

Historical Context for Central Pennsylvania

While tornadoes are less frequent in the mountainous terrain of Central Pennsylvania compared to the Great Plains, the region remains susceptible to severe weather during the summer months. According to National Oceanic and Atmospheric Administration (NOAA) climate data, July is a peak month for convective storm activity in the Commonwealth. The July 18 event serves as a reminder for residents to maintain access to weather alerts, particularly during high-heat and high-humidity days that often precede rapid thunderstorm development.