The National Weather Service says that damage in Northeast Philadelphia was caused by an EF-0.
The building damage at Northeast Avenue and Red Lion Road was the result of a tornado, with peak winds of 75 m.p.h., according to the National Weather Service.
Weather service meteorologist Joe Miketta, the investigator in the scene, found evidence of rotational winds, just as radar images had suggested.
Officially, it was an EF-0 on the enhanced Fujita scale, said his colleague, Dean Iovino. The weather service said it traveled about 300 feet and cut a damage path of about 100 feet.
Confirming a tornado isn't just about morbid curiosity, said Iovino. For one thing, it has scientific value in verifying that the expensive radar equipment isn't hallucinating.