Larry Caruso writes on the Pentucket RA mailing list:
“As reported on WMUR Channel 9 this morning: the National Weather Service confirmed the wind event that damaged our tent at NEAR-fest was an EF1 tornado. It traveled at 50 mph for 36 miles.
“That helps explain the loud sound we heard as it approach and why other nearby sites weren’t damaged.”
See also: https://www.facebook.com/easternmaarrl/posts/588283388194369