Severe thunderstorms rumbled through much of southern Maine on Saturday afternoon, downing trees and power lines, causing at least one fire and disrupting a lobster roll festival.

The heaviest winds and rain came through Greater Portland about 2 p.m., said John Cannon, a meteorologist with the National Weather Service in Gray.

Severe thunderstorm and flash flood warnings had been issued for parts of York, Cumberland, Somerset and Franklin counties. The storms were carrying 60 mph winds and penny-sized hail, the weather service said. Most warnings were lifted by midafternoon, but a special weather statement warning of small hail and gusty winds for the Lakes Region was still in effect at 5:30 p.m., Cannon said. That warning had been lifted by 7:30 p.m.

In Westbrook, firefighters responded to a fire on the roof of a home at 26 Clifford St. about 2:30 p.m. that officials say was caused by a lightning strike. Firefighters contained the fire quickly, according to the Westbrook Fire Department’s Facebook page. No injuries were reported.

The storm blew down trees and power lines on Valley Road in Cumberland, shutting down a section between Homestead and Thurston roads. Cumberland police advised motorists to use Bruce Hill Road instead.

Tents and tent frames were blown over at the Down East Lobster Roll Festival on Thompson’s Point, on the Fore River in Portland. On Twitter about 3:30 p.m., Portland police posted pictures and videos of the damage caused by the heavy winds. Police said the area was evacuated before the storm blew through and no one was hurt. The festival, scheduled for noon to 5 p.m., was sponsored by Down East magazine.

Later in the afternoon in York, after storms had left that area, gusty winds helped to topple a moving camping trailer, police said.

The camper was being towed by a pickup truck in the northbound lane of the Maine Turnpike just south of the Ogunquit line around 4:30 p.m. When the pickup tried to pass another vehicle, the camper began to fishtail and wobble and eventually flipped on its side, said Trooper Gavin Hager of the Maine State Police.

The pickup driver managed to pull into the breakdown lane, with the camper on its side but the truck still upright, Hager said. No was hurt but emergency crews responded, partially to check the condition of a passenger in the truck, who was eight months pregnant, Hager said.

Because the camper landed in the breakdown lane, traffic was not affected in significant way, police said.