Portland officials warned residents to take precautions late Thursday afternoon after the city was hit by what was described as a “dangerous lightning storm” that sent at least one man to the hospital.

Powerful thunderstorms had widespread impact in Maine on Thursday, including a house fire in Berwick caused by a lightning strike and the cancellation of classes in the Five Town Community School District in the Camden area because Wednesday night’s storms cut power.

Police reported an injury in Appleton when a tree fell on a recreational vehicle late Wednesday night. No details were immediately available.

Portland spokeswoman Nicole Clegg said Thursday’s fast-moving storm, which blew through Portland around 3:45 p.m., triggered multiple fire alarms and reports of lightning strikes.

Clegg said a Peaks Island resident was taken to a local hospital after lightning struck the man’s home. His injuries were not considered life threatening.

Firefighters investigated alarms that went off at the former St. Joseph’s Convent on Stevens Avenue and at 149 Allen Ave., a senior housing complex in North Deering. No damage or injuries were reported at either site.

The Portland Fire Department reminded residents that if they can hear thunder, they are in danger of being struck by lightning. Individuals should immediately seek shelter.

Thursday’s storms followed severe thunderstorms across the state Wednesday night, with the National Weather Service reporting more than 1,000 lightning strikes occurring every hour.

The weather service in Gray issued a flash-flood watch for much of southern Maine for Thursday night.

Wednesday’s lightning was cloud to ground, the weather service said, more dangerous than cloud to cloud because of the potential to cause structural damage.

The storms also produced heavy rain, hail and wind speeds approaching hurricane force. Damage was heaviest in Knox and Waldo counties and on Islesboro particularly, said John Jensenius of the weather service in Gray.

Hail measuring an inch in diameter was reported in Windham.

More than 10,000 Central Maine Power Co. customers had lost power late Wednesday, though by Thursday afternoon there were fewer than 4,400.

“The storms are widespread and are producing winds in excess of 70 miles per hour,” said Eric Schwibs, a meteorologist with the National Weather Service in Gray, around 11 p.m. Wednesday. “That type of wind can cause a lot of damage.”

The strongest wind gust reported Wednesday was 62 mph in Cape Elizabeth and the most rain was recorded in Cumberland Center, 1.31 inches.

Earlier in the day, the weather service in Caribou issued a tornado warning.

Witnesses, including an Aroostook County sheriff’s deputy, reported high winds and widespread damage in the town of Oxbow, west of Houlton and just north of Baxter State Park.

Darrell Crandall, chief deputy sheriff for Aroostook County, said deputies, forest rangers, state troopers and workers from the Maine Department of Transportation spent more than three hours clearing a three-mile stretch of Route 11 of fallen trees and debris.

Though no tornadoes were seen, Rich Norton, a meteorologist with the weather service in Caribou, said a team of investigators will go to Oxbow on Thursday to assess the damage and try to determine whether a tornado touched down.

A National Weather Service spokesman said on Thursday that heavy rain and fog in Aroostook County delayed the inspection, which is now likely to occur on Friday.

The Knox County Sheriff’s Department confirmed that a tree went through a trailer at the Sennebec Lake Campground in Appleton and injured one person late Wednesday.

This story will be updated.

Staff Writer David Hench contributed to this report.

Dennis Hoey can be contacted at 791-6365 or at: [email protected]

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