The high winds early Thursday caused power outages across the Keweenaw Peninsula, but service was restored to some customers by late morning.

Dave Forsberg, spokesman for Upper Peninsula Power Company, said as of 6:30 a.m. Thursday, customers in Calumet, Copper Harbor, Eagle Harbor, Eagle River, Laurium, South Range, Twin Lakes and Winona had lost electricity.

“Just in the Keweenaw alone we had about 3,800 customers without power,” he said.

Most of the outages were caused by tree branches falling on power lines due to the high winds. Despite the restoration of some power to some customers, Forsberg said power could go in and out because of the continuing high winds.

In Houghton County, Forsberg said as of 6:30 a.m., about 300 customers lost power. As of 11 a.m., power had been restored to all but 40 customers.

“As of 10:30 a.m., we’ve gone from 3,800 in the Keweenaw to just under 940,” he said.

Forsberg said how long it takes crews to repair downed wires depends on where they are. Some lines are in rugged areas, which are difficult to reach.

“We’re working as quickly as possible to get everybody on as soon as possible,” he said.

Dave Ptrovich, forecaster with the National Weather Service office in Negaunee Township, said the high winds were caused by a pressure difference between a high-pressure system over the northern Plains states and a low pressure system in Canada.

“We’ve got a really intense low-pressure area that’s situated over James Bay,” he said.

Since the high winds started at about 1:30 a.m. Thursday, Ptrovich said the highest recorded gust was 60 mph at Hubbell. Other recorded wind gusts were 56 mph near Twin Lakes, and 60 mph at the Houghton County Memorial Airport, with other gusts of 45 to 50 mph. He said the high winds wouldn’t last beyond Thursday.

“We’ll see the winds decreasing into early afternoon hours, then a rapid decrease into the evening,” he said.

Between 4 p.m. and 11 p.m. Thursday, Ptrovich estimated the gusts to be 15 to 25 mph. After 11 p.m., gusts would be down to 10 mph. There should be no significant wind Friday, which was mostly cloudy with a high about 31 degrees.