HALLOWELL, Maine — Volatile ice caused by unseasonably warm days followed by brutal cold caused turmoil for people throughout the state Sunday.

Along Water Street in Hallowell, where the Kennebec River frequently floods each spring, the water rose within minutes early Sunday morning, leaving close to a dozen cars partly or completely submerged.

“The river was very stable yesterday, all throughout the day,” said Eric Nason, Hallowell’s director of emergency management. “Then late last night it decided to jam.”

A large ice jam formed just downriver in Farmingdale, and the water just backed up.

Most storekeepers were prepared, he said, because they flood so often. But they don’t often deal with jams of this size.

Upriver from Hallowell, the Augusta Police Department posted photos on Facebook of cars underwater, warning that Front Street in the city had been closed since Saturday night.

In a release Sunday, Augusta police Sgt. Christian J. Behr said the river, at 16 feet rather than the usual 12 feet, was expected to run above flood level through Monday.

“Flood waters have entered the buildings on the north end of Front Street,” the release said.

Police encouraged people to use extra caution around flooded areas, especially where ice is present.

Also in Augusta, a Capitol Police cruiser was damaged Thursday night after snow and ice slid off the roof of the State Entomology Lab on Hospital Street in Augusta, according to the Kennebec Journal. The officer was uninjured.

The National Weather Service in Caribou issued a flood warning for the Penobscot River at Eddington from late Sunday to late Tuesday night or until the warning is canceled.

The river was at 17.4 feet at 8:30 a.m. Sunday, with flood stage at 18 feet.

The river was forecast to rise above flood stage after midnight Sunday and continue to rise to near 18.3 feet by early Monday afternoon, then fall below flood stage by Tuesday evening.

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