This story has been updated.
Cooler weather is keeping some massive ice jams in place on the Aroostook River as flood threats persist.
A 2-mile-long jam between Castle Hill and Wade could cause additional flooding as the ice shifts, according to the National Weather Service.
That jam is one of the three that are left in Aroostook County, according to meteorologist James Sinko at the weather service in Caribou. The others are in Fort Fairfield and St. Francis. Last week’s warmth allowed things to move quickly, but the ongoing cold spell means melting will take a long time.
“There are two ways to break up an ice jam: thermal or mechanical,” Sinko said. “We’ve got to rely on Mother Nature to thermally decay it, or warm it up. It needs to melt at the point where it can break free.”
The Castle Hill-Wade jam started March 21 and has been about the same length since then, he said.
It’s also stuck on the river’s Donnelly Island. The chunks are so big and thick that as they shifted, they sank into the riverbed. Until enough melting happens, the jam isn’t going anywhere.
A flood advisory issued Wednesday night by the weather service was canceled Thursday morning. Emergency management officials reported waters had receded near Gardner Creek in Wade, camps were accessible and flooding there was no longer considered a threat.
Waters had also moved back in Fort Fairfield and Caribou, and Grimes Road is now open to traffic, Fort Fairfield Police said Wednesday afternoon. Crews have cleared ice from the road, but motorists should be cautious because portions of the road may be damaged.
Near St. Francis and St. John Plantation, a 5- to 6-mile jam is frozen in place on the St. John River.
“Thankfully, water levels have come down, water is finding a way around it and it isn’t causing any road closures at this point,” Sinko said. “It’s just stuck and got nowhere to go at this point.”
Every other river in northern and eastern Maine is clear, he said. But with cool temperatures and little sun forecast for the next few days, northern Maine ice jams could cause problems for another week or so.
Aroostook County Flood Watch, a social media page operated by Aroostook Emergency Management Agency, reported little movement of the mass on the St. John River.
Officials encouraged people to prepare for recurring flooding until all the ice has cleared.
