Stay off the ice: Allegheny River frozen for more than 45 miles north of Cheswick

Recent clear and frigid nights accelerated ice formation on the Allegheny River stretching from Cheswick north past Kittanning, according to the National Weather Service.

With more than 45 river miles iced over, authorities are urging residents to stay off the ice for safety reasons.

The ice mass is expected to grow over the weekend.

The Army Corps of Engineers this week temporarily closed its Allegheny River locks in West Kittanning (No. 7), Boggs Township (Mosgrove, Lock No. 8) and Madison Township (Rimer, Lock No. 9).

The closure is necessary to protect the facilities and minimize risks to Corps staff, said Andrew Byrne, a spokesman for the Army Corps.

The National Weather Service issued a special statement about the Allegheny River ice Wednesday because of the growing number of recent reports.

Since there are no ice jams, which can cause flooding and property damage, the ice’s primary threat is to people who walk on it.

“We highly encourage people to not go onto the ice,” said Michael Mollick, director of public safety for Armstrong County.

There are too many unknowns for river ice, including thickness and variability in thickness, he said.

Ice thickness ranged from 1 inch to more than 6 inches, according to the weather service’s statement Wednesday.

Anyone who ventures onto the ice should wear a life jacket, Byrne said.

If residents see river ice jamming up or someone going into the river, they are urged to call 911, Mollick said.

Reports of the ice started to surface mid-month when night temperatures plummeted to single digits, according to the Corps and the weather service.

What seems to be the worst of winter is on time, said Jason Frazier, a meteorologist with the National Weather Service in Moon Township.

Historically, on average, January is the coldest month of the year in the Pittsburgh region, he said.

The frosty air is not breaking records but is freezing rivers.

“The colder air temperatures and light winds promote the ideal environment for ice development,” Frazier said.

Frazier predicts the ice will grow during the weekend, when temperatures are forecast to dip into the single digits and, on a few nights, hover at 1 degree or colder.

A warmup early next week will stop the ice buildup, he said. But beyond that forecast, it’s too early to tell when temperatures will be warm long enough for the ice to recede, Frazier said.

The Corps and the weather service will continue to monitor the ice in the event of an ice jam.

The Corps will conduct routine inspections at the locks and dams. They will reopen the upper locks once the ice conditions on the river improve, Byrne said. But the Corps cannot estimate when that will be.

The upper Allegheny River locks are operated by appointment only. There are no appointments scheduled, Byrne said, so the ice is not causing delays to navigation.