Thousands without power in Mat-Su as high winds sweep through Southcentral Alaska

High winds across Southcentral Alaska that had already started causing power outages in the Matanuska-Susitna Borough on Saturday were expected to pick up overnight and into Sunday morning.

By Saturday afternoon, winds in northern and western Anchorage had reached gusts of up to 40 to 50 mph, according to a meteorologist with the National Weather Service office in Anchorage.

Blustery conditions in Mat-Su brought outages affecting over 13,000 Matanuska Electric Association members by 9:30 a.m. Sunday, according to the utility’s outage map. The outages dotted Matanuska Electric’s service area, from Chickaloon to Palmer and Wasilla up through Willow and Talkeetna. Crews were working to restore power amid “awful” conditions, the utility said.

In Anchorage, winds were strongest at Joint Base Elmendorf-Richardson, Ted Stevens Anchorage International Airport, around downtown Anchorage and in Turnagain on the west side of town, meteorologist Shaun Baines said.

Far fewer outages affected Anchorage on Sunday, with 55 Chugach Electric members without power across downtown and the University-Medical District, according to the utility’s outage map. On Saturday, about 125 Chugach Electric members in the Turnagain neighborhood were left without power for several hours, but power was restored by 6:30 p.m.

Along the Knik Arm and in northern and western Anchorage, high winds were expected to pick up Sunday morning, potentially reaching up to 60 mph, Baines said. A high wind watch for those areas will be in effect from 3 a.m. to 6 p.m. Sunday.

A high wind warning was also in place for the Matanuska Valley through 6 p.m. Sunday. Baines said gusts there could reach up to 75 mph, possibly contributing to hazardous driving conditions.

“There’s actually a chance that (the wind) might try to push your car into the lane next to you,” Baines said. “Just keep holding the steering wheel,” he said.

With such high wind speeds, Baines said it was important for large objects to be tied down and secured, and for small-plane owners to safely secure aircraft. The weather service recommended that people prepare for the possibility of power outages and local whiteout conditions.

On the Glenn Highway, blowing wind and snow caused “extremely poor” visibility Saturday afternoon, especially in the flats south of the Parks Highway/Glenn Highway interchange. The reduced visibility prompted Alaska State Troopers to partially close the highway and later set up an alternative route for thru-traffic, troopers spokesman Tim DeSpain said.

By late Saturday afternoon, northbound traffic was being routed along the Old Glenn at the overchange south of the Knik River while a pilot car was leading southbound traffic from the Palmer-side interchange through the flats, DeSpain said.

“There was numerous vehicles that had gone into the ditch. And so it was pretty messy at first as we got those vehicles out of the ditch, and cleared,” he said. “Once the vehicles were cleared from the roadway, then we started the pilot car process.”

DeSpain said the reroute was a temporary Saturday fix, and that the situation was fluid and could change with the weather.

A wind chill as low as minus 30 degrees heading into Sunday morning was possible in both Anchorage and the Matanuska Valley, according to the weather service.

The winds are being driven by a “bitterly cold air mass” from Interior Alaska that is moving southward across a wide swath of southern Alaska, Baines said.

As cold, dense air drops off a mountain range, it accelerates as it sinks, which is what causes high winds, Baines explained. That’s currently happening across most of southern Alaska — including Bristol Bay and the King Salmon area, which is seeing gusts up to 55 mph and a wind chill around minus 35 degrees, he said.

The Copper Basin area, Susitna Valley and Southwest Alaska were expecting wind chills as low as 40 degrees below zero Saturday night and Sunday night, Baines said.

“So it’s pretty brutal across a large section of Alaska right now,” he said.