Storm leaves power outages across Anchorage and Mat-Su, with winds forecast to continue overnight

Update, 9 p.m. Saturday:

A powerful storm that socked Southcentral Alaska with powerful winds and heavy rain on Saturday knocked out power to thousands of dwellings in Anchorage and the Mat-Su, electric utilities reported. By evening, most of the outages had been restored, but windy conditions were forecast to persist across much of the region overnight.

As many as 1,800 dwellings in Anchorage were without power at one point on Saturday afternoon, according to Chugach Electric Association, but by 9 p.m. all major outages had been restored. Several thousand dwellings were without power in the Mat-Su early Saturday, but by late afternoon, power had been restored to most, the Matanuska Electric Association said.

A flood watch was lifted for the Anchorage area as rain let up across the city in the afternoon. High winds persisted across the area, however, and the National Weather Service said gusty conditions were likely to continue overnight from Turnagain Arm through Anchorage and out to the Knik River River Valley. Gusts from 45 to 60 mph were forecast for Turnagain Arm and the Anchorage Hillside, with gusts from 35 to 50 mph expected in Anchorage, Eagle River the the Knik River Valley, the weather service said.

Flood watches remained in effect in the Matanuska and Susitna valleys.

The storm was fueled by an atmospheric river that blasted wet, warm air into Southcentral Alaska from the North Pacific Ocean. Temperatures reached 70 degrees in parts of Anchorage late in the afternoon.

The power outages began Saturday morning and were being reported all over town by midafternoon, Chugach spokeswoman Julie Hasquet said. The association’s online outage map showed clusters of outages from East Anchorage to the Anchorage Hillside. Chugach did not have an estimate for when the repairs would be complete, but said multiple crews were out working, she said.

“The rain and the wind are bringing trees down into powerlines, and they got to find them, cut them up and get them out of there, make repairs and restore the power. So it’s a very dynamic situation,” Hasquet said.

Outages were also reported throughout Saturday by the Matanuska Electric Association. In Palmer, the Alaska State Fair cancelled a number of rides and events during the day due to the inclement weather.

Winds picked up around Anchorage starting Saturday morning with gusty conditions continuing through the afternoon, said National Weather Service hydrologist Marian Baker.

Peak gusts of nearly 60 mph were being recorded in Arctic Valley and Upper Potter Valley. At lower elevations across town, 25 mph winds with gusts to 50 mph were recorded, according to the weather service.

No flooding had been reported in Anchorage as of Saturday afternoon, Baker said

Earlier story:

A storm system that’s holding near-record amounts of moisture is bearing down on Southcentral Alaska for the weekend, bringing the potential for heavy rain in Anchorage and windy conditions at the Alaska State Fair in Palmer.

The National Weather Service issued a flood watch starting Friday afternoon into Saturday evening or Sunday morning across a broad area that extends from Homer and the Kenai Peninsula to the Susitna Valley, the west side of Cook Inlet and across the Copper River Valley. The agency warns that “excessive rainfall is possible” that could result in flooding in low-lying areas or places with poor drainage, as well as standing water on roads.

Forecasters say an unusually wet system is moving into the region from the Bering Sea and North Pacific Ocean. Weather balloons are registering significant moisture in the lower atmosphere, according to Weather Service meteorologist Michael Brown.

It’s not unusual to see rain in late August in Southcentral — rainy days at the fair are an Alaskan ritual — but the amount of moisture in this storm is higher than normal, Brown said.

“We’re seeing values that are near-record territory for this time of year,” he said Friday morning. “Since this is generally the wettest time of year, we’re seeing pretty much near-record moisture values.”

The atmospheric river that’s feeding wet weather is already here, but in Anchorage the rain is expected to pick up Friday evening into Saturday.

Rainfall totals in Anchorage could be 1 to 2 inches, according to current forecasts. That’s at lower elevations; higher elevations in the Chugach Mountains could see 2 to 4 inches, as could areas in the Talkeetna Mountains in Mat-Su. The Prince William Sound cities of Valdez and Cordova could also get 2 to 4 inches or more. The Susitna Valley could receive up to 2 inches of rain and the western Kenai Peninsula as much as 1 inch.

The unsettled weather is also expected to bring wind to places like upper Turnagain Arm that often see gusty weather during storms, Brown said.

“But also we might be seeing some pretty windy conditions at the state fair,” he said. “Especially as we head into Saturday maybe even Sunday.”

The heaviest rain in Anchorage is expected to end Sunday, though the forecast is in a familiar late August pattern: some chance of rain daily.