Severe winds hammer Southcentral

The winds caused flight cancellations, power outages and local road closures

Winds of up to 58 miles per hour were reported in Kenai over the weekend as severe wind wreaked havoc throughout Southcentral Alaska. The winds prompted the temporary closure of Escape Route and Marathon roads north of the Kenai Municipal Airport — the road reopened Monday morning — caused power outages across the peninsula and delayed or canceled flights for people trying to fly into Kenai.

The extreme weather continues to pummel residents in the Matanuska-Susitna Valley, where the Mat-Su borough signed a disaster declaration Monday and where more than 22,000 customers were at one point without power.

The National Weather Service Anchorage bureau shared a graphic on Sunday at around 8 p.m. that showed the peak wind gusts for regions throughout Alaska over the previous 48 hours in miles per hour. Kenai’s peak wind gust for that time frame was northern winds of 58 miles per hour. That’s compared to Soldotna, which experienced peak northern winds of 39 miles per hour and Seldovia, which reported peak winds of 49 miles per hour from the north.

In the Mat-Su, the Glenn Highway Interchange saw peak gusts of 91 miles per hour, the Glenn Parks Interchange saw peak gusts of 85 miles per hour, Thompson Pass saw peak gusts of 76 miles per hour and Wasilla saw peak gusts of 74 miles per hour.

Gov. Mike Dunleavy issued a disaster emergency Monday for the Mat-Su Borough, the Fairbanks North Star Borough including Nenana, the Denali Borough and the Delta/Greely and Copper River REAAs. That declaration activates the State Public Assistance and Individual Assistance program, which provides assistance to individuals or families to meet disaster-related needs, according to a release from Dunleavy’s office.

The strong winds similarly caused power outages across Southcentral Alaska, including on the Kenai Peninsula, where Homer Electric Association Inc. worked through the weekend to help restore power. The company reported a peak impact of about 4,000 customers experiencing outages on Saturday at around 8:45 p.m., but the total number of customers impacted fluctuated between 2,800 earlier that day to 1,050 on Sunday evening.

Over the weekend, outages were reported from customers in Nikiski, Sterling, Kasilof, Kenai and Soldotna, the company said. As of about 12:45 p.m. on Monday, HEA’s outage map showed 35 customers without power, most of whom were concentrated in Kenai.

HEA Director of Member Relations Keriann Baker described responding to outages over the weekend as being like a “giant game of whack-a-mole.”

“As soon as we would fix one area, … we’d have more outages popping up in other areas,” Baker said. “In some cases, we restrung the same line three or four times.”

HEA has six lineman in Homer and eight in Kenai, but the company also works with private contractors, Baker said. Crews were rotated over the weekend and additional crews were brought in from Anchorage to help respond to outages.

Baker said HEA expects more outages as wind shifts to the Kenai Peninsula, but that those outages aren’t expected to be as bad because weather is not expected to be as severe. In the future, Baker said people can proactively help prevent outages by clearing dead vegetation from their property — especially spruce bark beetle kill trees, which she said HEA’s seen a lot of in north Kenai. She also reminded people never to approach downed power lines.

The winds also caused delayed or canceled flights, which left some peninsula travelers stranded in Anchorage.

Ravn CEO Rob McKinney said Monday that while the company doesn’t have an exact figure for the number of flights delayed or canceled over the weekend, there was a difference of about 30% in the company’s on-time flight performance when weather was taken into consideration. Kenai Municipal Airport Manager Eland Conway confirmed Monday that there were delayed and canceled flights over the weekend, but said it was due to runway conditions in addition to weather.

Ravn’s primary safety concern, McKinney said, is crosswind to the runway, or wind that is blowing perpendicular to the runway as well as the resulting impact it can have on the runway itself. During the time that elapses when a flight is delayed, McKinney said crews are kept alert and planes are kept ready if conditions improve.

“The second that the weather changes, we can load people up and go as quickly as we can,” McKinney said.

There is a maximum amount of crosswind every plane is designed to handle, McKinney said, adding that it ultimately is not beneficial for Ravn to postpone or cancel its own flights.

“It does us no good to not fly flights or to fly flights late,” he said.

Aviva Braun, a meteorologist with the National Weather Service in Anchorage, said Monday that the wind event impacting the Mat-Su Borough is the same one that was felt on the Kenai Peninsula, but to a lesser extent.

The severe winds are caused by a really cold, polar arctic air mass that is currently sitting over the Yukon, Braun told the Clarion on Monday. Cold air is dense, which leads to higher pressure. There’s also a warmer air mass currently sitting over the Gulf of Alaska. The temperature difference between the two is big enough that there is a strong pressure differentiation between the two areas.

“Basically, the cold air from the Yukon is coming through all the valleys through the mountain passes from the Yukon, and is headed toward the Gulf (of Alaska), hitting through this area on the way there,” Braun said. “That really cold dense air is basically rolling down these hills and speeding up as it goes.”

One way to think about it, Braun said, is like a topographic map. In the same way lines on such maps represent differences in elevation, there are “lines” of pressure between the Yukon and the Gulf that represent pressure.

“Just like you would see on an elevation map — the more compact those lines are, the steeper the climb — the more compact the pressure lines are, the stronger the wind,” Braun said.

The Mat–Su is taking the brunt of the wind, Braun said, because the valley is oriented northeast to southwest. That’s compared to Kenai, where the wind was less severe because wind isn’t being funneled through a narrow passage.

Braun said during a press conference held by the Matanuska-Susitna Borough on Monday that the winds hammering Southcentral are part of a bora wind event that is comparable to other historical wind events in Alaska. As of 10 a.m. on Monday, Braun said the Mat-Su had experienced 48 consecutive hours of strong winds, making it the fourth-longest bora wind event in the Palmer/Wasilla area.

The third-longest bora wind event, Braun set, was experienced in February 1979, when 51 hours of strong winds and gusts of 79 miles per hour were recorded at the Palmer Airport.

A high wind warning remained in place for the Mat-Su area through at least Wednesday evening. Up-to-date weather alerts for Southcentral Alaska can be found at weather.gov/afc/.

Reach reporter Ashlyn O’Hara at ashlyn.ohara@peninsulaclarion.com.