Accumulating ice on an electrical transmission line cut power Friday to Spokane International Airport, and a portion of the airport’s backup generating system failed to deliver an emergency supply for about 20 minutes.
The loss of transmission capacity to the airport and West Plains triggered brief power breaks in the downtown area about 11:10 a.m., according to Avista Utilities.
In addition, scattered power outages caused by the weight of accumulating ice across the Inland Northwest triggered a wider string of outages, including interruption of power to as many as 2,100 customers in northern Lincoln County.
Inland Power and Light Co., which also supplies power to the region, reported that 980 of its customers in Lincoln County and about 500 in the Newman Lake area lost power from a buildup of freezing fog and drizzle that was causing lines to sag and break.
“Our substations (in Lincoln County) look like ice sculptures,” Inland Power spokeswoman Catherine Markson said in an e-mail.
Spokane International Airport’s backup system failed initially in the A and B concourses, which were without power until the backup supply could be restarted manually, said Todd Woodard, airport spokesman.
Concourse C remained operating with its separate backup power system, he said.
Avista Utilities reported that about 4,000 customers lost power in the West Plains area, including the airport, from a pair of transmission line failures caused by ice weighing down the lines. The weight caused them to touch trees or the ground. The outages occurred about 10 a.m. and 11:10 a.m., with the latter outage affecting the airport and downtown, said Jessie Wuerst, Avista spokeswoman.
Power was fully restored in the West Plains area shortly after 2 p.m.
Elsewhere, a series of outages caused by icy weather were occurring in the Davenport and Wilbur areas, and the number of Avista customers without power was reduced from 1,150 to about 700 by nightfall. However, some outages may continue until today, Wuerst said.
At least 17 transmission poles were brought down by the weight of ice on two transmission lines in northern Lincoln County.
Inland Power reported that it was using five contract crews in Lincoln County, and that some of the outages may extend through the weekend.
Avista reported that it was moving crews to Lincoln County from elsewhere in the region to repair damage there.
Wuerst said a persistent weather pattern that’s bringing freezing fog and ice to the region could continue causing outages for the next several days.
Heavy buildups of ice on lines, trees and poles could worsen before the weather changes, she said.