A rare Anchorage thunderstorm Thursday night knocked out power to thousands of people for the first time in years, the affected electric companies said.
Some 2,800 people in Mountain View and Muldoon lost power around 9:30 p.m. after lightning struck a power line in the area, said Julie Harris, a spokeswoman for Municipal Light & Power. The outage lasted about an hour.
It was the first time the power company had seen a lightning-related power outage in 15 years, Harris said.
Another lightning strike around the same time also caused a smaller outage in South Anchorage, according to the Chugach Electric Association, which supplies power to most of the Anchorage Bowl and the Hillside.
Company’s spokeswoman Julie Hasquet said a lightning strike that traveled through a power line there blew some fuses in a switch cabinet near Dowling Road and B Street, cutting power to about 500 people.
Hasquet said she didn’t know exactly how often the company sees lightning-caused power outages, but called them “very infrequent.”
In Midtown, Anchorage resident Corey Crow was driving south through the intersection at Fireweed Lane and C Street when his dashboard camera captured an image of lightning striking near a jet.
Crow said he didn’t realize the plane, which appeared to be departing to the east from Ted Stevens Anchorage International Airport, had been near the lightning strike until he reviewed the footage later.
The airport and the Federal Aviation Administration couldn’t be reached Friday to answer questions about whether a plane had actually been hit.
Lightning is unusual in a city that, according to National Weather Service meteorologist Michael Kutz, sees fewer than two thunderstorms a year. They’re most likely to happen in June or July, though Thursday’s thunderstorm was the first one since September 24, 2018, Kutz said.
That’s because a very specific set of conditions has to exist to create a thunderstorm, he said — an updraft of moist air, a sufficiently warm atmosphere, and a spin in the atmosphere creating energy, among other things. Anchorage’s geography makes those conditions difficult to create.
Alaska’s largest city has two primary strikes against it where thunderstorms are concerned: the temperature and the mountains. Coastal Alaska, which is cooler than the Interior during the summer months because of the ocean, tends to get fewer upward thermals, a necessary thunderstorm ingredient, Kutz said.
The Chugach Mountains also create what Kutz called a “rain shield” that blocks moist air coming in from the southeast. Thursday’s system managed, unusually, to find its way around the shield, he said.
“It just happened to hit in a nice little area, wormed its way up the Turnagain Arm,” Kutz said.
The brief storm spurred an equally-unusual hail fall in some places, with nickel-sized hail reported in Eagle River, he said.
However, the same features that make thunderstorms difficult to create also make them difficult to sustain. What little thunder and lightning Anchorage does get tends to dissipate rapidly.
“Basically it’s a big juggling act where you have to have all the balls in the air to get a thunderstorm, and if you drop one, no thunderstorm — you might get heavy rain or something like that,” Kutz said.
Thunderstorms were expected to continue until 11 p.m. Friday evening.