A small but powerful rain and hail storm settled over the McKinley Village area on Wednesday night, smashed plants in gardens and damaged some local roads with heavy runoff from the torrential downpour. Some of that hail remained evident in shady areas through the following day.
A local meteorologist called it a unique event, something that happens maybe once every 10, 20 or 30 years. David Arnold publishes the Denali/Healy Weather Blog on Facebook and periodically shares his expertise on current weather conditions.
This storm was unusual, in part because it lasted so long and that it lingered over the McKinley Village area, he said. McKinley Village is a neighborhood located seven miles south of the entrance to Denali National Park, along the Parks Highway.
As much as 3 inches of rain was recorded, he wrote. Rainfall began at about 7:25 p.m. and ended at 9:54 p.m., with thunderstorms happening during that period.
Pea-size hail fell from about 7:37 p.m. to 7:55 p.m. and perhaps longer in other areas outside of his weather station. He also recorded hail accumulation of 1/4 to 1/2 inch.
Heaviest rainfall was 0.18 inches in five minutes from 7:39 p.m. to 7:44 p.m.
“This is a very impressive rainfall rate for anywhere in Interior Alaska,” he wrote.
He also reported 21 cloud-to-ground lightning strikes, 14 of which were “positive” strikes. Positive strikes last longer than negative strikes and are capable of starting wildfires.
“So it was very helpful to have so much rain so quickly with that many positive lightning strikes,” he wrote. “It was also quite unusual to see 66 percent of the lightning strikes in a storm be of positive character as it’s usually much less than even 33 percent, so this too was impressive.”
The storm was also unusual, he said, because it recycled air in and out of the storm system. It’s not unusual for that to happen for five or 10 minutes, but “a near two-hour period of time is extremely unusual in Alaska,” he said.
Reach columnist/community editor Kris Capps at firstname.lastname@example.org. Follow her on Twitter @FDNMKris.