Rare thunderstorms in Southeast Alaska led the National Weather Service to issue a special marine warning Monday evening.
The warning covered a swath of Southeast, roughly from Juneau to the southern tip of Prince of Wales Island.
Between about 5 and 6 p.m. Monday, a network of ground sensors detected more than 100 lightning strikes in the affected area and portions of western Canada, says Rick Fritsch, the weather service’s lead forecaster in Juneau.
“Boats of course, very susceptible because by definition, they’re out there floating on the water. They are the high spot,” Fritsch says.
The weather stayed clear in Juneau through the end of the warning at 7:15 p.m.; weather radar images showed the brunt of the storm system over Chichagof and Baranof islands, Chatham Strait and parts of Admiralty Island.
Juneau averages about one thunderstorm every two years, Fritsch says.
“This is kind of interesting because late Autumn going into the winter is normally when we see thunderstorm activity, coming at us from the gulf,” Fritsch says.
He says moist air from Canada combined with unusually high ground temperatures — Monday’s highs in Juneau were 16 degrees above normal — caused the atmospheric convection that led to the thunderstorms.
Jeremy Hsieh is the deputy managing editor of the KTOO newsroom in Juneau. He’s a podcast fiend who’s worked in journalism since high school as a reporter, editor and television producer. He ran Gavel Alaska for 360 North from 2011 to 2016, and is big on experimenting with novel tools and mediums (including the occasional animated gif) to tell stories and demystify the news. Jeremy’s an East Coast transplant who moved to Juneau in 2008.
