‘Atmospheric river’ could bring 10 inches of rain to Juneau

A truck drives by an active mudslide in Juneau, Alaska.
A truck drives through an open lane after a mudslide on Monday, December 11, 2017, in Juneau, Alaska. The slide happened near the intersection of Mill Street and Thane Road south of downtown Juneau. (Rashah McChesney/Alaska’s Energy Desk)

As much as 10 inches of rain could cause flooding and mudslides in the Juneau area this week.

The National Weather Service issued a flood watch for Juneau that started Monday evening and runs through Wednesday night.

Meteorologist Caleb Cravens said an atmospheric river, or low pressure system, will pick up warm moisture from the southern Gulf of Alaska and dump it on the eastern gulf and the Southeast Alaska Panhandle.

Along with the heavy rainfall, wind gusts are expected to top 45 miles per hour in Juneau.

“When you have winds like these and heavy rains, it increases the potential for trees falling down as the winds are blowing hard on those and you have saturated soils,” Cravens said.

Mudslides are usually caused by saturated soils. Capital City Fire/Rescue is asking people who live or recreate on hillsides to be ready for extreme weather and have a plan for evacuation on short notice.

Instead of passing through quickly, Cravens said the storm system will be “sticking around for a while.” Heavy rainfall is expected to last into Thursday.

The snow level will eventually rise to 5,000 feet, melting a lot of the snow at higher elevations like at Eaglecrest Ski Area. That will add to water levels in creeks, streams and rivers.

The City and Borough of Juneau’s Docks and Harbors Department encouraged boat owners to check their boats, confirm their mooring lines are secure and their pumps are operating correctly, and make sure all that rainfall is not collecting in their vessel over the next several days.