Winter snowstorms pummelled the US Northwest again today as a larger weather system wreaked havoc in the region and even brought snow to Hawaii.
A chunk of cold, low-pressure air separated from the main flow is drifting west. Known as a Kona Low, the system caused unusual snow on the island of Maui.
Hawaii officials said the blanket of snow at Polipoli Spring State Recreation Area is likely the first for any state park. Polipoli is at 1900 metres and is possibly the lowest elevation snow ever recorded in the state.
When Lance Endo's friend camping at a state park on Maui texted him yesterday that there was snow he jumped in his truck and drove more than hour to see it.
"I just wanted to go play in the snow," Endo said.
Meanwhile in Northern California, Humboldt County beaches that have not had snow in more than 15 years received a dusting and blizzard conditions caused whiteouts on mountain roads.
And in Washington state, Seattle's metro area had already been hit by three snow storms this month and the National Weather Service reports that Seattle-Tacoma International Airport has received 36 centimetres of snow so far in February, more than twice the annual average and the snowiest month in more than 30 years.
The storm that hit Seattle on Monday dumped up to 15 centimetres of snow and forecasters said more snow or rain was expected today and tomorrow as a lingering jet stream drives cold arctic air into the normally temperate region, and part of a larger cycle that has also driven snow as far away as Hawaii.
In the state capital of Olympia, lawmakers cancelled meetings and the University of Washington in Seattle and Washington State University in Pullman called off classes.
In Seattle, the snow's effects were amplified by a prolonged stretch of cold temperatures.
"You've got storm after storm sliding down the sweet spot to produce low-level snow," said Kirby Cook, a meteorologist at Seattle's National Oceanic and Atmospheric Administration office. He described weather systems pulling cold air from Canada and combining it with moist air pulled east from the Pacific Ocean.
When snow does fall in the area, normally enough warm air is drawn from over the Pacific to melt it soon after it falls, but the steady stream of cold air has kept normally-mild western Washington colder than normal — and let the snow build up.
"It's really rare for us to maintain this pattern," Cook said.
Joe Zagrodnik, an atmospheric scientist at the University of Washington, said the larger system at work — namely the position of a cold jet stream — was also driving warm temperatures in Alaska and unusual weather in Hawaii.
With a north-south ridge of high pressure situated off the coast of Washington and Canada, Zagrodnik said, cold air being drawn southward inland is being replaced by warm air moving north offshore, driving temperatures up in parts of Alaska even as Seattle freezes.