"Today is the calm before the storm," says KPLU weather expert Cliff Mass.
The first big storm of the season will hit the Northwest on Saturday, and it's expected to produce winds strong enough to cause power outages and trigger snowfall in the mountains at elevations low enough to cover the passes.
First, the Calm
Friday's outlook is mild, with temperatures into the mid-50s, a few clouds, and no rain to speak of.
“So a really decent day, but things change tomorrow," said Mass, who teaches atmospheric sciences at the University of Washington.
Mass says we should brace ourselves for a windy Saturday with heavy precipitation, including quite a bit of snow in the mountains.
Then the Storm
Driving the storm is a low center that's approaching Vancouver Island, which will allow increasingly-strong winds up to 60 mph starting late Friday or early Saturday morning. Mass says they’ll hit first on the coast, especially in the area from Whidbey Island up to the San Juans, then move into the Northwest interior. It will become increasingly intense as the system moves through.
“Westerly winds are going to punch through the strait, and we’re talking about the potential for wind gusts to 50-60 miles per hour,” he said.
Mass said the eastern Strait of Juan de Fuca and northern Whidbey Island are particularly vulnerable.
“So I would not be surprised if there were a few power outages with that,” Mass said, and strong winds up to 50 mph will whip up the coast.
In the lowlands away from the coast, expect heavy rain that will taper off Sunday.
In the mountains, computer models show Snoqualmie and Stevens passes could get 6 to 8 inches of snow and up to a foot and a half at higher elevations.
“So, this will be the first significant snowfall in the Cascades so far this season, Mass said, “sort of the end of hiking season and the beginning of thinking about skiing.”
Next week will be cooler, with temperatures in the 40s and 50s and clouds and showers starting Sunday.
Note: Cliff will host a talk next Thursday about the storm that destroyed Ivar's at Mukilteo Landing a decade ago. He's eager to meet KPLU listeners.
The weekly KPLU feature "Weather with Cliff Mass" airs every Friday at 9 a.m. immediately following BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KPLU Environment Reporter Bellamy Pailthorp. Cliff Mass is a University of Washington Professor of Atmospheric Sciences, a renowned Seattle weather prognosticator, and a popular weather blogger. You can also subscribe to a podcast of “Weather with Cliff Mass” shows.