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'Wicked Rain,' Snow In The Mountains And A Soggy Weekend in Western Wash. Lowlands

Elaine Thompson
AP Images
Max Kleweno, 9, of Lake Forest Park, Wash., tries to deflect a snowball thrown at him as he plays in the snow, Wednesday, March 31, 2010, at Stevens Pass, Wash.

Heavy rain is back and many people in the Pacific Northwest are starting to get tired of it.

KPLU weather expert Cliff Mass confirms that ‘wicked’ is a fine word to describe it, especially on Friday.

“We have an occluded front coming through. And I can see on the radar some fairly heavy rain on the coast coming into the Puget Sound region, so it will be wickedly raining,” he says.

That front, which is the kind in which high and low pressures are engaged in a bit of a wrestling match,  will move through later in the day, says Mass.

“And so I think we may see the rain back off later in the afternoon, but then we get into westerly flow that will be cold and instable and we can expect showers in the lowlands” he says.

So on Saturday, it will be wet in the lower elevations, with temperatures dropping to the upper or mid-30s. Up high, it will be freezing with loads of snow coming through.

“Substantial snow in the mountains -- there could be a foot of snow in the passes,” Mass says.  

In fact, there’s a winter weather advisory in effect for the passes.

“On Sunday, we’ll still have a few showers, but it’ll be a better day, be partly cloudy,” Mass says, “with a few sprinkles here in the lowlands, continued snow showers in the mountains, but backing off. “

And then it looks like Monday will be a relatively dry day, as high pressure builds in.

Big Atmospheric River Bringing Weather In

“We’ve had lots of atmospheric river action this week,” Mass says, as a plume of moisture from the sub-tropics delivered a series of heavy precipitation events.

“Those are associated with atmospheric rivers – relatively narrow currents of warmth and moisture that come out of the sub-tropics,” Mass explains.  

“So, we had our turn earlier this week and [in] the mountains, some locations got 5 or 6 inches.”

Now, the atmospheric river has moved southward into California, Mass says.

“They are getting hammered. Northern California is getting 1-4 inches, particularly in the mountains, which will be extraordinarily useful for their water situation,” he observes.

Mass says as the atmospheric river goes Southward, the Pacific Northwest gets into cooler air.  

“And that’s why we’re transitioning to snow right now.”


For a Weather 101 discussion of why some storms are relatively easy to predict (Winter Storm Jonah this past week) and why others are more challenging (Hurricane Sandy in October 2012,) listen to the entire segment – you can download and podcast it, or listen online by clicking on the “play” icon at the top of this story.


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.

Bellamy Pailthorp covers the environment for KNKX with an emphasis on climate justice, human health and food sovereignty. She enjoys reporting about how we will power our future while maintaining healthy cultures and livable cities. Story tips can be sent to