Heavy rain and mountain snow have returned to the Northwest, but this weekend will be dry | KNKX

Heavy rain and mountain snow have returned to the Northwest, but this weekend will be dry

Nov 23, 2018

After a string of dry and sunny weekends in greater Puget Sound that had some of us here a bit concerned about the water supply, KNKX weather expert Cliff Mass says don’t worry. He says the normal late November pattern of heavy precipitation has set in and will extend into next week and beyond. It even dusted the mountains with some Thanksgiving snow.

“It shouldn’t be Black Friday, it should be White Friday in the mountains, because they’ve gotten substantial snow,” Mass said. And that comes just in time for opening day at Crystal Mountain ski area, Mass said.

Cold And Showery Friday

The heavy precipitation has come thanks to a series of weather systems moving through the region over the past few days.

“The last is moving through this morning,” he said early Friday. “Some places in the mountains have gotten 1-2 inches of liquid precipitation. And above roughly three or four thousand feet, half a foot to a foot (of snow) can be expected.”

He says on Friday, the last remnants of an upper level short wave that brought all kinds of thunderstorms and showers with it was moving through.

“And that’s going to be moving through… into the afternoon.”

That means expect showers on and off on Friday, with high temperatures only reaching the upper 40s.  

“You know, cool day, showers,” Mass said.

But Dry This Weekend

Mass says expect that pattern to continue, pretty much indefinitely. But there will be breaks.

“The interesting thing is this weekend is actually going to be pretty decent,“ he said. “We’re going to have a break, in which temperatures will be upper 40s and virtually no precipitation over the region on Saturday and Sunday.”

Mass explains, the dry weekend here is connected to a big wet spell south of us, in California.

“The jet stream went south of us. And that is bringing one system after another into California. And they’ve been getting much heavier precipitation in Northern California. Some places in the mountains there have gotten three to four inches of rain,” he said. “It’s really wet.”

He says rain will return to western Washington on Monday and Tuesday. And it will stick around

“There’ll be showers on and off for the next week or two,” he said. “So we’re in the pattern now.”

Mass says that pattern will likely fill up our reservoirs and build snowpack, so there’s no reason to worry about the water supply at this point in the season.

“One should never worry about the water supply here before you get to December,” Mass said. “I can think of a dozen situations where the first half of November was relatively dry. But it is extraordinarily hard for us not to start raining the third or fourth week of November.”

He says those are typically the wettest period of the year. True to form, it looks like the jet stream that powers most of our winter rain is coming back again; and with a weak El Niño still in the cards, it should be a pretty wet season. So, get out the rain gear and be ready.

To hear the full conversation, including Cliff’s take on how the effects of the jet stream that powers our winter rains differ for Washington and California, you can click on the "play" icon at the top of this post.

Weather with Cliff Mass airs at 9:02 a.m. Friday, right after BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KNKX 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 podcasts of Weather with Cliff Mass shows, via iTunes or Google Play.