If you were hoping April showers would hold off this weekend, don’t hold your breath. Be ready for more of the cool, wet weather that has been persisting in the Pacific Northwest in recent weeks.
“There may be a break for a few hours, so you could look forward to that,” joked KNKX weather expert Cliff Mass.
Mass, a Professor of Atmospheric Sciences at the University of Washington who hosts a popular weather blog, says he’s been getting a lot of messages from people complaining that the weather this spring has felt colder and wetter than normal. He says it depends where you are, but generally speaking, those folks are right.
La Niña’s Influence
“Here in Seattle, we’ve been a little bit cooler than normal,” Mass said.
Case in point: Thursday. It was much cooler than normal – 7 degrees below normal. “It should be 58 and we only got to 51,” he said.
Mass says that’s more extreme than it has been overall. Seattle has been a just few degrees cooler than normal this spring so far. And it’s had a few inches more rainfall than normal for the year so far.
In eastern Washington, he notes it’s been far wetter than normal.
“A number of places have gotten 30-40 percent more rain than they normally do,” Mass said.
“So we have been wetter. We have been cooler. And we can trace this back to the La Niña situation that we’ve talked about many times in the past.”
During La Niña years like the one still persisting, the Pacific Northwest tends to see a trough of low pressure over the coast, which can cause wetter, cooler weather. Mass says he doesn’t see that easing up anytime soon.
Wet and Cold This Weekend
The forecast for this weekend? More rain.
“A warm front is moving through and behind it a weak atmospheric river – moisture from the sub-tropics” Mass said.
That means expect it to be raining most of the day Friday, with winds from the south. Expect a wet and breezy day, with temperatures below normal.
“At SeaTac, we should get to 58 degrees on an average day today, but no – it’s going to get only to 50-52-53, something like that,” Mass said. “Definitely cooler than normal.”
He says that front will dominate all weekend, bringing more of the cool, wet weather in, with temperatures in the lower 50s continuing.
“On Sunday, I think the front’s slowly going to slide south of us, but I think there’ll be a lot of showers, at least through about three o’clock on Sunday,” Mass said.
He says it will lighten up a bit later in the day, but not much.
“The damage will be done,” Mass said.
No End In Sight
Looking ahead to next week, Mass doesn’t expect any letup anytime soon.
“I hate to say it, but next week looks like a continuation of this,” Mass said. “I’m looking at the long-range forecasts and they have a trough of low pressure digging all the way down to California. So, we can expect rain on and off for at least the next week.”
Mass says the bright side is that all the precipitation will add to reservoirs and snowpack, which are already shaping up pretty well.
“With this low pressure and cooler air, snow will come back to the Cascades and to the mountains even in California,” Mass said.
“So the snowpack’s going to continually increase – at least through the next week.”
To hear the full conversation, including discussion of how this year’s La Niña is weakening and what that means for this summer's weather, 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.