The sun broke through on Thursday this week, providing a much-needed respite from a string of wet days that has many Northwesterners longing for blue skies. KNKX weather expert Cliff Mass says he’s ready for more sun too. But he says this weekend will be a mixed bag.
“About 50-50,” Mass said is the ratio of rain to sun he expects in the days ahead. He says another frontal system was moving into the region Friday morning and a mini-atmospheric river aimed right at us.
“So as we get into the day, the rain’s going to pick up again and the values will be pretty substantial,” he said, “In the mountains, several inches – half an inch to maybe a few tenths here in the lowlands; so another wet day.”
Temperatures will reach into the mid-40s, maybe 47.
Rain Increasing Saturday
Saturday, a transition begins. After the front moves through, a Puget Sound ‘convergence zone’ will develop. That’s when air masses that have been split apart by the Olympic Mountains come together over Puget Sound and drop a band of precipitation somewhere north of Seattle.
It’s a phenomenon that is more frequent in springtime, when the prevailing winds create the right conditions for it.
“So expect some rain somewhere between Seattle and Everett. And there’ll be showers in the mountains as well,” Mass said.
He says the freezing level will go way up, causing rain in the passes and very little new snow in the mountains. Temperatures in the lowlands will again hover around 47 degrees.
Sunnier Sunday and Monday
“The best day of the weekend will definitely be Sunday,” Mass said. “A mini-ridge [of high pressure] will develop over us, and we’ll have dry conditions, even some sun, with temperatures getting up to about 50 – can you imagine that?”
Then it gets even better on Monday, Mass says, with temperatures likely climbing into the mid-50s.
“And no rain on Monday. There could be some high clouds coming in,” he said. “But Monday is going to be very different. We haven’t been in the mid-50s with dry conditions for a while.”
Better enjoy that while it lasts though, because Mass says as the week progresses, the ridge will move back and the showers and rainy weather will return.
To hear the forecast along with Cliff’s discussion of the very wet ‘water year’ we’ve had this winter, you can click on the “play” icon at the top of this post.
The weekly KNKX 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 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.