Mass: Get Ready For Temps In The 80s Before ‘June Gloom’ Sets In

May 19, 2017

Get ready for temps in the 80s next week. That’s what KNKX weather expert Cliff Mass says people in the Pacific Northwest can look forward to on Tuesday.

First, we have to get though more of the lovely cloudy weather that has been decorating the views in Cascadia.

“A weak ridge has developed over us; we do have some onshore flow” said Mass of the current pattern.

Onshore flow is when the winds blow in from the ocean, bringing sea breeze along with those lovely views.

Friday, Mass says expect a partly-cloudy day with temperatures getting up into the mid to upper 60s.

“So, a pretty decent day.  It should be dry,” he said.

But then an upper-level trough of pressure will be coming through on Friday night and on Saturday morning.

“So that’s going to thicken things up a little bit – a little more marine air will come in,” Mass said, adding that there could be a few sprinkles on Saturday morning as well.

“But as we get into later Saturday, a ridge of high pressure will start building in,” Mass said.

That ridge will push the clouds away later in the day, especially in the northern Puget Sound area and northward, towards Bellingham, with temps touching the 60s.

“Then then the magic starts,” Mass said. “A ridge of high pressure builds over Sunday, Monday, Tuesday, Wednesday.”

Mass says that is the dynamic that will make the temps hit first the 70s on Sunday. Then they will soar all the way up to 80 by Wednesday, he predicts.

“Certainly mid-70s on Monday — maybe upper 70s.  And then on Tuesday — I can barely believe I am saying this —the temperatures will probably get above 80 degrees on Tuesday, so it’s going to be unbelievable," said Mass.

With all the gloomy weather lately, people here may be asking whether this is normal, and the answer is yes. Mass says it’s not outside the norm.

“It’s not unusual," he said. "In fact, we typically get a period of warmer temperatures, offshore flow and sort of a surge of sun sometime in mid-May.

“I laugh about it.  Sometimes it starts the second week, sometimes the third, but we generally get this pulse of warmth for a few days in mid-May, before we start settling down to something I hate to think about, and that’s the June gloom,” said Mass.

“June gloom” refers to the typical pattern of fogginess that builds because of the pressure system.  

"Because this high pressure builds in the eastern Pacific, the low clouds spread out over most of the eastern Pacific ocean and that gets pushed into us,” he said.

Mass says enjoy it while it lasts. The sunny, warm spring highs of May are here.

To hear the full discussion of the weekend weather along with an explanation of what might have propelled the race times of crew teams going through Seattle's Montlake Cut earlier this month, 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.