Clear blue skies and sunshine got the weekend off to a beautiful start in Western Washington. Both are expected to stick around all day Friday, before shifting to showers Saturday morning.
“Today’s going to be a really nice day,” said KNKX weather expert Cliff Mass. “It’s going to be perfect – no rain.”
He said that will change tomorrow, when an upper-level trough of lower pressure comes in. “So, Saturday morning, we’ll see quite a bit of clouds, there’ll be a few showers — particularly Saturday morning into early afternoon, nothing serious,” Mass said.
But that trough will bring cooler temperatures, knocking them back into the upper 50s.
And, he says, it will be cloudier and the showers more intense in the mountains, especially on the western side of the Cascades. “If you’re planning that hike on Saturday, I’d take a little bit of rain gear with me,” he said.
Sunday should be better, as the trough moves through but still hangs around a bit. “There could be a few sprinkles, but not much — I expect a lot of sun on Sunday, temperatures rebounding into the lower 60s,” Mass said.
Next week, there will be a few weak disturbances that could bring clouds. “But nothing serious, temperatures generally getting up into the lower-mid-60s and there will be plenty of sun,” He said. “So, a relatively dry period — and the worst conditions on the western side of the Cascades.”
AIR QUALITY QUESTIONS
Mass says many people have been asking him about air quality this week as wildfire season looms. A new report from the American Lung Association says the Seattle-Tacoma area is ninth-worst in the nation for short-term particle pollution. Yakima and Spokane are also in the top 15.
Mass blogged this week about the state’s air quality and concluded that it has actually improved over the past 15 years — except during summer periods of wildfire smoke.
“On average, we’ve gotten much better. And that’s because we have cars and trucks that are much more efficient, they’re putting out much less particulates," Mass said. "The ships are putting out less pollution, people are using wood-burning stoves less. So, in the wintertime, air quality is much better."
The big change — especially over the past two years, Mass says — is the big spikes of smoke from wildfires coming into Seattle.
“And then we were unlucky,” Mass said. “The last two summers, we had a relatively major wildfire just to the east or northeast of us. And the winds happened to push it in, just in the right way.”
It all came together to create conditions few people here had ever seen before. “During the last two summers, here in Seattle, we’ve had periods that the air was worse than Beijing,” Mass said.
LOTS OF SMOKE THIS SUMMER?
At this point, Mass says, there is no reason to expect another major spike of wildfire smoke, though it could happen.
“Right now, the snowpack is just a little bit below normal. We haven’t been totally dry. The temperatures have been relatively normal,” Mass said. “So, going into summer, there’s no reason to expect anything different than normal.”
Mass says, of course, there is always a chance of a fire that sets up perfectly and winds that push smoke toward people, causing another serious air quality problem, but conditions are not prime right now.
SMOKEY SUMMERS THE NEW NORMAL?
Mass says people often ask him about the overall trend — should we generally expect periods of serious smoke pollution in summer, since it’s become more common?
He says the answer depends on what we do about our forests, especially in Eastern Washington. “The eastside forests are really problematic," he said. "We’ve suppressed fire now 50-100 years. A lot of the forests are very explosive.”
They’ve grown thicker than they would be naturally — and often increasingly dry. The infernos that result when they catch fire are not natural.
“If we go back 100-120 years, we used to have a lot of small fires, now there’s a greater tendency to have these big fires,” Mass said.
And these major blazes are usually the ones that result in smoke traveling all the way over the mountains, when weather and wind conditions set up right.
“So, the key thing is to take care of our forests,” Mass said.
MANAGE FORESTS, REDUCE RISKS
The state Department of Natural Resources has made a big funding request this year, partly to tackle this issue. Early drafts of budgets from the House and Senate seemed sympathetic to that ask. The final budget is expected to be approved this weekend, as the session wraps up in Olympia.
And in the longer term — decades or longer from now — Mass says the climate will change, as carbon dioxide increases.
“So we expect warming conditions, which would probably promote fire in the long term,” he said. “But the key thing now is to deal with the forests.”
To hear the full conversation, 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.