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Mass: Summer In Western Wash. Went From Dry To Normal In Just One Week

Aaron Brethorst

A week of rain has turned what was a dry summer into a normal one, says KPLU weather expert Cliff Mass.

But don’t let the clouds and drizzle get you down. Mass says the forecast will progressively warmer and sunnier over the weekend.

Warm And Sunny Days Returning

Saturday will bring morning clouds and a few showers as a ridge of high pressure begins to rebuild. Sunday, says Mass, will be the best day.

“Sunday is the beginning of a real improvement. Temperatures should get up into the low 80s,” Mass said. “So that’s the day over the weekend you want. And then it looks like it will be even warmer on Monday.”

After Lightning-Packed Night, Dry Summer Turns Normal

Mass says we’re now back to a mellow late-summer weather pattern, especially compared to last week, which brought a striking mix of record heat followed by serious rain and lightning that sparked new forest fires, some even in western Washington.

“That shows you how dry things have gotten,” Mass said.

The National Weather Service issued a rare red-flag warning for potential fires on the western slopes of the Cascades.

“I was stunned to see that,” said Mass.

It came true. On Monday, the mercury hit 96 degrees in Seattle, which is 20 degrees hotter than normal. The heat wave broke daily records at weather stations statewide.

“Of course, that dried everything out and that allowed the lightning to work,” Mass said. “And when the trough came in after that, with massive amounts of lightning, there were a lot of additional fires.”

But the trough also brought a lot of rain with it — more than an inch from Tuesday night into Wednesday, helping fire crews get ahead.

“And even some of the eastern Washington fires have been helped by having the rain,” Mass said. “So the rain was enough to make a difference.”

And when you look at the rainfall totals, it also tipped the scales to make the summer a normal one, as opposed to a dry one, for western Washington, says Mass. But he says the way we got there hasn’t been routine, but rather dramatic.

Why Fires Have Raged In Washington And Oregon, But Not California

“This hasn’t been a normal summer in the sense that we had extended dry periods and a few short periods of rain,” he said. "We've seen this more than once over the summer."

And that explains why Washington and Oregon have been seeing more forest fires this summer than California has, despite the big draught there.

"They're very dry in California, but they have not been getting these troughs that we're getting that cause lightning and lightning-caused fires," Mass said.

Eastern Washington is still drier than normal for the whole season, says Mass, and California is “extraordinarily” dry with water managers there hoping the predicted El Niño will tip the scales for them. But Mass says western Washington no longer has to worry about drought.

More Rain Ahead

Looking at the longer-range models, Mass says another trough will move in Wednesday, ushering in another rainy stretch next week. It’s the beginning of the end of the hot summer.

“We’re getting away from that mid-summer dry period,” he said. “So we should see more frequent rain as we go into the rest of the season.”


The weekly KPLU 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 KPLU 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 a podcast of “Weather with Cliff Mass” shows.


Bellamy Pailthorp covers the environment for KNKX with an emphasis on climate justice, human health and food sovereignty. She enjoys reporting about how we will power our future while maintaining healthy cultures and livable cities. Story tips can be sent to