Weather with Cliff Mass

University of Washington Professor of Atmospheric Sciences and renowned Seattle weather prognosticator/personality Cliff Mass has joined KNKX’s roster of commentators.

"Weather with Cliff Mass", our five-minute feature hosted by KNKX's environment reporter Bellamy Pailthorp, airs every Friday  at 9 a.m.  following "BirdNote", and repeats twice on Friday afternoons during All Things Considered. 

Ways to Connect

Elaine Thompson / AP Photo

Showers are in the forecast for Western Washington this weekend. But knkx weather expert Cliff Mass says the relatively minor precipitation expected marks a break in what has been a remarkably rainy October so far.

“I should stress how wet it has been.  The last two weeks have been extraordinary,” he said. “A number of places in the lowlands have gotten five to six inches – some more – and the mountains have gotten hit by five to 10 inches. You know, a lot of rain!”

Mass says this means there is a chance Seattle will break the all-time record for October rain: 8.96 inches.

Courtesy of Tim Durkan

Wet, stormy weather pounded Western Washington Friday morning, with heavy rain and winds gusting from 20- 30 mph in the Puget Sound region, taking out power for several thousand residents, especially along the coast. Oregon was hit even harder.  

Elaine Thompson / AP Photo

Very stormy weather is on its way to Western Washington. Forecasters have issued a high wind warning starting Thursday evening at 6 p.m., through Friday morning at 7. That means there could be gusts of up to 55 miles per hour and there will be several inches of rain, especially in the mountains.

Elaine Thompson / AP Photo

As Hurricane Matthew bore down on the East Coast, the first major storm of the season was hitting Western Washington. They’re not connected meteorologically, but knkx weather commentator Cliff Mass says the weather here was still quite intense on Thursday night and more will be coming in this weekend.

Ted S. Warren / AP photo

Fall got off to a damp and cloudy start in the Pacific Northwest on Friday. But knkx weather expert Cliff Mass says he expects “a nice fall weekend” ahead with plenty of sun, warming temps and an especially sunny flourish on Monday.

Mass says a weak Pacific front was moving in Friday morning “and it’s kind of getting split apart, so we’ll have clouds over most of the region, showers along the coast, in the Cascades and in the South Sound, but only a few sprinkles around Puget Sound because we’ll be somewhat rain shadowed by the Olympics.”

Tim Durkan / Tim Durkan Photography

Enjoy one last day of summer-like weather in the Puget Sound region on Friday, but brace yourselves for a big change on Saturday. Knkx weather expert Cliff Mass says the wettest weekend of the summer is on its way. And it will remain rainy and cool for the foreseeable future.

Tim Durkan / Tim Durkan Photography

School may have started for most kids in the Northwest, but the clear skies and warmth of late summer are still in play. Expect mostly sunny and dry conditions for most of this weekend, says knkx weather expert Cliff Mass.

And then it gets even better as we enter next week.

“The weekend will have a little bit of clouds, but next weekend should be really very nice,” Mass said.

Clear Skies Friday Afternoon

On Friday, he says temperatures will get up into the lower- to mid-70s, with some clouds in the morning, but those will mainly burn off. 

Elaine Thompson / AP Photo

A line of convection brought rain into greater Seattle Friday morning, but knkx weather expert Cliff Mass says that should be the worst of it over the long holiday weekend for most places around Puget Sound.

“We’ll see just showers most of the day, except in northern Puget Sound,” Mass said, noting that he expects a Puget Sound convergence zone to form late in the day, bringing some heavier showers from North Seattle up to Everett.

Tim Durkan / Tim Durkan Photography

If you like the sunshine and heat, get out there and enjoy it on Friday. A heat advisory is in effect through the evening, with highs expected in the mid-80s to low 90s. But KPLU weather expert Cliff Mass says a cool down is coming, likely marking the start of a big transition to cooler conditions as summer in the Northwest begins to wane.

Elaine Thompson / AP Photo

An excessive heat warning has been in effect since Thursday this of week and temperatures are expected to hit the 90s  in places around the Puget Sound region through Saturday.

It will be sunny and hot all weekend long. And the heat wave comes as no real surprise; This is typical weather around here for August, when we expect our hottest temperatures of the year.

But why now?  Shouldn’t it be in June, when the sun is strongest?

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It’s hard not to gloat about Northwest weather in a week like this one. And KPLU weather expert Cliff Mass says the glory of blue skies and warm but comfortable temperatures is set to continue for most of the coming weekend.

“We’re stuck in this pattern of near perfection of weather,” Mass joked. “We’re in the 70s and low 80s and dry conditions while the rest of the country’s in heat and humidity and thunderstorms. So we can’t complain,” he said.

Warmest On Friday

Elaine Thompson / AP Photo

The first weekend in August is statistically one of the driest and warmest weekends in the Pacific Northwest. It also marks the height of outdoor summer fun in Seattle as Seafair’s hydroplane races hit the water and the Blue Angels show off their daredevil moves in the skies above.  

KPLU weather expert Cliff Mass says this year’s Seafair Weekend forecast is for cooler than normal weather and even some rain.

“But the rain’s going to hold off till the end of Sunday, so I think most activities will be fine,” Mass said.

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Have you ever noticed that oftentimes on summer afternoons, big clouds seem to form right over the Cascades or the Olympics, almost like the mountains have their own weather systems? They do.

“It’s true,” says KPLU weather expert Cliff Mass.

“Many summer afternoons, we see puffy cumulus clouds starting to form over the upper slopes of the Cascades. And they increase in width and height during the afternoon and quite frequently you have a few showers there – even some lightning,” he said.  “And so that’s real, we see it over the Cascades, we see it over the Olympics.”

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“Liquid sunshine” made an ample appearance as the Northwest weekend got off to a wet and cloudy start. But KPLU weather expert Cliff Mass promises warmer temps and clearer skies as the weekend progresses. In fact, he says we’re headed into what is usually one of the nicest times of year and he expects it won’t disappoint.

“We’re about to go into an extended dry spell,” Mass said.

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Mid-July is well into what most people in the Pacific Northwest consider the summer season, which can be delightfully sunny and warm. Last year, it was characterized by record heat.

Not this year. KPLU Weather expert Cliff Mass says it will be pretty gray for most of this weekend. And though it feels cool compared to last year, it’s actually relatively average in terms of temperatures.  

Joey Cohn / KPLU

Expect the cool, cloudy skies and rain to continue this weekend. KPLU weather expert Cliff Mass says the unseasonable weather is so extreme this year, he’s coined a new phrase for it: “Januly.”

He says though it’s not quite as cold as January, the patterns he’s seeing in the atmosphere resemble ones more typically seen in winter.

This Independence Day, don’t expect the scorching heat we’ve seen in recent summers around here. But it will be pleasant this year, with fine conditions for viewing fireworks, says KPLU weather expert Cliff Mass.  

“You know this is going to be a classic July 4th weekend,” Mass said, “where there’s a lot of clouds and a few sprinkles.”

Tim Durkan

It’s been cool, damp and showery in the Northwest lately, with a classic pattern of June gloom overshadowing the official start of summer earlier this week. But that’s about to change. KPLU weather expert Cliff Mass says the heaviest rains are over for a while.

He says the recent clouds and precipitation were caused by an upper-level disturbance moving through the region. Mass says that will pass through the area by Saturday morning.

Tim Durkan

Prepare to get wet on Saturday. But don’t lose hope. The sun will be back on Sunday, just in time for Father’s Day festivities as Northwest skies serve up a spring mix of rain and shine this weekend.

KPLU weather expert Cliff Mass says Friday’s conditions should set the tone. You’ll want to keep sunglasses as well as a rain slicker handy.

"It’s sunny from Seattle northward," Mass said. But he says conditions will start to change come Friday afternoon.

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Late spring in the Northwest is known for cool and showery weather, what’s often referred to locally as “June gloom.” After a record breaking heat wave last week, it looks like the normal pattern has returned to Western Washington skies – and that it will stick around for quite a while.

“June is traditionally a time of clouds and showers,” said KPLU weather expert Cliff Mass, adding “this weekend won’t disappoint.”

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The official start of summer has not yet arrived, but folks in the Pacific Northwest will feel like it has this weekend.  KPLU weather expert Cliff Mass says the mercury will rise into the 90s in many parts of Washington, bringing unseasonably hot weather to the region.

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Light snow fell at Steven’s Pass Thursday night, serving as a reminder that spring’s not quite over yet, said KPLU weather expert Cliff Mass.

But he says that’s about as surprising as it will likely get this weekend. He’s expecting the gloomy Northwest weather that’s been persisting this week to continue through the weekend.

“Today and tomorrow and I’m afraid Sunday are going to be pretty cloudy west of the Cascade Crest,” Mass said. That’s because of some very strong onshore flow that’s currently driving the weather.

A Persistent Trough

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If you were tired of all the unseasonably warm and sunny weather Washingtonians saw up till last week, it looks like your prayers have been answered, says KPLU weather expert Cliff Mass.

“For those people who were complaining about the heat and the warmth and the sun and the dryness, well, your prayers have been met,” Mass joked.  He says we are now in a relatively wet, cool pattern that he expects to stick around well into next week.

A Major Trough

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Enjoy Friday’s summer-like weather while you can. With a predicted high of 80 degrees or more, it will be the last day of unseasonably warm weather for at least a week and likely much longer, says KPLU meteorologist Cliff Mass.

He says the recent string of high temps is ending with a bang.

“It’s amazing; The temperatures will get up to 80, maybe even lower 80s in a few locations, and completely dry,” said Mass, a professor of atmospheric sciences at the University of Washington.

Sea Turtle / Flickr via Compfight

Keep the sunglasses and shorts handy.  More bright blue skies, sunshine and temperatures in the mid to high 70s are in store this weekend and beyond, with the exception of on Mother’s Day.

“Lots of sun, just a few clouds, but nothing much — perfect,” said KPLU weather expert Cliff Mass.

After A 'Normal' Week, Things Will Heat Up Again

Apr 29, 2016

"The atmosphere has been very kind to us," KPLU weather expert Cliff Mass said. "The weekend is going to get progressively sunnier and warmer as we go on."

Friday will be cloudy with some modest rain, but as we get later in the day the front will move out and the rain will come to an end. We'll see 60s and 70s over the weekend for our highs and Mass says by Monday we could see temperatures into the 80s. But it won't be as warm as our record-breaking heat from earlier this month. Mass says it's been a "normal" week. 


Gray skies and drizzle marked a return to normalcy in Northwest skies on Friday, with temperatures back in the 60s after an extraordinarily hot week that broke multiple records and caused a rapid meltdown of snow in the mountains.

KPLU weather expert Cliff Mass says the weekend will bring more of the same, with mild temps and potential for lots of late April showers.

Rainy Start To The Weekend

Tim Durkan Photography

Expect a fairly normal spring day on Friday, but keep your summer gear handy for the weekend. KPLU weather expert Cliff Mass says temperatures will surge upward on Saturday.

”We’re going to a profound warming trend,” Mass said, “And no precipitation.”

Blue Skies Start Saturday Afternoon

He says it’s due to a ridge of high pressure that will start building over us on Saturday.

“And the temperatures are going to push up into at least the mid-60s, maybe some clouds in the morning, but lots of sun, so definitely a warm-up,” Mass said.

Tim Durkan Photography

Western Washington’s unseasonably high temperatures will be subsiding, but KPLU weather expert Cliff Mass says you may want to keep the shorts and sunglasses handy.

“I’d keep them around,” Mass said, though he added that many people will be needing them less over the weekend. He said Friday will still be very warm and sunny.

Another Hot Day Friday – Except On The Coast

“Maybe not quite as warm as yesterday, in some places,” he said, but the air above us is still “warmer than we generally see till the middle of summer.”

Recent Windstorm A Powerful One, But No Hurricane

Mar 25, 2016
Ted S. Warren / AP Photo

The windstorm that hit the region March 13 was a powerful one, to be sure. We were seeing wind gusts as fast as 70 miles per hour in some spots along the coast, with gusts up to 40 miles per hour inland. The National Weather Service was quoted recently comparing it with a hurricane, but KPLU weather expert Cliff Mass says "not so fast."