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Weather With Cliff Mass

KNKX Public Radio

yes yes yes 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.


Tacoma, WA


yes yes yes 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.






12180 Park Ave S. Tacoma, WA 98447 253-535-7758


School of Jazz: Ian McKain-Pitts and Aidan Moore serve as guest DJs

Drummer Ian McKain-Pitts and saxophonist Aidan Moore from Bellarmine Preparatory School in Tacoma will virtually join Abe Beeson on Evening Jazz tonight at 8 p.m. (Oct. 1) as guest DJs. Listen to the show and read their Q&A.


How extreme heat in Eastern Washington can cause cooler temperatures in the west

The first week of August is generally the hottest time of the year in Washington. This year, people in the Puget Sound region already have experienced some record temperatures, with highs topping 90 degrees for the first time in 2020 on Monday. Olympia reached an eye-popping 98 degrees. Seattle made it to 94. But a cooling trend that will continue through Monday has started, says KNKX weather expert Cliff Mass.


Is that a ferry boat in the sky? How summer mirages play tricks on your eyes

This story originally aired Aug. 23, 2019. Most people have had that classic summer experience of driving along a warm road and seeing a shimmering patch ahead that looks like water. But when you get there, it’s gone. This is a trick of the atmosphere, caused by different densities of the air, associated with temperature.


Clear skies and warm temps offer perfect viewing of Comet NEOWISE

It’s that most wonderful time of the year in the Pacific Northwest, when we get to enjoy clear skies, warm yet comfortable temperatures and 9 p.m. sunsets. Summers here are the payoff for our long, dark winters. And this week, the "perfect weather" many of us like to gloat about has finally arrived. This summer, these conditions are coinciding with the appearance of a rare comet called NEOWISE. KNKX weather expert Cliff Mass is among the astronomy enthusiasts who ventured out at 3 a.m. to...


'Big experiment' this July 4th shows personal fireworks are the main cause of air pollution

People in the Pacific Northwest sometimes jokingly call the sixth month here "Juneuary," because of the persistently gloomy weather we often face in June. Now an abundance of offshore flow — marine air coming in off the cool Pacific Ocean — has KNKX weather expert Cliff Mass calling July "Julember."


Lack of high-flying community fireworks may spare region’s air quality on July 4

July 4 is upon us. Normally, that means our air quality takes a big hit. It's an issue that KNKX weather expert Cliff Mass often talks about. Mass has studied the impact of fireworks on our air quality. This year, things will be a little different. With all the major community fireworks displays canceled due to the COVID-19 pandemic.


British Columbia’s wet, cold spring bodes well for Washington this year

The curse of the wet weekend is making another appearance as June comes to an end. The month sometimes referred to as "Juneuary" in the Pacific Northwest has actually included quite a few lovely summer days this year, with temperatures hitting the 80s under bluebird skies. (Just not many on weekends.) But our somewhat soggy spring this year in Washington has nothing on what folks north of us in British Columbia have been experiencing.


‘Curse of the wet weekends’ has had a strong hold on our region. What's behind it?

If you feel like you’re being punished by the weather for staying indoors during the workweek, you’re not alone. Lots of people in Western Washington have noticed a pattern of fair and sunny weather that abruptly turns to rain as soon as the weekend arrives.


Forecasting skill fades after two weeks. So how can scientists predict future climate?

We’re in for another cool, wet weekend. Rain and rain showers dominate the forecast through Monday night. High temperatures won’t get past the mid-60s. This is the kind of forecast most of us have come to rely on as we plan our activities, using radar viewers and other online tools to know what’s coming our way, sometimes down to the hour.


A gloomy start to June — but mellow compared to last weekend’s powerful thunderstorms

Gray skies, rain showers and possible thunderstorms are in the forecast again. It’s a pretty typical for this time of year in the Pacific Northwest, where most people rattle off phrases such as "June Gloom" and "June-uary" to describe this kind of weather. The exception here is thunder and lightning. Intense storms that are common in other parts of the country are rare here.


‘The Blob’ is back, warming temps and threatening marine ecosystems, but will it last?

After a string of warm and sunny days, residents of Western Washington were bracing for the effects of an upper level disturbance coming up from California. The weekend forecast calls for significant rain and possible thunderstorms, with temperatures dropping into the mid-60s.


Why the eruption of Mount St. Helens dramatically altered temperatures, but not for long

“An improving trend” is in store this Memorial Day weekend. The clouds, rain and cool temperatures we’ve been experiencing over the past several days will yield to something a little less cloudy. You can expect dry conditions in most places and it will warm up considerably, to as high as 70 degrees on Monday, says KNKX Weather expert Cliff Mass. But it will still be pretty cloudy.


Spring rain is back. That bodes well for local water supplies, wildfire outlook

After a heat wave that left many of us dreaming of summer, more typical spring weather is back in the greater Puget Sound region. That means a chance of rain pretty much every day and temperatures in the 60s, along with clouds and sun breaks. It also means the summer outlook for water supplies, stream flows and wildfires are looking normal to favorable, despite a scary dry spell in April.


Another May heat wave: why low 80s this weekend will not break records

Temperatures around the Puget Sound region were shooting up Friday into the mid-to-upper 70s, after an already warm week. And the forecast for Mother’s Day weekend promises temperatures in the low 80s. It almost feels like summer. But KNKX weather expert Cliff Mass says this kind of heat wave in mid- to late May is not that unusual for the region.


Chance of showers, chance of sunbreaks — so what do probability forecasts really mean?

As May begins, the weather continues to offer that typical grab bag of conditions that is typical for spring in the Northwest: plenty of clouds, along with showers, sunbreaks, even possible thunderstorms. And often, forecasts predict the probability of these phenomena: a 10 percent chance of rain, say — or 50 percent chance. That sounds plausible, but it turns out most people don’t know what that actually means.


The sun's rays are as strong now as they are in August. So why are temperatures so cool?

After a pretty long dry spell, April showers have returned to the Puget Sound region. We’ve entered a typical phase of showers and sun breaks, with lots of instability in the atmosphere that produces dramatic clouds with light blazing through them.


‘Dry storm’ causing static, parched soils and heightened allergies

Maybe you felt a spark as you walked over carpeting and touched a doorknob. Or perhaps you noted how arid the soil was when you went out to do some gardening. These are signs of low relative humidity in the air. And Western Washington has experienced extreme levels of it — on several days this past month. KNKX weather expert Cliff Mass says it’s been so dry, he coined a new term for it: "dry storm."


Thank the ‘omega’ pattern for locking in another week of clear blue skies and sunshine

It’s been warm and sunny lately with clear blue skies and great visibility in the Pacific Northwest — ideal for seeing for events like the supermoon Tuesday night. Contrast that with Southern California, where a pattern of rain and snow in the mountains has locked in, providing much-needed water for reservoirs, but dampening spirits for some who live there. This contrast is due to a configuration in the atmosphere called a blocking effect, says KNKX weather expert Cliff Mass.


Why March was colder than January this year

If you’ve been feeling chilly lately, you are not alone. Lots of people may have noticed on walks around their neighborhoods that spring this year has been colder than usual. And in fact, now that March is over, statistics show the month has been colder on average than January.


Decline in aircraft traffic could degrade West Coast weather forecasting

Sprinkles and showers are in the forecast for most of Western Washington this weekend, with temperatures hovering around 50 degrees. It’s perfect weather for gardening or maybe taking a long run or walk in your neighborhood. The skies above likely will be quieter, too. The spread of the new coronavirus already has slowed air traffic aloft. An even more dramatic decline in commercial flight schedules is coming soon. And that could affect weather forecasting.