Weather with Cliff Mass | KNKX

Weather with Cliff Mass

"Weather with Cliff Mass," is our weekly feature about Pacific Northwest weather hosted by KNKX's environment reporter Bellamy Pailthorp. Every week Bellamy talks with University of Washington Professor of Atmospheric Sciences and renowned Seattle weather prognosticator Cliff Mass about the weekend weather and a weather-related topic.

Listen every Friday at 9 a.m. following "BirdNote." You can hear repeats twice on Friday afternoons during All Things Considered at 3:45 and 5:45, and once on Weekend Edition Saturday at 7:35 a.m. 

A view from Seattle on May13, 2020.
Tim Durkan / Tim Durkan Photography

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.

Mount St. Helen's erupts on July 22, 1980 in Washington State.
JACK SMITH / The Associated Press

“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.

Editor's note: The following review is in response to members of the community who raised concerns about our weekly "Weather with Cliff Mass" segment. This public editor review is half of a two-part process that included a scientific review, which you can download and read here.

A view "from Seattle with love" on May 14, 2020.
Tim Durkan / Tim Durkan Photography

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.

Tim Durkan / Tim Durkan Photography

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.

Tim Durkan / Tim Durkan Photography

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.

Tim Durkan / Tim Durkan Photography

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. 

A view of Pike Place Market with Seattle's Elliott Bay on April 15, 2020.
Tim Durkan / Tim Durkan Photography

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."

Tim Durkan / Tim Durkan Photography


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. 

Seattle's skyline, as seen on March 29, 2020.
Tim Durkan / Tim Durkan Photography

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.

The decline in commercial aircraft traffic due to the new coronavirus will degrade weather forecasting, says Cliff Mass, a professor of atmospheric sciences at the Univeristy of Washington.
Ted S. Warren / The Associated Press

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.

A Seattle Sunset as seen on March 18, 2020.
Tim Durkan / Tim Durkan Photography

The official start of spring comes a little early this year, in tandem with the vernal equinox that showed up in most U.S. calendars on March 19. Although meteorological spring began in the Pacific Northwest about a month ago with signs of warmer weather, KNKX weather expert Cliff Mass says around now is when certain typical features of spring become evident.

Mount Rainier showing off March 8, with some lenticular cloud action.
Tim Durkan / Time Durkan Photography

Mount Rainier looms on horizons in the region like no other, dominating views when visible – or “out” as locals like to say. This massive 14,000-foot peak is an active volcano that inspires awe in visitors to the region and stands as one of our most recognizable icons.

It also has a profound effect on the weather around it – because of its size.

An early springtime view of Port Townsend Bay , as seen from the Larry Scott memorial trail on March 1, 2020.
Bellamy Pailthorp / KNKX

Do you doubt that spring has arrived in the Pacific Northwest? With cool temperatures and copious rain dousing much of the region lately, it can be hard to believe.

Just a couple of weeks ago, KNKX weather expert Cliff Mass talked about the typical arrival of "meteorological spring," when big storms cease and other weather changes indicate that for all practical purposes, winter has ended. It happens here a full month prior to the end of winter on the East Coast.

A view from Seattle on Feb 21, 2020.
Tim Durkan / Tim Durkan Photography

People in Western Washington have enjoyed plenty of mild, warm days and sunshine lately — typical weather for late winter and early spring. Suddenly, we’re shedding layers and searching for our sunglasses.

But in Eastern Washington and Oregon, early spring marks the onset of what can be a terrifying phenomenon: Northwest dust storms that dramatically reduce visibility and air quality when winds pick up.

A view from Seattle on Thursday, Feb. 20, 2020.
Tim Durkan / Tim Durkan Photography

The mornings have been cold and crisp under clear skies this week in many parts of the Pacific Northwest, with lows around freezing in places. But powerful sunbeams have pushed afternoon highs into the pleasant realm of the 50s.

KNKX weather expert Cliff Mass says this is in keeping with what he calls “meteorological spring,” when the weather stops delivering storms and cold temperatures that are the hallmarks of winter. Instead, trees and shrubs start sprouting green buds, crocuses push through the soil and people begin shedding layers of clothing needed in colder weather as they enjoy warmer temperatures.

Rain is in the forecast this weekend, but don't worry. Sun is on the horizon starting Monday.
Parker Miles Blohm / KNKX

The rain just keeps coming. Our reservoirs are above normal now, and it looks like there’s more rain on its way all weekend long. But can you trust that forecast? KNKX weather expert Cliff Mass says some weather apps are often the most acurate source — and anyone can check their reliability.

A flood watch continues till 4 o'clock Friday. The National Weather Service says although the rain had tapered down earlier in the morning and most area rivers were expected to crest in the afternoon, flooding will continue into Saturday.

Eleven people were evacuated from an apartment complex in Issaquah Thursday, with standing water causing road closures all around the region. 

This kind of flooding does happen regularly in western Washington, especially in areas that are connected to rivers that drain off the Cascade Mountains.
But KNKX weather expert Cliff Mass says the rainfall people have experienced here this week has been exceptionally intense. It’s because of the angle at which the atmospheric river that’s causing the precipitation has come in.

A pedestrian makes his way along a waterfront as downtown Seattle is partially hidden in a steady rain beyond Monday, Nov. 18, 2019.
Elaine Thompson / The Associated Press

It’s been a wet month in Western Washington, with few breaks from steady, and sometimes heavy, rain.

“We’ve just tied the record for number of rainy days at Seattle and at this point, Seattle got about eight inches of rain so far this month,” KNKX weather expert Cliff Mass said on Friday morning. “Typically, we only have about five and a half. So, it’s been a wet period.”

Tim Durkan / Tim Durkan Photography

Washington’s mountain ranges not only produce spectacular vistas and recreational activities year-round. Their location near the Pacific Ocean also creates a variety of unique weather features that add to the special atmosphere in the Northwest.

“You have to love the meteorology of this region. I certainly do,” says KNKX weather expert Cliff Mass, who teaches atmospheric sciences at the University of Washington and wrote a popular book on the subject.

Bellamy Pailthorp / KNKX

Forecasting technology has come a long way since KNKX weather expert Cliff Mass first got his start in the field. He often marvels at how precisely most events can be predicted, using powerful computers that run ensembles of modeling programs that meteorologists compare before they decide what to tell the public. The aim is helping people prepare, especially for potentially dangerous weather.

But in the Northwest, snow – especially the kind that hit parts of Western Washington this week – is notoriously difficult to forecast. Mass agrees, this past week was a case study in that challenge.

Two people walk through Seattle toward the beginning of last year's big snowstorm. KNKX weather expert Cliff Mass says it's too early to tell how much snow we could get next week, but a half a foot or more is possible Wednesday and Thursday.
Parker Miles Blohm / KNKX

With the first chance of major lowland snow in the forecast since last February’s big snowstorms, people all around the Puget Sound region on stocking up on supplies and getting their snow shovels ready.

But KNKX weather expert Cliff Mass says forecasting snow around sea level here is one of the biggest challenges forecasters face. And at this point, the only thing anyone’s really sure of is that it will soon get very cold.

Time Durkan / Tim Durkan Photography

A recent study named Seattle the No. 1 "gloomiest place in America." The website Bestplaces.net, which ranks locations on all kinds of qualities, created a "gloom index" for the largest cities in the nation, based on weather data during the darkest months of the year.

A pedestrian bundled up against the falling snow walks near Pike Place Market Monday, Feb. 11, 2019, in downtown Seattle. Schools were closed across Washington state as winter snowstorms continued pummeling the Northwest, breaking records. .
Ted S. Warren / AP Photo / file

Shortly after the big snows happened in February, residents of the Puget Sound region were already hearing how the winter storms would be an event to remember and tell their grandchildren about.

As we wrap up 2019, KNKX weather expert Cliff Mass says that event still stands out as the biggest one of the year — despite a lot of other features that add up to a year of extremes.

“It was the coldest, snowiest February that we’ve ever had in western Washington,” says Mass, a professor of atmospheric sciences at the University of Washington.

Tim Durkan / Tim Durkan Photography

If you want to see snow on Christmas in the greater Puget Sound region, you’ll probably have to head for the mountains. Or, close your eyes and dream, as the classic holiday tune suggests.

KNKX weather expert Cliff Mass says this year — as is most common around here — there’s no chance of white stuff over the next week in most places.

The North Cascades Highway closed for the season on Wednesday, as snow filled avalanche shoots alongside it. The annual closure for safety was the latest in more than a decade.
Washington State Department of Transportation.

After the driest November in 43 years, precipitation is finally returning to Washington. The North Cascades Highway closed Wednesday – its latest closure in over a decade. The state Department of Transportation shuts it down annually for safety, after snow fills the avalanche chutes that line the highway. About a foot of snow fell this week above 3500 feet.

The Seattle Space Needle as seen Nov. 30, 2019.
Tim Durkan / Tim Durkan Photography

The dry, cool and sunny conditions that brought extraordinary fall color to the Northwest also have toppled a major record. Seattle charted its driest November in 43 years, with just 1.71 inches of rain – about 26 percent of normal. (Spokane was at 30 percent of normal, with .68).

That’s the driest November since 1976 — a “startlingly dry” year that saw about half of last month’s precipitation, says KNKX weather expert Cliff Mass.

The National Weather Service relies on a network of buoys to collect real-time data about ocean conditions. But they’re prone to malfunction and expensive to maintain.

KNKX weather expert Cliff Mass is working with a company that is offering a potential alternative. Oakland-based Saildrone has a fleet of autonomous sailboats that are loaded with high-tech equipment and can be deployed to collect highly accurate weather and upper-ocean observations.

Streams of clouds skim across the peak of Oregon's Mount Hood, as a darker bank of clouds heads east toward the mountain as seen from Portland on Nov. 22, 2016.
Don Ryan / The Associated Press (file)

Holiday travelers had lots to contend with ahead of Thanksgiving, as an unusual storm known as a "bomb cyclone" hit Southwest Oregon and California Tuesday, reaching speeds of 90 miles per hour in places.

Its effects were felt in Washington on Wednesday.

 Mount Rainer is seen at dawn in this Jan. 2, 2012, file photo, from Seattle, some 50 miles away from the national park.
Elaine Thompson / The Associated Press

Snow levels are dropping over the Cascade mountains. Weather officials are warning that anyone planning to cross the passes before Thanksgiving should be aware of the potential for hazardous conditions. As much as a foot is expected to pile up by Wednesday above 3,500 feet, as the temperature drops.

And it will be cold enough all around the Northwest to store your extra food outdoors if the fridge is overflowing, says KNKX weather expert Cliff Mass. But don’t expect to build a snowman. Only a few snow flurries are expected in the lowlands on the west side.

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