“Unusually Sunny Midwinter” Yielding To More Typical Clouds And Rain | KNKX

“Unusually Sunny Midwinter” Yielding To More Typical Clouds And Rain

Jan 5, 2018

Rain and cloudy skies have returned to much of the Puget Sound region. KNKX weather expert Cliff Mass says Western Washington can expect more of this showery, gray weather over the next few days. But that’s in contrast to what has actually been a much sunnier winter than usual in the northwest.

Second Sunniest Mid-Winter Since 2000

Remember those bright sunny days and long stretches of dry weather in early December? They added up.

“This year has been much better than the last few years in terms of the amount of sun that we’re seeing,” said Mass, a professor of atmospheric sciences at the University of Washington.

He says data on solar radiation measured at the surface around the region tells the story.

“December was quite a bit sunnier than most,” Mass said.  “In fact, it was the second sunniest late-fall, early-winter since 2000. So, we’ve had considerable sun.”

He says that was particularly true during the first weeks of December,

“It was really amazing,” Mass said. “And then even the last week, we’ve had a number of days with a lot of sun.”

Mass says the cause of that kind of weather is typically high pressure that builds in above us and causes sinking air that makes clouds dissipate.

Typical ‘Blah Pattern’ Forecast Ahead: Clouds And Showers  

The forecast over the next few days isn’t sunny.

“I’m afraid we’re going to have some clouds and showers over the weekend,” Mass said. “Nothing too serious.”

He said a weather system was moving through on Friday, bringing in precipitation that’s common this time of year.

“So we’ll have light to moderate rain, temperatures getting up into the mid-40s, clouds – just the typical stuff.”

Mass says expect more showers Saturday morning.

“I think they’ll kind of fade out as we get into the afternoon, there’ll probably be a convergence zone somewhere between Seattle and Everett,” he said, referring to the typical area of rain that occurs when westerly winds split by the Olympic Mountains come back together over Puget Sound.

Mass says the showers should die down by Saturday evening, with temperatures reaching highs of 45-46 degrees.

“So another very typical day,” Mass said.

He says Sunday will start off dry, but then another weather system comes in. 

“I expect precipitation to be moving in by the afternoon, light to moderate rain, temperatures getting up to 46-47,” he said.

Next week, Mass says expect more of the same.

“We just have a pretty blah pattern of temperatures: mid to upper 40s and showers on and off,” he said. “So nothing exciting, no big windstorms, snowstorms or anything else next week.”

To hear the full conversation – including Cliff’s take on the “bomb cyclone” that hit the U.S. East Coast this week  – you can 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.