Turn, turn, turn goes the weather, bringing sun, and uncertainty

Apr 20, 2012

April showers will dry out today, and by Saturday, most of western Washington should see sunshine. But, we're not so sure about Sunday.

That's the word from KPLU weather expert Cliff Mass, of the University of Washington. He says the promise of 70-degree temps on Sunday need to come with a caveat, because of a band of clouds that will setup along the Washington coast. If those clouds drift inland at all, then it'll turn into a gray and slightly cooler day.

"Sunday's a difficult forecast, and it can go both ways," he says.

And the uncertainty continues into Monday. If you want a guarantee of warmth and sun, head east across the mountains, or to Portland, where it's almost sure to be in the 70's.

That's all pretty typical of April, says Mass.

"The spring is the most unstable time of year. That means this is the time of year we tend to get a lot of convection ... this shower and sunbreak type of regime," he says. It's the big difference in temperature between the ground that's heating up and the air that's still cold that causes the atmosphere to stir itself like a pot on a stove.

Get the details in the weekly interview.

Do you have a weather question? Cliff Mass and Keith Seinfeld occasionally answer reader questions on the air. Share yours here.

The weekly KPLU feature "Weather with Cliff Mass" airs every Friday at 9 a.m. immediately following BirdNote, and repeats twice on Friday afternoons during All Things Considered. The feature is hosted by KPLU’s Science and Health reporter Keith Seinfeld. 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.