After nearly three weeks of wet weather that was making it look like this month might shape up to be one of the rainiest Aprils on record, sunshine is on its way to the Pacific Northwest. KNKX weather expert Cliff Mass says there’s one last rainy stretch to get through late Friday, but after that, real spring warmth and strong sun is on the way.
“You’re going to need gallons of sun screen,” said Mass of the weather in the week ahead, “so… be ready.”
One More Rainy Stretch - Friday Night
He said Friday morning there was a weather system offshore that was coming in very slowly. This all adds up to partly cloudy and reasonably warm weather.
“With considerable sun, temperatures getting up to around 60 in most of Western Washington – so really quite a decent day,” Mass said.
But he says later in the day, the clouds will thicken.
“And overnight, there’s going to be rain,” he said.
“A frontal system is moving through, the winds may pick up a bit. That rain is going to extend into the beginnings of Saturday.
"So Saturday morning, there could still be some showers around. And then we’re going to transition to partly cloudy skies later in the day. And I suspect tomorrow will get up to maybe 58 to 60, something like that.”
Warm Sun Starting Sunday
Mass says Sunday, things are going to start drying out even more, with party cloudy skies again and temperatures around 60.
“But then things change,” Mass said.
People will start to experience sunshine that is nearly as strong as we get in August.
Really Warm Next Week
“High pressure really pushes in. We even get some offshore flow,” he said. “And temperatures are going to surge next week, on Monday in the upper 60s. Then as we get into Tuesday, Wednesday, Thursday, I think we’re talking about 70 in many places away from the water. So we’re going to be way up there.”
Mass says at this time of the year, the average high is around 59 at Sea-Tac.
“So we are going to be 10 degrees above normal,” he said. “So, it’s all over, you know, just got to get through this one frontal system tonight and then we’re going to get into warm, spring weather.”
A Record Wet April? Probably Not
The upcoming weather stands in stark contrast to what people in the greater Puget Sound region experienced just last weekend.
“Saturday was very wet,” Mass said.
”We had a potent atmospheric river, this current of strong moisture, that narrow current -- a lot of moisture coming in right at us."
He says in Seattle some places had one-and-a-half to two inches. But that wasn’t the wettest place.
“In the mountains, where that plume of moisture went uphill, three to five inches -- a number of locations had their all-time record daily precipitation, for that day,” Mass said.
He says for the month as a whole, though, it isn’t looking like this month will shatter any records.
“Right now we’re about the fourth wettest April on record,” Mass said.
“I don’t think we’ll beat the record, which is about six and a half inches. But this is definitely in the top five wet Aprils in history.”
To hear the full conversation, including Cliff’s explanation of why the sun is becoming so strong right now, 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.
Mass also organizes an annual conference about weather science at NOAA Seattle. The Northwest Weather Workshop is coming up, on April 27-28. It is open to everyone, but you need to register ahead of time. Here's the link with information on how to do that: