This Weekend's High Temps, Sunny Skies Pushing Toward Record-Breaking Summer

Aug 8, 2014

Go ahead and gloat. We’ve got one of those hot, sunny August western Washington weekends ahead that make it worth living here despite the long, dark winters.

Low clouds will melt away, says KPLU weather expert Cliff Mass, as temperatures steadily rise over the weekend, hitting 90 maybe even as early as Sunday and certainly by Monday.  

“A warming period is going to happen,” said Mass. “And that’s because a trough that brought us cooler temperatures this week is moving off and a pretty high-amplitude ridge is building in its place.”

Historically Warm Summer For The Northwest

Mass says it will be even hotter than normal as this summer shapes up to break historical records.

“July, for a number of cities in Washington, has been the number one month in terms of average temperatures. A lot of stations in eastern Washington — Wenatchee, Yakima and Spokane — have had their warmest July on record,” Mass said. “Seattle had its second-warmest July on record. So this is kind of unusual. And it’s been persistent for the last month, and it’s not going away.”

Mass says temperatures will be above-normal for the next week or two as well.

“That’s pretty much in the cards,” he said.

Warmer El Niño Winter Ahead

As the summer looks like it will be historically warm, Mass expects the winter ahead to be mild here as well. He says it’s looking more and more like an El Niño year.

“The models we have that simulate the sea temperature in the Pacific are pretty emphatic,” Mass said.

Mass, who tracks those models closely, says it won’t be extreme, but it will mean a slightly warmer than average winter with a little less precipitation and less snow in the lowlands and mountains.

“At one point, it looked like it was going to be a super-duper El Niño  with extraordinarily warm temperatures in the Pacific,” Mass said. “Now it looks like it will just be a sort of regular El Niño, where the warm temperatures in the Pacific cause the weather in the Northwest to be a little different than average.”

That means potential challenges for water management in the Northwest, as the snow pack that serves as storage could be lower. But it’s good news for drought-stricken California, because El Niño often brings heavier precipitation to the southern and central part of that state. El Niños tend to split the jet stream, sending more of it southward.

“That could be an extraordinarily welcome event,” Mass said. “They desperately need more rain down there, and having El Niño weights the dice for them getting more precipitation at the same time we get less precipitation.”

Hurricane Connection?

Mass says many people have been asking him if the El Niño predictions might be connected to the rare occurrence of hurricanes that are hitting Hawaii. El Niños often cause more tropical storms and hurricanes. A hurricane hasn't hit Hawaii in 22 years, and this week, it's facing two. Still, Mass doubts the connection.

“I don’t think we can blame the two hurricanes that are bearing down on Hawaii right now on El Niño,” Mass said. He says the temperatures in the Pacific Ocean are currently warmer than normal, which does help power up the hurricanes a bit. But he says the water’s not quite warm enough to convince him.

Two Reasons Why Hurricanes Are So Rare in Hawaii

“Hurricanes like warm water,” Mass said. The magic number is 26 degrees centigrade, he says, and often it’s cooler than that in Hawaii. “Go in the water there and it’s just not as warm as, let’s say, the Caribbean.”

The other reason is Hawaii tends to get a lot of wind shear.

“The wind changes height quite a bit above Hawaii. And that’s bad for hurricanes. It tends to tear them apart,” he said.

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The weekly KPLU feature "Weather with Cliff Mass" airs every Friday at 9 a.m. immediately following BirdNote, and twice on Friday afternoons during All Things Considered. The feature is hosted by KPLU 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 a podcast of “Weather with Cliff Mass” shows.