thunderstorms

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Labor Day marks summer’s unofficial finale, and KPLU weather expert Cliff Mass says the warm weather with make a curtain call this weekend, though the beach-and-barbecue weather will be a memory by Monday.

"Today is the transitional day,” says Mass, a professor of atmospheric sciences at the University of Washington.

Hang in there—the feel of Seattle's great summers is coming back this weekend.  

The autumn-like weather we’ve been having this week will yield to more typical summer fare, with blue skies in the afternoons and temperatures in the 70s, says KPLU weather expert Cliff Mass.

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Today we’ll get plenty of sun and temps in the upper 70s to lower 80s, but clouds and precipitation are moving in for the weekend, says KPLU weather expert Cliff Mass.

“An upper-level low is approaching us from the Southwest right now,” said Mass, professor of atmospheric sciences at the University of Washington. The clouds and rain that are already in Oregon are going to move northward.

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Sick of the dreary weather? Fear not—a big change is coming, says KPLU weather expert Cliff Mass.

“The cold and rain is going to turn into warmth and sun pretty soon,” says Mass, a professor of atmospheric science at the University of Washington.

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"This is the summer of thunderstorms," says Cliff Mass, KPLU weather expert and meteorologist at the University of Washington.

An unusual pattern of low pressure keeps recurring over the western U.S., bringing the rain and lightning. Temperatures are about ten degrees below normal for this part of July--which is typically the sunniest part of the year in the Puget Sound area.

East of the mountains, there have been two flash floods, as of this morning.

Greg Johnson / www.skunkbayweather.com

If you were in the mountains or northern Puget Sound last night, you may have seen some spectacular lightning bolts and thunderstorms. Those are rare in the northwest, compared with the midwest. But KPLU weather expert Cliff Mass says the right conditions are here now, and will be with us through Saturday.

Mass, a professor of Atmospheric Science at the University of Washington, explains why, in this week's interview.