For those drawing the drapes against the Bay Area's heat wave, don't open them yet. Hotter temperatures are on their way.

Just in time for autumn, the state's seasonal guest is arriving with scorching heat and barely a breeze.

The offshore flow pattern, in which air masses originating in the Great Basin east of the Sierras sweep westward before heating up as they descend, will bring temperatures in the mid-90s today, peaking in the 100s on Tuesday, the autumn equinox. It's the Northern California equivalent of Los Angeles' fire-fanning Santa Ana winds.

"There won't be any marine air," which normally cools the Bay Area, said meteorologist Rick Canepa with the National Weather Service. Expect the heat to linger late into the week, maybe cooling into the upper 80s on Thursday or Friday, he said. "It's not really going anywhere fast."

On Sunday, the highs were 90 degrees in San Jose, 92 in Los Gatos and 95 in Los Altos. Today, highs are expected to reach 94 in San Jose and Mountain View, and the upper 90s in the West Valley and in South County.

Contact Sharon Noguchi at 408-271-3775.

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