Saturday to be among heatwave’s hottest, but relief in sight

Saturday is expected to be one of the hottest days of the current heatwave — now five days running — with triple-digit temperatures expected to bake parts of the North Bay, the Central Valley and much of the Western United States.

With the morning fog gone, temperatures in Sonoma and Napa counties are beginning to climb.

The northern part of Sonoma County is expected to see temperatures range from 105 to 110, while Northern Napa County could reach between 110 and 114, said Rick Canepa, a meteorologist with the National Weather Service.

Santa Rosa is likely to hit a high of 101 degrees and Napa should reach 98, he said.

“It’s still quite toasty aloft, in the lower levels of the atmosphere especially,” Canepa said. “Once you get the sun to connect with that we’re looking for temperatures to take off pretty quickly again today.”

The current heat advisory from National Weather Service extends through 11 p.m. Wednesday. A red flag warning for the North Bay interior mountains and other part of the Bay Area is set to expire tonight at 9 p.m.

Canepa said temperatures in the North Bay will fall just short of daily records set in 1921, when Santa Rosa hit 104 degrees and Napa and Kentfield reached 106 and 107, respectively.

This weekend’s heatwave is expected to be even worse in the Sacramento Valley, where temperatures could range between 113 in Sacramento to 120 in Redding, according to Weather Service predictions.

Early Saturday morning, weather service officials there had been “some improvement” in next week’s forecast, with temperatures expected to begin cooling Sunday and through Tuesday.

The region, however, will continue to be above normal through the week, but most locations will stay under 100 degrees, officials said.

If that forecast holds, the weather service could revise its current heat advisory.

“However, we don't want to send mixed messages during the peak of the event,” weather officials said Saturday in their latest weather update. “As such, we don't plan to make any changes to the current warnings until Monday.”

You can reach Staff Writer Martin Espinoza at 707-521-5213 or martin.espinoza@pressdemocrat.com. On Twitter @pressreno.