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Scorching temperatures, smoky skies predicted in Bay Area this week, National Weather Service says

By Aldo Toledo, The Mercury News on

Published in News & Features

SAN JOSE, Calif. - Bay Area residents are in for a tough week, with a high-pressure system threatening to keep temperatures in the sweltering range and hold wildfire smoke in the air overhead.

National Weather Service meteorologist Gerry Diaz said hot and dry conditions are expected for much of the area throughout the week, with peak temperatures expected Sunday and Monday.

The forecast raised alarms over the potential for new wildfires as hundreds of firefighters continue to battle blazes across the state. On Sunday, the Glass fire in Napa forced evacuations shortly after it broke out in the morning.

"A lot of the fire risk is not so much to do with temperature but rather air mass," Diaz said. "There's a dry air mass moving in from the desert. When you have offshore winds coming from the northeast, it's those strong winds and dry conditions that help create an environment that's suitable for wildfires."

Diaz said the immediate concerns for wildfires are the high temperatures in the inland valleys. Napa was set to hit 100 to 102 degrees on Sunday, and cities in the Tri-Valley were expected to reach 104 degrees.

Diaz said smoke from the Napa fire could impact air quality in the North Bay, San Francisco and the East Bay as it grows. Air quality conditions will be best in the South Bay early this week, Diaz said, as San Jose isn't likely to see much smoke, Diaz added.

"But we have active wildfires so the smoke may permeate into the South Bay," Diaz said. "Unfortunately there's also the concern of new fires like what we're seeing this morning. I hate to be the bearer of bad news but the general idea is hot weather and potential for more wildfires."


In San Francisco, the west-facing ocean side of the city will be over 20 degrees cooler than the denser urban core along the bay. Temperatures in the Sunset are expected to be in the mid 70s, while the Financial District could see temperatures in the high 90s.

In the East Bay, Oakland and east Contra Costa County communities could see temperatures as high as 90 degrees. South Bay communities will see temperatures ranging from 90 to 97 degrees.

Diaz added that a layer of high pressure that's sitting over the Bay Area is "not moving all that much" so warm temperatures could stick around for a while and make smoky conditions even worse if smoke from blazes like the Glass Fire and others around the state head into the bay.

As of Sunday morning, air quality in the Bay Area was good, with some ozone pollution in south and east San Jose with forecasts predicting moderate air pollution starting Monday.

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