The National Weather Service has issued a Red Flag Warning for the interior North Bay mountains from Wednesday night through Thursday evening because of critical fire weather conditions that are expected to develop.
Low humidity and northerly winds with gusts of up to 35 mph could cause fires to rapidly grow if they spark, which prompted the Red Flag Warning that will be in effect between 11 p.m. Wednesday and 5 p.m. Thursday. The warning includes parts of Napa and Sonoma counties as well as areas further north, according to the weather service.
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No major wildfires were burning in the Bay Area as of Wednesday afternoon, but, causing the Bay Area Air Quality Management District to issue a Spare the Air alert banning the burning of wood through Thursday.
The weather service said the warning "remains a marginal, lower end Red Flag event" and that relief from the smoke will likely come Friday as winds shift westerly.
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