The National Weather Service has issued a Red Flag Warning for North Bay mountains effective Monday, Sept. 23 at 9 p.m. through Wednesday morning. A Red Flag Warning means that critical fire weather conditions are either occurring now or will shortly. A combination of strong winds, low relative humidity and warm temperatures can contribute to extreme fire behavior.
Building high pressure will result in gusty offshore winds developing late this evening which would bring critical fire weather conditions over the North and East Bay Mountains/Hills through early Wednesday morning. Additionally, hot afternoon temperatures on Tuesday and Wednesday along with low humidity
values in the teens will contribute to increased fire danger.
• Affected area: The North Bay Mountains, East Bay Hills and
Diablo Range above 1000 feet. Fire weather zones 507 and 511.
• Wind: North to northeast winds 10 to 25 mph with gusts 30 to
35 mph. Locally higher gusts to 40 mph in the North Bay
Mountains possible, particularly in Sonoma and Napa counties.
• Humidity: Widespread minimum daytime humidity values in the
teens to low 20s. Overnight recoveries of 30 to 50 percent.
• Highest threat: North Bay Mountains, particularly the peaks
and ridges in Napa County.
• Impacts: Any fires that develop will have the potential to
spread rapidly.
Report any sign of smoke to 911.
Do not do any outdoor burning, including fire pits.
Do not use power tools in or around vegetation.
Do not drive onto dry grass.
Use caution when using barbecues.
Ensure that you are registered to receive emergency alerts via SoCo Alert and Nixle.
Keep close tabs on the weather and weather forecasts.
