The National Weather Service - Bay Area (Saturday afternoon) warns that dry lightning and erratic winds caused by thunderstorms expected Sunday morning could spark new wildfires.
A moist and unstable midlevel airmass is forecast to spread north across the region during Sunday. As that takes place, isolated to scattered thunderstorms may develop over Mendocino and Lake counties early Sunday morning and then spread north during the remainder of the day. Additional thunderstorm development will be possible during Monday as remnants of a tropical storm move north across the area. Another round of storms will be possible during Tuesday morning as a second upper disturbance ejects eastward across the region. Lightning combined with dry fuels will increase the threat for fire starts during each episode of storm development.