The National Weather Service has issued a Fire Weather Watch for much of Northern California beginning Thursday at 11 am, including most of the Bay Area as well as the Sacramento Valley.

Strong offshore winds are being forecast starting Thursday morning and continuing through Saturday night, as the annual rounds of seasonal Diablo winds kick up, raising the risk of wildfires. The weather service is predicting 40 mph winds starting Thursday at 11 am, with isolated gusts of up to 50 mph, and a Red Flag Warning is likely to follow.

Low humidity throughout the end of the week also raises wildfire risk.

And for this forecast, unusually, the city of San Francisco is included in the Fire Weather Watch.

"Folks, we are not out of the woods yet," the National Weather Service tweeted Monday. "We've issued a Fire Weather Watch in effect Thursday until Saturday evening for the potential for strong offshore winds and low humidity."

A lot of vegetation around the Bay is also in a pretty crispy state after the heatwave of a week ago, which is another factor that could lead to increased probability of wildfires breaking out.

The weather service says that higher elevations, like the hills of the East Bay and the ridges that run through Napa and Sonoma valleys, will be likeliest to see the strongest wind gusts — and a Red Flag Warning could very well be in their future.

Some of the Bay Area's worst wildfires have occurred in October, including the 2017 Tubbs, Nuns, and Atlast fires, which broke out the first week of the month, and the Oakland Hills firestorm, which broke out on October 19, 1991.

During the outbreak of the 2017 fires, wind gusts of 50 to 70 mph were recorded along the Napa and Sonoma ridgelines, which helped fuel some very fast-moving blazes.

Like the so-called Santa Ana winds in the southern part of the state, the Diablo winds are caused by the compression of air as pushes down to sea level from higher elevations in Utah and Nevada to our east. The weather pattern, common here in October and November, creates strong off-shore windflows that are the reverse of our usual onshore breezes, and these can last for multiple days — as will reportedly be happening later this week.

Fallen power lines were the culprit in the 2017 fires, as well as in the devastating Camp Fire in Paradise a year later, with sparks fed by the strong winds. However everyone must take precautions to avoid barbecue sparks, discarded cigarettes, any sort of bonfires, or even lawnmowers hitting rocks that have been known to spark significant blazes.