That typical fall weather pattern with dry winds pushing west is forecast to develop in Northern California Tuesday into Wednesday and heighten wildfire risk to critical levels. The most severe offshore winds are expected overnight and the National Weather Service is calling on people to stay aware and monitor any fire activity in their area, while Pacific Gas & Electric is preparing to potentially cut power to 20,142 customers in 17 Northern California counties on Tuesday night, after in-person voting has wrapped up.

"Many everyday things can spark wildfires, " the weather service warned. "Keep ignition sources far away from dry vegetation, wood and other fuel."

The winds are expected to pick up as a cold, dry low-pressure system drops down from Canada and digs into the Four Corners region. Meanwhile, a high pressure system is building into the Pacific Northwest and that's causing what's known as a pressure gradient to tighten. "The difference in the high pressure and low pressure leads to stronger winds," Nicole Sarment a meteorologist with the National Weather Service, said.

The Bay Area is expected to see some of the most extreme conditions and highest wildfire risk in Northern California. "This system is really set up to give the worst to us, especially with the way the gradient is centered with the upper level trough digging in ... it's really set up to give us the offshore winds," Rachel Kennedy, a forecaster with the weather service's Bay Area office, said.

While far Northern California saw a few rounds of rains in October that wetted vegetation and lowered wildfire risk, the Bay Area has seen little rain.

"The one caveat I'll make to that is the North Bay received about an inch since the water year began in October," Kennedy said. "Last week, we had a couple rounds of wetting rain up there, which helps, but really won't have any substantial effect during this event considering the winds we're going to get and how quickly they will dry things out."

The Bay Area has seen some of its biggest and most damaging wildfires -- including the 2019 Kincade Fire and the 2017 wine country fires -- when offshore winds have developed. Kennedy said this event is unlikely to be as extreme as those in 2019 and 2017, but will "be one of the stronger events we have seen in many years."

In the Bay Area, the height of the blustery conditions is expected Tuesday night into Wednesday with sustained winds of 20 mph to 30 mph and isolated gusts up to 50 mph are forecast. A red flag warning is in effect for most portions of the region from 11 a.m., Tuesday to 7 a.m., Thursday. The Bay Area weather service is calling on people to "stay aware and monitor active wildfires" in their area. "Keep track of any alerts or orders coming from local law enforcement," the agency said. "If you need to evacuate, leave early."

Kennedy advised people living in wildfire-prone areas to make sure they sign up for alert systems and program their phones so they can hear any alerts that come through during the overnight hours. "Make sure you have as many ways as possible to access those warning systems," she said.

The North Bay will see the strongest winds in the Bay Area with gusts up to 70 mph likely knocking Mount St. Helena. a wind advisory 4 p.m. Tuesday to 3 p.m. Wednesday. The weather service issued a wind advisory for interior mountains of the North Bay from 4 p.m. Tuesday through 3 p.m. Wednesday.

The weather service's Sacramento office is also sounding the alarm bells and issued a red flag warning for the Delta area and the western Sacramento Valley 10 a.m. Tuesday to 4 p.m. Wednesday. Northerly winds of 20 to 30 mph with gusts of 40 mph to 50 mph are expected to pummel the region.

The winds come at a time when the region has seen little rain and vegetation on the ground is parched and highly flammable. What's more, the low-pressure system will pull dry air into the region, leading to plummeting humidity levels. It's a perfect recipe for wildfire starts and rapid spread and PG&E is preparing for the worst intentional power shutoffs. The utility company said most of the customers who could be put in the dark are located in the North Bay and East Bay of the Bay Area and in the Sacramento Valley. The shutoffs are a preemptive measure to de-energize equipment that can get knocked over and damaged in strong winds and send off sparks that start wildfires.

Five polling locations may be blacked out but not until after in-person voting has wrapped up as PG&E said outages across Northern California will occur at 7 p.m. at the earliest. The potentially impacted polling locations include include Girl Scout House, Orchard School and Moose Lodge in Solano County; Calpine Geothermal Visitor Center in Lake County; and Lakeside Elementary School in Santa Clara County.