Northerly winds blowing at regular speeds of 20 to 35 mph with gusts up to 50 mph are expected for the weekend, according to the National Weather Service. The forecast led to a “red flag warning” for Sonoma County, the rest of the North Bay and the East Bay hills from 10 p.m. Friday to 10 a.m. Sunday.

A red flag warning is the highest alert level for fire danger from the California Department of Forestry and Fire Protection, Cal Fire. Los Angeles and Ventura counties, the location of the current Thomas Fire, have been under red flag warning status for the past 12 days, the longest sustained period of fire weather warnings on record.

The dry, gusty winds expected over the weekend have triggered fire concerns at higher elevations in the North Bay mountains. But this is expected to be a more moderate wind event, not as strong as the high winds – up to 100 mph – that occurred the night of Oct. 8-9.

The winds may result in branches or trees falling onto or blocking roadways, and drivers are advised to proceed with caution.

Areas burned in October fires are less susceptible to reigniting should a fire escape or a utility pole blow over, though there are still unaffected areas within the fire perimeter that could pose a risk, officials said.

Yet concerns remain because the rainy season has started off slow with the precipitation level 58 percent of normal around Santa Rosa, said National Weather Service Meteorologist Anna Schneider.

The lack of rainfall, low humidity, dry winds and unseasonably high temperatures all lead to a “prolonged period of critical fire whether,” Schneider said. Even though many on the North Coast felt chilly mornings in the mid-30s, afternoons have typically increased to around 70 degrees, Schneider said.

There’s a chance of rain mid-week, but “the models have been inconsistent, so if that doesn’t happened it won’t rain for a while,” she said.

The National Weather Service cautions people to be extra vigilant about fire safety during a Red Flag Warning. Among their recommendations are:

  • Never mowing or trimming dry grass on a Red Flag Warning Day.
  • Never burning landscape debris like leaves or branches on No Burn Days or when it's windy.
  • Avoid any outdoor burning and be extra vigilant about fire safety.

“You should never start a fire when winds are above 10 miles per hour,” said Cal Fire and Napa County Fire Capt. Chase Beckman.

Residents are advised to have an emergency plan set up, and to sign up for SoCo Alerts at www.socalalert and Nixle at www.nixle.com to receive emergency updates on mobile devices.