An ominous forecast from the National Weather Service calls for strong northerly winds gusting up to 50 mph over the North Bay mountains starting late Wednesday afternoon and continuing overnight.

Winds won’t be quite as strong as the 60 mph blasts that propelled the Tubbs fire over the mountains from Napa County into Santa Rosa early Monday, a weather service meteorologist said, but still cause for worry in a region with nerves rubbed raw for three days.

Firefighters are paying close attention to the forecasts and conditions Wednesday as the day turned breezy in late morning

“The first winds event was expected at 10 a.m. and the meteorologists nailed it. It started at 10 a.m.,” said Jack Piccinini, the Windsor and Rincon Valley fire chief.

The early wind was north to northwest, “a little bit in our favor,” he said.

More concerning is an easterly wind due to kick in between 4 p.m. and 6 p.m., he said.

At the Sonoma County Fairgrounds fire base camp, wind picked up around 10:30 a.m., said Paul Lowenthal, a spokesman for the Santa Rosa area fire.

“It’s getting a little more consistent,” he said about 1 p.m., noting that palm trees were swaying at fire-ravaged Journey’s End Mobile Home Park in Santa Rosa.

The red flag warning and wind advisory calls for northeast winds in the mountains from 20 to 30 mph with gusts over 50 mph from 5 p.m. Wednesday to 5 p.m. Thursday.

Winds are expected to “ramp up” between 9 p.m. and 11 p.m., meteorologist Brian Garcia said.

The warning applies to the mountains between Napa and Sonoma counties and the hills flanking Sonoma Valley, as well as the mountains in eastern Napa County.

The warning also applies to the mountains in northwest Sonoma County, noting that any fires that develop will spread rapidly.

In the Sonoma County valleys, including Santa Rosa, winds are expected to range from 8 to 13 mph Wednesday, picking up slightly in early evening, Garcia said. Overnight, the valley may be calm, with winds picking up toward sunrise, he said.

You can reach Staff Writer Guy Kovner at 707-521-5457 or guy.kovner@pressdemocrat.com. On Twitter @guykovner.