Gusty Offshore Winds and Dry Conditions for Interior North Bay

Mountains Wednesday night through Thursday morning.

A shift towards a drier air mass and offshore flow will lead to

locally critical fire weather conditions across the interior

North Bay Mountains tonight through Thursday morning. Locally

gusty north to northeast winds overnight will coincide with poor

humidity recoveries. Winds are expected to diminish through the

day Thursday, but widespread critically dry humidities will

prevail throughout the day. The areas of greatest concern are

locations in Napa County and into interior Sonoma County at or

above 1000 feet including the Vaca and Mayacamas ranges. These

areas will see the strongest winds, lowest humidity, have the

driest fuels, and they received little to no wetting rainfall

earlier this week.

RED FLAG WARNING IN EFFECT FROM 11 PM THIS EVENING TO 11 AM

PDT THURSDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR

INTERIOR NORTH BAY MOUNTAINS...

The National Weather Service in San Francisco has issued a Red

Flag Warning for gusty north to northeast winds and low humidity,

which is in effect from 11 PM this evening to 11 AM PDT Thursday.

The Fire Weather Watch is no longer in effect.

* AFFECTED AREA...Fire Weather Zone 507 North Bay Mountains

  focused on the Vaca and Mayacamas ranges in Napa County and

  including the border area of Sonoma and Napa counties

* TIMING...11 PM Wednesday to 11 AM Thursday.

* WINDS...North 15 to 25 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...As low as 8 to 15 percent during the day

  with poor recoveries overnight ranging only 15 to 30 percent.

* TEMPERATURES...In the lower 70s.

* IMPACTS...Any fire starts would likely see rapid spread due to

  dry fuels, low humidity and gusty winds in areas that did not

  receive wetting rains over the weekend.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Red Flag Warning means that critical fire weather conditions

are either occurring now...or will shortly. A combination of

strong winds...low relative humidity...and warm temperatures can

contribute to extreme fire behavior.