Red Flag Warning issued November 5 at 7:21PM PST until November 7 at 7:00AM PST by NWS San Francisco CA
…RED FLAG WARNING NOW IN EFFECT THROUGH THURSDAY MORNING FOR
THE BAY AREA AND CENTRAL COAST AS STRONG OFFSHORE WINDS AND
CRITICALLY DRY CONDITIONS DEVELOP…
.We are entering the most critical 12 hours of this event. Strong
offshore winds have arrived across the higher elevations of the
North and East Bay and will spread to the lower elevations and
coastal mountains overnight. 10-hour fuel moisture measurements
are now between 5-10%. North to northeasterly wind gusts will
average between 25 and 50 mph, particularly across the higher
terrain of the Santa Cruz Mountains, East Bay Hills, North Bay
Mountains, as well as interior portions of Napa and Sonoma
counties. In particular, these areas of Napa and Sonoma counties
have an increased likelihood of wind gusts between 60 to 70 mph
starting tonight and continuing through the day on Wednesday.
Afternoon humidity values will range between the single digits and
25 percent. Overnight humidity recovery will be poor between 20
and 45 percent. The combination of the aforementioned winds and
humidity will translate to fires exhibiting a large resistance to
control and thereby creating a hazardous and extreme wildfire
environment. Fire crews and residents are urged to remain abreast
of the weather forecast over the next couple of days.
* AFFECTED AREA…Fire Weather Zone 006 San Francisco, Fire
Weather Zone 502 Marin Coastal Range, Fire Weather Zone 503
Sonoma Coastal Range, Fire Weather Zone 504 North Bay Interior
Mountains, Fire Weather Zone 506 North Bay Interior Valleys,
Fire Weather Zone 508 San Francisco Bay Shoreline, Fire
Weather Zone 509 San Francisco Peninsula Coast, Fire Weather
Zone 510 East Bay Interior Valleys, Fire Weather Zone 512
Santa Cruz Mountains, Fire Weather Zone 513 Santa Clara Valley
Including San Jose, Fire Weather Zone 514 Eastern Santa Clara
Hills, Fire Weather Zone 515 East Bay Hills, Fire Weather Zone
517 Santa Lucia Mountains and Los Padres National Forest, Fire
Weather Zone 518 Mountains of San Benito County And Interior
Monterey County including Pinnacles National Park and Fire
Weather Zone 529 Northern Monterey Bay.
* TIMING…11 AM Tuesday until 7 AM Thursday.
* WINDS…Northeast 20 to 30 mph with gusts up to 50 mph. Across
the North Bay Interior Mountains, gusts up to 70 mph.
* RELATIVE HUMIDITY…Between 10 and 25 percent.
* LIGHTNING…None anticipated.
* IMPACTS…Despite recent rainfall, a long duration offshore
flow event is anticipated. This will result in the rapid
curing of fuels. The combination of strong winds and low
humidity will cause fire to rapidly grow in size and
intensity. Outdoor burning is not recommended and may be
prohibited in some areas.
A Red Flag Warning means that critical fire weather conditions
are either occurring now…or will shortly. A combination of
strong winds…and low relative humidity can contribute to
extreme fire behavior.
