Red Flag Warning issued November 4 at 1:30AM PST until November 7 at 7:00AM PST by NWS San Francisco CA
…RED FLAG WARNING NOW IN EFFECT TUESDAY MORNING THROUGH
THURSDAY MORNING FOR THE BAY AREA AND CENTRAL COAST AS STRONG
OFFSHORE WINDS AND CRITICALLY DRY CONDITIONS ARE EXPECTED TO
DEVELOP…
.Strong north to northeast winds are being observed across the region
as a deep trough moves over the Rockies. These dry offshore winds
are causing the dew point and relative humidity to quickly drop.
Despite the recent rain, regional RAWS stations are reporting 10-
hour fuel moistures have dropped back into the single digits and
continuing to dry. By Tuesday night, encroaching high pressure from
the Eastern Pacific will tighten the gradient and strengthen the
winds. Gusts are expected to reach up to 50 mph across the higher
elevations with RH recoveries in the 30-45% range Tuesday night.
Winds will gradually decrease through the day Wednesday, but with
the RH dropping into the high teens, fire weather conditions will
remain critical through Wednesday night.
The National Weather Service in San Francisco has issued a Red
Flag Warning for critically dry fuels, low humidity, and gusty
winds which is in effect from 11 AM Tuesday to 7 AM PST Thursday.
* 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…North 20 to 30 mph with gusts up to 50 mph.
* RELATIVE HUMIDITY…As low as 14 percent.
* LIGHTNING…None.
* IMPACTS…The combination of gusty winds and low humidity can
cause fire to rapidly grow in size and intensity. Outdoor
burning is not recommended. Despite recent wetting rain, we are
expecting a widespread and prolonged offshore wind event which
will dry fuels out very quickly.
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.
