Red Flag Warning 4, NWS San Francisco Bay Area, CA

619 
WWUS86 KMTR 271803
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
1103 AM PDT Fri Oct 27 2023

...NEAR CRITICAL FIRE WEATHER CONDITIONS SATURDAY INTO SUNDAY...

.North-northeast winds are expected to develop early Saturday
morning across the ridges of the North Bay, East Bay, and the
Santa Cruz Mountains. Dry, offshore winds will peak late Saturday
into Sunday morning, which will result in elevated fire weather
concerns. During the overnight hours, offshore winds could mix
down into the interior valleys of the North Bay and East Bay.
Gusts of 30 to 40 mph will be possible with locally higher gusts
up to 50 to 60 mph across ridgetops and higher peaks.

CAZ502-504-512-514-515-280215-
/O.CON.KMTR.FW.W.0004.231028T1200Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
1103 AM PDT Fri Oct 27 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 AM SATURDAY TO 5 PM
PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, Fire
  Weather Zone 504 North Bay Interior Mountains, Fire Weather Zone
  512 Santa Cruz Mountains, Fire Weather Zone 514 Eastern Santa
  Clara Hills and Fire Weather Zone 515 East Bay Hills.

* WINDS...North 20 to 30 mph with gusts up to 45 mph. Highest
  ridgetops and peaks may see gusts up to 60 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 
  20 percent on Saturday and Sunday. Poor relative humidity 
  recoveries overnight in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-280215-
/O.CON.KMTR.FW.W.0004.231029T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
1103 AM PDT Fri Oct 27 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 PM SATURDAY TO 5 PM
PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

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

* RELATIVE HUMIDITY...Minimum relative humidity as low as 15 to 35
  percent on Saturday and Sunday. Poor relative humidity
  recoveries in the 25 to 35 percent range for the interior
  valleys. For the coastal regions, moderate humidity recoveries
  of 50 to 70 percent expected, which will occur Saturday evening
  before further drying overnight.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

328 
WWUS86 KMTR 280113
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
613 PM PDT Fri Oct 27 2023

...NEAR CRITICAL FIRE WEATHER CONDITIONS SATURDAY INTO SUNDAY...

.North-northeast winds are expected to develop early Saturday
morning across the ridges of the North Bay, East Bay, and the
Santa Cruz Mountains. Dry, offshore winds will peak late Saturday
into Sunday morning, which will result in elevated fire weather
concerns. During the overnight hours, offshore winds could mix
down into the interior valleys of the North Bay and East Bay.
Gusts of 30 to 40 mph will be possible with locally higher gusts
up to 50 to 60 mph across ridgetops and higher peaks.

CAZ502-504-512-514-515-281200-
/O.CON.KMTR.FW.W.0004.231028T1200Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
613 PM PDT Fri Oct 27 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 AM SATURDAY TO 5 PM
PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, Fire
  Weather Zone 504 North Bay Interior Mountains, Fire Weather Zone
  512 Santa Cruz Mountains, Fire Weather Zone 514 Eastern Santa
  Clara Hills and Fire Weather Zone 515 East Bay Hills.

* WINDS...North 20 to 30 mph with gusts up to 45 mph. Highest
  ridgetops and peaks may see gusts up to 60 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 
  20 percent on Saturday and Sunday. Poor relative humidity 
  recoveries overnight in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-281200-
/O.CON.KMTR.FW.W.0004.231029T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
613 PM PDT Fri Oct 27 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 PM SATURDAY TO 5 PM
PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

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

* RELATIVE HUMIDITY...Minimum relative humidity as low as 15 to 35
  percent on Saturday and Sunday. Poor relative humidity
  recoveries in the 25 to 35 percent range for the interior
  valleys. For the coastal regions, moderate humidity recoveries
  of 50 to 70 percent expected, which will occur Saturday evening
  before further drying overnight.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

108 
WWUS86 KMTR 281112
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
412 AM PDT Sat Oct 28 2023

...NEAR CRITICAL FIRE WEATHER CONDITIONS TODAY INTO SUNDAY...

.North-northeast winds are expected to develop this morning 
across the ridges of the North Bay, East Bay, and the Santa Cruz 
Mountains. Dry, offshore winds will peak tonight into Sunday 
morning, which will result in elevated fire weather concerns. 
During the overnight hours, offshore winds could mix down into the
interior valleys of the North Bay and East Bay. Gusts of 30 to 40
mph will be possible with locally higher gusts up to 60 to 70 mph
across ridgetops and higher peaks.

CAZ502-504-512-514-515-281915-
/O.CON.KMTR.FW.W.0004.231028T1200Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
412 AM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT SUNDAY FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES
502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, 
  Fire Weather Zone 504 North Bay Interior Mountains, Fire 
  Weather Zone 512 Santa Cruz Mountains, Fire Weather Zone 514 
  Eastern Santa Clara Hills and Fire Weather Zone 515 East Bay 
  Hills.

* WINDS...North 20 to 30 mph with gusts up to 45 mph. Highest
  ridgetops and peaks may see gusts of 60 to 70 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 
  20 percent on Saturday and Sunday. Poor relative humidity 
  recoveries overnight in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-281915-
/O.CON.KMTR.FW.W.0004.231029T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
412 AM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 PM PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR
FIRE ZONES 503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

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

* RELATIVE HUMIDITY...Minimum relative humidity as low as 15 to 
  35 percent on Saturday and Sunday. Poor relative humidity 
  recoveries in the 25 to 35 percent range for the interior 
  valleys. For the coastal regions, moderate humidity recoveries 
  of 50 to 70 percent expected, which will occur Saturday 
  evening before further drying overnight.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

258 
WWUS86 KMTR 281616
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
916 AM PDT Sat Oct 28 2023

...CRITICAL FIRE WEATHER CONDITIONS TODAY INTO SUNDAY...

.North-northeast winds will persist across the ridges of the 
North Bay, East Bay, Santa Cruz Mountains, and the Santa Lucia
Mountains. Dry, offshore winds will peak tonight into Sunday 
morning, which will result in elevated fire weather concerns. 
During the overnight hours, offshore winds could mix down into the
interior valleys of the North Bay and East Bay. Gusts of 30 to 40
mph will be possible with locally higher gusts up to 60 to 70 mph
across ridgetops and higher peaks.

CAZ517-290600-
/O.EXA.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
916 AM PDT Sat Oct 28 2023

...RED FLAG WARNING IN EFFECT UNTIL 5 PM PDT SUNDAY FOR GUSTY
OFFSHORE WINDS AND LOW HUMIDITY FOR ZONE 517...

The National Weather Service in San Francisco has issued a Red
Flag Warning for gusty winds and low humidity, which is in effect
until 5 PM PDT Sunday.

* AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains 
  and Los Padres National Forest.

* WINDS...North 5 to 15 mph with gusts up to 25 mph. Highest 
  ridgetops and peaks may see gusts of 35 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 5 to 15
  percent on Saturday and Sunday. Poor relative humidity
  recoveries overnight in the 15 to 30 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ502-504-512-514-515-290600-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
916 AM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT SUNDAY FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES
502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, 
  Fire Weather Zone 504 North Bay Interior Mountains, Fire 
  Weather Zone 512 Santa Cruz Mountains, Fire Weather Zone 514 
  Eastern Santa Clara Hills and Fire Weather Zone 515 East Bay 
  Hills.

* WINDS...North 20 to 30 mph with gusts up to 45 mph. Highest 
  ridgetops and peaks may see gusts of 60 to 70 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 
  20 percent on Saturday and Sunday. Poor relative humidity 
  recoveries overnight in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-290600-
/O.CON.KMTR.FW.W.0004.231029T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
916 AM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT FROM 5 PM THIS AFTERNOON TO
5 PM PDT SUNDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR
FIRE ZONES 503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

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

* RELATIVE HUMIDITY...Minimum relative humidity as low as 15 to 
  35 percent on Saturday and Sunday. Poor relative humidity 
  recoveries in the 25 to 35 percent range for the interior 
  valleys. For the coastal regions, moderate humidity recoveries 
  of 50 to 70 percent expected, which will occur Saturday 
  evening before further drying overnight.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

042 
WWUS86 KMTR 290548
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
1048 PM PDT Sat Oct 28 2023

...CRITICAL FIRE WEATHER CONDITIONS NOW THROUGH SUNDAY...

.North-northeast winds continue across the ridges of the North 
Bay, East Bay, Santa Cruz Mountains, and the Santa Lucia 
Mountains. Dry, offshore winds will peak tonight into Sunday 
morning, which will result in elevated fire weather concerns. 
During the overnight hours, offshore winds could mix down into the
interior valleys of the North Bay and East Bay. Gusts of 30 to 40
mph will be possible with locally higher gusts up to 60 to 70 mph
across ridgetops and higher peaks.

CAZ502-504-512-514-515-291800-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
1048 PM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT SUNDAY FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES
502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, 
  Fire Weather Zone 504 North Bay Interior Mountains, Fire 
  Weather Zone 512 Santa Cruz Mountains, Fire Weather Zone 514 
  Eastern Santa Clara Hills and Fire Weather Zone 515 East Bay 
  Hills.

* WINDS...North 15 to 25 mph with gusts up to 45 mph. Highest
  ridgetops and peaks may see gusts of 60 to 70 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 9 to 20
  percent on Sunday. Poor relative humidity recoveries overnight 
  in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-291800-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
1048 PM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT SUNDAY FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES 
503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

* WINDS...North 10 to 20 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 8 to 20
  percent on Sunday. Poor relative humidity recoveries overnight
  in the 25 to 45 percent range for the interior valleys. For the
  coastal regions, peak humidity recovery has passed and further
  drying is expected overnight.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ517-291800-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
1048 PM PDT Sat Oct 28 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT SUNDAY FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR ZONE 517...

* AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains 
  and Los Padres National Forest.

* WINDS...Northeast 5 to 15 mph with gusts up to 30 mph. Highest
  ridgetops and peaks may see gusts of 40 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 20
  percent on Sunday. Poor relative humidity recoveries overnight
  in the 15 to 35 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

420 
WWUS86 KMTR 291746
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
1046 AM PDT Sun Oct 29 2023

...CRITICAL FIRE WEATHER CONDITIONS NOW THROUGH SUNDAY...

.North-northeast winds continue across the ridges of the North
Bay, East Bay, Santa Cruz Mountains, and the Santa Lucia
Mountains. Offshore winds will gradually ease through Sunday 
evening. Despite easing winds, relative humidity values will 
remain critically low. The combination of lingering offshore flow
and low humidity will keep critical fire weather condition in 
place.

CAZ502-504-512-514-515-300000-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
1046 AM PDT Sun Oct 29 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 502,504,512,514,515...

* AFFECTED AREA...Fire Weather Zone 502 Marin Coastal Range, 
  Fire Weather Zone 504 North Bay Interior Mountains, Fire 
  Weather Zone 512 Santa Cruz Mountains, Fire Weather Zone 514 
  Eastern Santa Clara Hills and Fire Weather Zone 515 East Bay 
  Hills.

* WINDS...North 15 to 25 mph with gusts up to 45 mph. Highest 
  ridgetops and peaks may see gusts of 60 to 70 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 9 to 
  20 percent on Sunday. Poor relative humidity recoveries 
  overnight in the 20 to 40 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ503-505-506-509-510-300000-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
1046 AM PDT Sun Oct 29 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE
ZONES 503,505,506,509,510...

* AFFECTED AREA...Fire Weather Zone 503 Sonoma Coastal Range, 
  Fire Weather Zone 505 Coastal North Bay Including Point Reyes 
  National Seashore, Fire Weather Zone 506 North Bay Interior 
  Valleys, Fire Weather Zone 509 San Francisco Peninsula Coast 
  and Fire Weather Zone 510 East Bay Interior Valleys.

* WINDS...North 10 to 20 mph with gusts up to 35 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 8 to 20
  percent on Sunday. Poor relative humidity recoveries overnight
  in the 25 to 45 percent range for the interior valleys. 

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

CAZ517-300000-
/O.CON.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
1046 AM PDT Sun Oct 29 2023

...RED FLAG WARNING REMAINS IN EFFECT UNTIL 5 PM PDT THIS
AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR ZONE
517...

* AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains 
  and Los Padres National Forest.

* WINDS...Northeast 5 to 15 mph with gusts up to 30 mph. Highest 
  ridgetops and peaks may see gusts of 40 mph.

* RELATIVE HUMIDITY...Minimum relative humidity as low as 10 to 
  20 percent on Sunday. Poor relative humidity recoveries 
  overnight in the 15 to 35 percent range.

* IMPACTS...The combination of gusty winds and low humidity can 
  cause fire to rapidly grow in size and intensity. Outdoor 
  burning is not recommended.

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.

&&

$$

683 
WWUS86 KMTR 292359
RFWMTR

URGENT - FIRE WEATHER MESSAGE
National Weather Service San Francisco CA
459 PM PDT Sun Oct 29 2023

...RED FLAG WARNING EXPIRES AT 5PM, DRY CONDITIONS REMAIN...

.Offshore winds have shown signs of weakening, though humidities
remain low. With offshore winds expected to become light into the
night, criteria for a Red Flag Warning is no longer being met. 
However, even with light winds, humidities will remain critically 
low through the later part of the week. 


CAZ502-504-512-514-515-300100-
/O.EXP.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Marin Coastal Range-North Bay Interior Mountains-
Santa Cruz Mountains-Eastern Santa Clara Hills-East Bay Hills-
459 PM PDT Sun Oct 29 2023

...RED FLAG WARNING WILL EXPIRE AT 5 PM PDT THIS AFTERNOON FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES
502,504,512,514,515...

Breezy to strong offshore winds have begun to dissipate, with
gusts only up to around 20 mph being seen at the highest peaks at
this time. Winds are expected to continue to diminish into the 
night to become light to moderate. However, humidities will 
continue to remain low through the late week, so caution is urged 
to prevent any accidental ignitions.

$$

CAZ503-505-506-509-510-300100-
/O.EXP.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Sonoma Coastal Range-
Coastal North Bay Including Point Reyes National Seashore-
North Bay Interior Valleys-San Francisco Peninsula Coast-
East Bay Interior Valleys-
459 PM PDT Sun Oct 29 2023

...RED FLAG WARNING WILL EXPIRE AT 5 PM PDT THIS AFTERNOON FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE ZONES
503,505,506,509,510...

Breezy to strong offshore winds have begun to dissipate, with
gusts only up to around 20 mph being seen at the highest peaks at
this time. Winds are expected to continue to diminish into the 
night to become light to moderate. However, humidities will 
continue to remain low through the late week, so caution is urged 
to prevent any accidental ignitions.

$$

CAZ517-300100-
/O.EXP.KMTR.FW.W.0004.000000T0000Z-231030T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
459 PM PDT Sun Oct 29 2023

...RED FLAG WARNING WILL EXPIRE AT 5 PM PDT THIS AFTERNOON FOR
GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR ZONE 517...

Breezy to strong offshore winds have begun to dissipate, with
gusts only up to around 20 mph being seen at the highest peaks at
this time. Winds are expected to continue to diminish into the 
night to become light to moderate. However, humidities will 
continue to remain low through the late week, so caution is urged 
to prevent any accidental ignitions.

$$

Area Forecast Discussion
National Weather Service San Francisco CA
949 AM PDT Fri Oct 27 2023

...New AVIATION, MARINE...

.SYNOPSIS...
Issued at 126 AM PDT Fri Oct 27 2023

Cold overnight lows expected through Saturday morning with frost
possible within the North Bay valleys. Gusty offshore winds
develop this weekend with elevated fire weather conditions. Fire
Weather Watch in effect for the North Bay interior mountains, the
East Bay Hills, the Eastern Santa Clara Hills, and the Santa Cruz
Mountains Saturday morning through Sunday evening.

&&

.UPDATE...
Issued at 813 AM PDT Fri Oct 27 2023

It was a chilly morning for the North Bay interior valleys and
portions of the Bay Area. Temperatures dipped into the low to mid
30s this morning across the North Bay interior valleys and
received reports of frost on windshields. Tonight into Saturday
looks to be even cooler, and a Frost Advisory for the N Bay
valleys is in effect. Across the Bay Area, temperatures got colder
as well with SF Downtown dipping to 48 degrees, just a degree shy
from the daily low temperature record (see Climate section below
for more temperature records).

We continue to closely monitor the offshore wind setup for this
upcoming weekend, which will result in elevated fire weather
concerns. Stay tuned for upcoming forecast updates..

&&

.SHORT TERM...
(Today and tonight)
Issued at 126 AM PDT Fri Oct 27 2023

Water vapor imagery early this morning revealed mid-level moisture
approaching from the west in association with upper troughing and a
weak surface low. The low should gradually fill while remaining
offshore thus keeping and light precipitation chances well away from
the region. Meanwhile a positively tilted longwave trough will drop
down closer to our area from the north. This pattern will result in
benign weather across the area today with sunshine and some passing
high clouds at times. Temperatures will be on the cool side with
highs mostly in the 60s. Winds will be light and onshore during the
afternoon and evening.

Tonight should provide a decent radiational cooling setup. While
some high clouds may be around, a consensus of forecast models
suggest they should be waning as the night goes on. Surface winds
appear light and decoupled prior to sunrise, with decent overnight
humidity recoveries. Temperatures will drop into the 30s and 40s,
with the warmest readings along the coast and bays. Conditions
appear supportive of frost formation within the North Bay Valleys as
temperatures should drop into the mid to upper 30s. For this reason
hoisted a Frost Advisory for this area from late tonight into
Saturday morning. Now that we're getting into the cold season this
is a good reminder to protect people, pets, plants and pipes from
the cold.

&&

.LONG TERM...
(Saturday through Thursday)
Issued at 126 AM PDT Fri Oct 27 2023

This Weekend:

The forecast remains on track with a dry offshore wind event
anticipated this weekend. The synoptic picture is consistent with
troughing over the interior west (the "Inside Slider" setup) and a
backdoor front sweeping through our area. This pattern will enhance
the pressure gradient off the Sierra as strong surface high pressure
settles over the northern Rockies. A consensus of forecast models
and their ensembles (NAM, GFS, and GEFS) suggest the offshore
pressure gradient (WMC-SFO) will reach minus 13 to 15 mb between 06-
15Z Sunday, setting the stage for a multi-hour event. Placing
this in context, these pressure gradient values are consistent
with those previously observed during moderate to strong offshore
wind events in the Bay Area. We're now within range where the
higher resolution mesoscale models come into play, and they are
painting the same picture. Northeast winds developing initially to
our northeast early Saturday with the stronger winds pushing
southwest through the core of the Bay Area from late Saturday into
Sunday morning. These winds will transport very dry air into the
region resulting in poor Saturday morning humidity recoveries with
afternoon values likely in the 10-25 percent range for most of
the Bay Area on Sunday. This sets the stage for enhanced fire
weather conditions, with the greatest focus on the North Bay
Interior Mountains, the Marin Coastal Range, the East Bay and
Santa Clara Hills, and the Santa Cruz Mountains. Wind speeds of
35- 55 mph are expected for ridgetops, with some breeziness
perhaps making it into the neighboring valleys as well. Given
increased confidence in both strong sustained winds and gusts
decided to issue a Wind Advisory for the North Bay interior
mountains, the East Bay Hills, the Eastern Santa Clara Hills, and
the Santa Cruz Mountains from Saturday afternoon into Sunday. So
not only will there be strong winds to contend with, but the
combination of gusty winds and critically low humidity values
suggest that enhanced fire weather concerns are in play. A Fire
Weather Watch remains in effect for the previously mentioned
mountain areas from early Saturday morning through early Sunday
evening. For more details please see the fire weather discussion
appended below. A few safety tips to remember are:

* Properly dispose of cigarettes and matches
* Do not use a lawn mower or weeds or dry grass
* Avoid using equipment that creates sparks
* Make sure campfires are completely put out
* Make sure no vehicle parts drag on the ground, including towing
  chains
* Obey burn bans & only burn with a permit

Monday through Thursday:

A shortwave ridge aloft should set up over the region initially with
dry conditions and slightly warmer temperatures. A more progressive
and zonal pattern evolves by late week with shower chances possible

&&

.AVIATION...
(18Z TAFS)
Issued at 934 AM PDT Fri Oct 27 2023

High confidence in VFR prevailing through the TAF period as an
offshore flow regime sets up for the weekend. Low confidence in a
hint of low-to-mid level stratus moving across the Bay Area
overnight Friday into Saturday morning, though any stratus that
should form would be quickly eradicated by increasing dry
offshore flow Saturday morning. Generally light winds through
today with some breezy onshore flow to 15 kts in gap areas,
turning more northerly into Saturday as the offshore pattern sets
in.

Vicinity of SFO...VFR through the period. Gusty onshore flow 15-20
kts though the San Bruno gap Friday afternoon. The end of the TAF
period will see light winds turning more N-NE as offshore flow
increases.

SFO Bridge Approach...Similar to SFO.

Monterey Bay Terminals...VFR through the TAF period. Low
confidence in a hint of stratus moving through the area overnight
tonight into Saturday morning, though any stratus that does
develop would be quickly eradicated by increasing dry offshore
flow Saturday.

&&

.MARINE...
(Today through Wednesday)
Issued at 934 AM PDT Fri Oct 27 2023

Light to moderate northwest winds through today will turn more
northerly as a storm system moves into the Great Basin. Near the
coast, winds will be more northeasterly under the offshore flow
regime Saturday through the early week. Light northwest swell
exists in the background through the first half of the week at
around 8 to 10 seconds, while a longer period southwesterly swell
of about 3 feet at 17 to 19 seconds enters Saturday through the
rest of the period.

&&

.FIRE WEATHER...
Issued at 250 PM PDT Thu Oct 26 2023

Offshore wind setup slated for the weekend will bring elevated
fire weather conditions to the North Bay, East Bay hills, and the
Santa Cruz Mtns. Increasing confidence in the track of an upper
low through the Great Basin will cause a surface high pressure to
build across the interior regions Saturday. Ensemble guidance
advertising the SFO-WMC pressure gradient in the -12 to -14 mb
range during the time from about noon Saturday through noon
Sunday, which is approaching the 99th percentile. This set up
promotes widespread offshore flow with high confidence. Wind gusts
along ridgetops expected to be in the 35-45 mph range, with
moderate confidence that a few of the favored spots such as Mt.
St. Helena and Mt. Diablo could see gusts to 50 mph. Minimum RH
during the afternoons Saturday and Sunday will be in the 15-20%
range across much of the area as the downsloping offshore winds
increase. Overnight recoveries aren't much better between 25-45%.

The limiting factors with this event are related to the fuel
conditions and the degree of stability in the valleys. In regards
to the fuels, there is less concern in the more dense 100 and 1000
hour fuels as much of the moisture is still retained from recent
rains. Much more concern lies in the finer, more flashy fuels,
such as grasses and shrubbery. Stability presents some degree of
uncertainty to the wind forecast in valley areas. These areas are
still expected to be breezy through the weekend, but not as high
as their adjacent mountains and hills. If the valleys are able to
hold on to their moisture a little longer with weaker flow near
the surface, the atmosphere would remain largely decoupled and
the highest gusts would remain in the higher terrain. The worst
case scenario would be the stability completely eroding allowing
the highest gusts to mix down into the valley floors. We will be
keeping a close eye on this over the coming shifts and update the
forecast as needed.

&&

.CLIMATE...
Issued at 512 PM PDT Thu Oct 26 2023

Record low temperatures at the long term sites:

Station                 Oct 27th                Oct 28th

Santa Rosa              28 in 1919              28 in 1946
Kentfield               34 in 1919              34 in 1923, 1919
Napa                    34 in 1918              31 in 1946
Richmond                43 in 1984, 1970        41 in 1956
Livermore               30 in 1946              30 in 1946
San Francisco downtown  47 in 1984, 1908, 1893  46 in 1971
SFO Airport             42 in 1954, 1951        40 in 1954
Redwood City            39 in 1931              33 in 1946
Half Moon Bay           37 in 2022              37 in 1946
Oakland downtown        46 in 2010, 2004, 1975  44 in 1975
San Jose                37 in 1893              35 in 1946, 1894
Gilroy                  30 in 1967              30 in 1967
Salinas Airport         34 in 1931              32 in 1946
King City               30 in 1970, 1929        29 in 1984, 1970

&&

.MTR WATCHES/WARNINGS/ADVISORIES...
CA...Fire Weather Watch from late tonight through Sunday afternoon
     for CAZ502-504-512-514-515.

     Wind Advisory from 8 AM Saturday to 5 PM PDT Sunday for CAZ502-
     504-512-514-515.

     Frost Advisory from 1 AM to 10 AM PDT Saturday for CAZ506.

PZ...Small Craft Advisory from 3 PM this afternoon to 9 PM PDT this
     evening for PZZ535.

     Small Craft Advisory until 3 AM PDT Saturday for PZZ565.

&&

SHORT TERM...SPM
LONG TERM....SPM
AVIATION...Behringer
MARINE...Behringer

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