Alert archive / California / Red Flag Warnings in 2019
Red Flag Warning 5, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this red flag warning at Oct 22, 2019, 9:27 AM PDT for 8 counties in California. It took effect at Oct 23, 2019, 12:00 PM PDT. It was in force for 28 hr. No storm report in the archive falls inside the area while it was in force.
The area
The counties it named.
The facts
- Issued
- Oct 22, 2019, 9:27 AM PDT (16:27 UTC)
- In effect from
- Oct 23, 2019, 12:00 PM PDT
- Expired
- Oct 24, 2019, 4:00 PM PDT
- In force
- 28 hr
- Issued by
- NWS San Francisco Bay Area, CA
Counties Alameda County, CA, Contra Costa County, CA, Marin County, CA, Napa County, CA, San Mateo County, CA, Santa Clara County, CA, Santa Cruz County, CA, Sonoma County, CA
The radar
The San Francisco radar (KMUX), 77 km from the middle of the area, began a volume at 16:30 UTC, the scan nearest the moment this went out.
Open the radar archive at this moment
The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.
The nearest sounding before it
Oakland, CA (KOAK), launched 12:00Z, 4.5 hours before the alert went out and 8 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 2608 m above ground
- 0-6 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- -80 m²/s²
- 0-3 km storm-relative helicity
- -46 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
305 WWUS86 KMTR 221627 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 927 AM PDT Tue Oct 22 2019 ...Red Flag warning for the North Bay, East Bay Hills/Valleys and Santa Cruz Mountains Wednesday afternoon into Thursday... .Warm and dry weather will develop by midday Wednesday. Strong north to northeast winds will then develop over the North Bay and spread southward over the East Bay and Santa Cruz Mountains Wednesday Night into Thursday. The winds will ease by Thursday afternoon but very low humidity will persist right through Friday. Another even stronger wind event is forecast Saturday Night into Sunday across the Bay Area that may bring another round of fire weather headlines. CAZ507-230400- /O.UPG.KMTR.FW.A.0003.191023T1900Z-191024T2300Z/ /O.NEW.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ North Bay Mountains- 927 AM PDT Tue Oct 22 2019 ...RED FLAG WARNING IN EFFECT FROM NOON WEDNESDAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY MOUNTAINS FOR FIRE WEATHER ZONE 507... The National Weather Service in San Francisco has issued a Red Flag Warning, which is in effect from noon Wednesday to 4 PM PDT Thursday. The Fire Weather Watch is no longer in effect. * WIND...North to northeast winds 15 to 25 mph with gusts 30 to 40 mph developing late Wednesday afternoon then peaking overnight into early Thursday morning. Locally higher gusts to 60 mph over the highest peaks. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoon through Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly the peaks and ridges in Napa and Sonoma County. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ511-230400- /O.UPG.KMTR.FW.A.0003.191024T0300Z-191024T2300Z/ /O.NEW.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Hills and the Diablo Range- 927 AM PDT Tue Oct 22 2019 ...RED FLAG WARNING IN EFFECT FROM 3 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE EAST BAY HILLS FOR FIRE WEATHER ZONE 511... The National Weather Service in San Francisco has issued a Red Flag Warning, which is in effect from 3 PM Wednesday to 4 PM PDT Thursday. The Fire Weather Watch is no longer in effect. * WIND...North to northeast winds 10 to 20 mph with gusts 30 to 40 mph. Winds developing late Wednesday afternoon then peaking during the overnight and early morning hours of Thursday. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoon through Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly Mt Diablo State Park, and gaps/passes. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ512-230400- /O.UPG.KMTR.FW.A.0003.191024T0300Z-191024T2300Z/ /O.NEW.KMTR.FW.W.0005.191024T0200Z-191024T2300Z/ Santa Cruz Mountains- 927 AM PDT Tue Oct 22 2019 ...RED FLAG WARNING IN EFFECT FROM 7 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE SANTA CRUZ MOUNTAINS FOR FIRE WEATHER ZONE 512... The National Weather Service in San Francisco has issued a Red Flag Warning, which is in effect from 7 PM Wednesday to 4 PM PDT Thursday. The Fire Weather Watch is no longer in effect. * WIND...North to northeast winds 10 to 20 mph with gusts to 35 mph. * HUMIDITY...Overnight humidity values 20 to 30 percent Wednesday night. Widespread minimum daytime humidity values Thursday in the teens. * HIGHEST THREAT...Higher terrain above 1000 feet. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ505-506-230400- /O.NEW.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys- 927 AM PDT Tue Oct 22 2019 ...RED FLAG WARNING IN EFFECT FROM NOON WEDNESDAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY VALLEYS AND COASTLINE FOR FIRE WEATHER ZONES 505 AND 506... The National Weather Service in San Francisco has issued a Red Flag Warning, which is in effect from noon Wednesday to 4 PM PDT Thursday. * AFFECTED AREA...Fire weather zones 505 and 506. This includes the North Bay Valleys and coastline including Highway 1 and Point Reyes National Seashore. * WIND...Dry east winds 10 to 20 mph with gusts to 35 mph along the Marin coast. Strongest winds overnight Wednesday into Thursday morning. * HUMIDITY...15 to 30 percent through the period with little or no nighttime humidity recovery * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ510-230400- /O.NEW.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Interior Valleys- 927 AM PDT Tue Oct 22 2019 ...RED FLAG WARNING IN EFFECT FROM 3 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE EAST BAY VALLEYS FOR FIRE WEATHER ZONE 510... The National Weather Service in San Francisco has issued a Red Flag Warning, which is in effect from 3 PM Wednesday to 4 PM PDT Thursday. * AFFECTED AREA...Fire weather zone 510. The East Bay Valleys. * WIND...Northeast winds 15 to 25 mph with gusts 35 mph. * HUMIDITY...12 to 28 percent with little or no recovery Wednesday Night into Thursday morning. * HIGHEST THREAT...Eastern Contra Costa county where strong winds from the Central Valley will filter into the East Bay interior valleys. * IMPACTS...any fires that develop will likely spread rapidly. 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. && $$
5 follow-up statements
697 WWUS86 KMTR 230338 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 838 PM PDT Tue Oct 22 2019 ...Red Flag warning for the North Bay, East Bay Hills/Valleys and Santa Cruz Mountains Wednesday afternoon into Thursday... .Warm and dry weather will develop by midday Wednesday. Strong north to northeast winds will then develop over the North Bay and spread southward over the East Bay and Santa Cruz Mountains Wednesday night into Thursday. The winds will ease by Thursday afternoon; however, very low humidity values will persist through Friday. Another even stronger wind event is forecast Saturday night into Sunday across the Bay Area that may bring another round of fire weather headlines. CAZ507-231300- /O.CON.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ North Bay Mountains- 838 PM PDT Tue Oct 22 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON WEDNESDAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY MOUNTAINS FOR FIRE WEATHER ZONE 507... * WIND...North to northeast winds 15 to 25 mph with gusts 30 to 40 mph developing late Wednesday afternoon then peaking overnight into early Thursday morning. Locally higher gusts to 60 mph over the highest peaks. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoon through Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly the peaks and ridges in Napa and Sonoma County. * IMPACTS...Any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ511-231300- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Hills and the Diablo Range- 838 PM PDT Tue Oct 22 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 3 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE EAST BAY HILLS FOR FIRE WEATHER ZONE 511... * WIND...North to northeast winds 10 to 20 mph with gusts 30 to 40 mph. Winds developing late Wednesday afternoon then peaking during the overnight and early morning hours of Thursday. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoon through Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly Mt Diablo State Park, and gaps/passes. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ505-506-231300- /O.CON.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys- 838 PM PDT Tue Oct 22 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON WEDNESDAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY VALLEYS AND COASTLINE FOR FIRE WEATHER ZONES 505 AND 506... * AFFECTED AREA...Fire weather zones 505 and 506. This includes the North Bay Valleys and coastline including Highway 1 and Point Reyes National Seashore. * WIND...Dry east winds 10 to 20 mph with gusts to 35 mph along the Marin coast. Strongest winds overnight Wednesday into Thursday morning. * HUMIDITY...15 to 30 percent through the period with little or no nighttime humidity recovery. * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ512-231300- /O.CON.KMTR.FW.W.0005.191024T0200Z-191024T2300Z/ Santa Cruz Mountains- 838 PM PDT Tue Oct 22 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 7 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE SANTA CRUZ MOUNTAINS FOR FIRE WEATHER ZONE 512... * WIND...North to northeast winds 10 to 20 mph with gusts to 35 mph. * HUMIDITY...Overnight humidity values 20 to 30 percent Wednesday night. Widespread minimum daytime humidity values Thursday in the teens. * HIGHEST THREAT...Higher terrain above 1000 feet. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ510-231300- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Interior Valleys- 838 PM PDT Tue Oct 22 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 3 PM WEDNESDAY TO 4 PM PDT THURSDAY FOR THE EAST BAY VALLEYS FOR FIRE WEATHER ZONE 510... * AFFECTED AREA...Fire weather zone 510. The East Bay Valleys. * WIND...Northeast winds 15 to 25 mph with gusts 35 mph. * HUMIDITY...12 to 28 percent with little or no recovery Wednesday night into Thursday morning. * HIGHEST THREAT...Eastern Contra Costa county where strong winds from the Central Valley will filter into the East Bay interior valleys. * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
953 WWUS86 KMTR 231125 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 425 AM PDT Wed Oct 23 2019 ...Red Flag warning for the North Bay, East Bay Hills/Valleys and Santa Cruz Mountains Wednesday afternoon into Thursday... .Warm and dry weather will develop by midday Wednesday. Strong north to northeast winds will then develop over the North Bay and spread southward over the East Bay and Santa Cruz Mountains Wednesday night into Thursday. The winds will ease by Thursday afternoon; however, very low humidity values will persist through Friday. Another even stronger wind event is forecast Saturday night into Sunday across the Bay Area that may bring another round of fire weather headlines. CAZ507-232300- /O.CON.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ North Bay Mountains- 425 AM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY MOUNTAINS FOR FIRE WEATHER ZONE 507... * WIND...North to northeast winds 15 to 25 mph with gusts 30 to 40 mph developing late Wednesday afternoon then peaking overnight into early Thursday morning. Locally higher gusts to 60 mph over the highest peaks. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoonthrough Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly the peaks and ridges in Napa and Sonoma County. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ511-232300- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Hills and the Diablo Range- 425 AM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO 4 PM PDT THURSDAY FOR THE EAST BAY HILLS FOR FIRE WEATHER ZONE 511... * WIND...North to northeast winds 10 to 20 mph with gusts 30 to 40 mph. Winds developing late Wednesday afternoon then peaking during the overnight and early morning hours of Thursday. * HUMIDITY...Humidity values 15 to 30 percent Wednesday afternoonthrough Thursday with no nighttime recovery. Further drying during the overnight hours with single digits by Thursday. * HIGHEST THREAT...Higher terrain, particularly Mt Diablo State Park, and gaps/passes. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ505-506-232300- /O.CON.KMTR.FW.W.0005.191023T1900Z-191024T2300Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys- 425 AM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM NOON TODAY TO 4 PM PDT THURSDAY FOR THE NORTH BAY VALLEYS AND COASTLINE FOR FIRE WEATHER ZONES 505 AND 506... * AFFECTED AREA...Fire weather zones 505 and 506. This includes the North Bay Valleys and coastline including Highway 1 and Point Reyes National Seashore. * WIND...Dry east winds 10 to 20 mph with gusts to 35 mph along the Marin coast. Strongest winds overnight Wednesday into Thursday morning. * HUMIDITY...15 to 30 percent through the period with little or no nighttime humidity recovery. * IMPACTS...any fires that develop will likely spread rapidly. 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. && $$ CAZ512-232300- /O.CON.KMTR.FW.W.0005.191024T0200Z-191024T2300Z/ Santa Cruz Mountains- 425 AM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 7 PM THIS EVENING TO 4 PM PDT THURSDAY FOR THE SANTA CRUZ MOUNTAINS FOR FIRE WEATHER ZONE 512... * WIND...North to northeast winds 10 to 20 mph with gusts to 35 mph. * HUMIDITY...Overnight humidity values 20 to 30 percent Wednesday night. Widespread minimum daytime humidity values Thursday in the teens. * HIGHEST THREAT...Higher terrain above 1000 feet. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ510-232300- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Interior Valleys- 425 AM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO 4 PM PDT THURSDAY FOR THE EAST BAY VALLEYS FOR FIRE WEATHER ZONE 510... * AFFECTED AREA...Fire weather zone 510. The East Bay Valleys. * WIND...Northeast winds 15 to 25 mph with gusts 35 mph. * HUMIDITY...12 to 28 percent with little or no recovery Wednesday night into Thursday morning. * HIGHEST THREAT...Eastern Contra Costa county where strong winds from the Central Valley will filter into the East Bay interior valleys. * IMPACTS...any fires that develop will likely spread rapidly. 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. && $$
792 WWUS86 KMTR 232148 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 248 PM PDT Wed Oct 23 2019 ...Red Flag warning for the North Bay, East Bay Hills/Valleys and Santa Cruz Mountains tonight through 4 pm Thursday... .Strong north to northeast winds and low humidity are developing over the North Bay and will spread southward across the East Bay and Santa Cruz Mountains overnight into Thursday. The winds will ease by Thursday afternoon; however, very low humidity values will persist through Friday. Another even stronger wind event is forecast Saturday night into Sunday across the Bay Area that may bring another round of fire weather headlines. CAZ507-241100- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ North Bay Mountains- 248 PM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THURSDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 507... * WIND...North to northeast winds 15 to 25 mph with gusts 30 to 40 mph this evening then peaking overnight into early Thursday morning. Locally higher gusts to 60 mph over the highest peaks. * HUMIDITY...Humidity values 15 to 30 percent overnight through Thursday with no nighttime recovery. Continued very dry Thursday night into Friday. * HIGHEST THREAT...Higher terrain, particularly the peaks and ridges in Napa and Sonoma County. * IMPACTS...Any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ511-241100- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Hills and the Diablo Range- 248 PM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THURSDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 511... * WIND...North to northeast winds 10 to 20 mph with gusts 35 to 45 mph. Winds peaking during the overnight and early morning hours of Thursday. * HUMIDITY...Humidity values 15 to 30 percent through Thursday with no nighttime recovery. Continued very low humidity Thursday night into Friday. * HIGHEST THREAT...Higher terrain, particularly Mt Diablo State Park, and gaps/passes. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ512-241100- /O.CON.KMTR.FW.W.0005.191024T0200Z-191024T2300Z/ Santa Cruz Mountains- 248 PM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT FROM 7 PM THIS EVENING TO 4 PM PDT THURSDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 512... * WIND...North to northeast winds 10 to 20 mph with gusts to 35 mph. * HUMIDITY...Overnight humidity values 20 to 30 percent Wednesday night. Widespread minimum daytime humidity values Thursday in the teens. * HIGHEST THREAT...Higher terrain above 1000 feet. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ505-506-241100- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys- 248 PM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THURSDAY FOR DRY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 505 AND 506... * AFFECTED AREA...Fire weather zones 505 and 506 which includes the North Bay Valleys and coastline including Pt Reyes National Seashore. * WIND...Dry east winds 10 to 20 mph with gusts to 35 mph along the Marin coast. Strongest winds overnight into Thursday morning. * HUMIDITY...15 to 30 percent through the period with little or no nighttime humidity recovery. * IMPACTS...any fires that develop will likely spread rapidly. 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. && $$ CAZ510-241100- /O.CON.KMTR.FW.W.0005.191023T2200Z-191024T2300Z/ East Bay Interior Valleys- 248 PM PDT Wed Oct 23 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THURSDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 510... * AFFECTED AREA...Fire weather zone 510, the East Bay interior valleys. * WIND...Northeast winds 15 to 25 mph with gusts 35 mph. * HUMIDITY...12 to 28 percent with little or no recovery overnight into Thursday morning. * HIGHEST THREAT...Eastern Contra Costa county where strong winds from the Central Valley will filter into the East Bay interior valleys. * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$
116 WWUS86 KMTR 241055 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 355 AM PDT Thu Oct 24 2019 ...Red Flag warning for the North Bay, East Bay Hills/Valleys and Santa Cruz Mountains tonight through 4 pm Thursday... .Strong north to northeast winds and low humidity will persist through early Thursday morning. The winds will ease by Thursday afternoon; however, very low humidity values will persist through Friday. Another even stronger wind event is forecast Saturday night into Sunday across the Bay Area that may bring another round of fire weather headlines. CAZ507-242300- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ North Bay Mountains- 355 AM PDT Thu Oct 24 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THIS AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 507... * WIND...North to northeast winds 10 to 20 mph with gusts 40 mph through early Thursday morning before gradually diminish through the afternoon. Locally higher gusts to 50 mph over the highest peaks. * HUMIDITY...Humidity values 15 to 30 percent overnight through Thursday with no nighttime recovery. Continued very dry Thursday night into Friday. * HIGHEST THREAT...Higher terrain, particularly the peaks and ridges in Napa and Sonoma County. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ511-242300- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ East Bay Hills and the Diablo Range- 355 AM PDT Thu Oct 24 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THIS AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 511... * WIND...North to northeast winds 10 to 20 mph with gusts 35 to 45 mph. Winds peaking during the overnight and early morning hours of Thursday. * HUMIDITY...Humidity values 15 to 30 percent through Thursday with no nighttime recovery. Continued very low humidity Thursday night into Friday. * HIGHEST THREAT...Higher terrain, particularly Mt Diablo State Park, and gaps/passes. * IMPACTS...Any fires that develop will likely spread rapidly. Outdoor burning is not recommended. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ512-242300- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ Santa Cruz Mountains- 355 AM PDT Thu Oct 24 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THIS AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 512... * WIND...North to northeast winds 10 to 20 mph with gusts to 35 mph. * HUMIDITY...Overnight humidity values 20 to 30 percent Wednesday night. Widespread minimum daytime humidity values Thursday in the teens. * HIGHEST THREAT...Higher terrain above 1000 feet. * IMPACTS...Any fires that develop will likely spread rapidly. 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. && $$ CAZ505-506-242300- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys- 355 AM PDT Thu Oct 24 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THIS AFTERNOON FOR DRY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONES 505 AND 506... * AFFECTED AREA...Fire weather zones 505 and 506 which includes the North Bay Valleys and coastline including Pt Reyes National Seashore. * WIND...Dry east winds 10 to 20 mph with gusts to 25 mph along the Marin coast. Strongest winds overnight into Thursday morning. * HUMIDITY...15 to 30 percent through the period with little or no nighttime humidity recovery. * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Red Flag Warning means that critical fire weather conditions are either occurring now...or will shortly. A combination of strong winds...low relative humidity...and warm temperatures can contribute to extreme fire behavior. && $$ CAZ510-242300- /O.CON.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ East Bay Interior Valleys- 355 AM PDT Thu Oct 24 2019 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 4 PM PDT THIS AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR FIRE WEATHER ZONE 510... * AFFECTED AREA...Fire weather zone 510, the East Bay interior valleys. * WIND...Northeast winds 15 to 25 mph with gusts 35 mph. * HUMIDITY...12 to 28 percent with little or no recovery overnight into Thursday morning. * HIGHEST THREAT...Eastern Contra Costa county where strong winds from the Central Valley will filter into the East Bay interior valleys. * IMPACTS...any fires that develop will likely spread rapidly. 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. && $$
514 WWUS86 KMTR 242303 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 403 PM PDT Thu Oct 24 2019 ...Fire Weather Watch Saturday night through Monday morning for dangerously strong offshore winds... .Another offshore wind event will develop Saturday Night into Sunday. This event looks to be the strongest of this year and since the 2017 wine country fires. Strong northeast winds will only slowly ease later Sunday and persist right through Monday morning. This will be a long duration and extreme wind event. CAZ505>507-510-511-251215- /O.EXP.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ /O.NEW.KMTR.FW.A.0004.191027T0300Z-191028T1800Z/ Coastal North Bay Including Point Reyes National Seashore- North Bay Interior Valleys-North Bay Mountains- East Bay Interior Valleys-East Bay Hills and the Diablo Range- 403 PM PDT Thu Oct 24 2019 ...FIRE WEATHER WATCH IN EFFECT FROM SATURDAY EVENING THROUGH MONDAY MORNING FOR STRONG OFFSHORE WINDS FOR FIRE WEATHER ZONES 505, 506, 507, 510, AND 511... ...RED FLAG WARNING WILL EXPIRE AT 4 PM PDT THIS AFTERNOON FOR FIRE WEATHER ZONES 505, 506, 507, 510, AND 511... The National Weather Service in San Francisco has issued a Fire Weather Watch, which is in effect from Saturday evening through Monday morning. * WIND...Northeast winds 15 to 30 mph with frequent gusts 45 to 55 mph and local gusts 65 to 75 mph wind prone peaks like Mt Saint Helena and Mt Diablo. Winds peaking overnight Saturday into early Sunday morning before slowly decreasing Sunday afternoon. * HUMIDITY...Lowering 15 to 30 percent by Sunday afternoon. * IMPACTS...Any fires that develop will likely spread rapidly. * TIMING....Strongest winds late Saturday night into Sunday morning but moderate winds lasting through Monday morning. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$ CAZ512-251215- /O.EXP.KMTR.FW.W.0005.000000T0000Z-191024T2300Z/ /O.NEW.KMTR.FW.A.0004.191027T1000Z-191028T1800Z/ Santa Cruz Mountains- 403 PM PDT Thu Oct 24 2019 ...FIRE WEATHER WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING FOR STRONG OFFSHORE WINDS FOR FIRE WEATHER ZONE 512... ...RED FLAG WARNING WILL EXPIRE AT 4 PM PDT THIS AFTERNOON FOR FIRE WEATHER ZONE 512... The National Weather Service in San Francisco has issued a Fire Weather Watch, which is in effect from late Saturday night through Monday morning. * WINDS...Northeast winds 15 to 30 mph with gusts 45 mph late Saturday Night into Sunday. * HUMIDITY...Lowering 25 to 35 percent by Sunday afternoon. * HIGHEST THREAT...Santa Cruz mountains above 1500 feet including locations along Highway 9 and 92. * IMPACTS...Any fires that develop will likely spread rapidly * TIMING...Late Saturday night into Sunday morning with winds only slowly decreasing Sunday afternoon but remaining moderate into Monday morning. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$ CAZ509-251215- /O.NEW.KMTR.FW.A.0004.191027T1000Z-191028T1800Z/ San Francisco Peninsula Coast- 403 PM PDT Thu Oct 24 2019 ...FIRE WEATHER WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH MONDAY MORNING FOR COASTAL SAN MATEO COUNTY FOR FIRE WEATHER ZONE 509... The National Weather Service in San Francisco has issued a Fire Weather Watch, which is in effect from late Saturday night through Monday morning. * AFFECTED AREA...Fire weather zone 509. Coastal San Mateo County. * WIND...Northeast to East winds 15 to 30 mph with gusts 50 mph early Sunday morning. * HUMIDITY...Lowering 30-40 percent Sunday afternoon. * HIGHEST THREAT...Highway 1 corridor from south of Pacifica to near Davenport including Half Moon Bay and coastal areas east of Highway 1 * IMPACTS...any fires that develop will likely spread rapidly. PRECAUTIONARY/PREPAREDNESS ACTIONS... A Fire Weather Watch means that critical fire weather conditions are forecast to occur. Listen for later forecasts and possible Red Flag Warnings. && $$
What forecasters said that day
The local office's own words before this red flag warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS San Francisco Bay Area, CA wrote its last area forecast discussion before this red flag warning went out at Oct 22, 4:45 AM PDT, 4 hours 42 minutes earlier.
Area forecast discussion, Oct 22, 4:45 AM PDT, 4 hours 42 minutes before
Area Forecast Discussion
National Weather Service San Francisco Bay Area
445 AM PDT Tue Oct 22 2019
.SYNOPSIS...A warming and drying trend will continue through
the week as high pressure strengthens over California. Offshore
flow will continue through midweek and strengthen Wednesday night
into Thursday morning. This will result in warm temperatures
reaching all the way to the coast, with the warmest temperatures
expected on Thursday. Locally gusty offshore winds are likely at
times in the hills, especially in the North Bay Hills on Wednesday
night. In the longer range, cooling is forecast during the
upcoming weekend, although another round of dry offshore winds
is possible by late in the weekend and into early next week.
&&
.DISCUSSION...as of 04:05 AM PDT Tuesday...The overall impacts
message over the next few days has not changed much with this
forecast update. Simply put, ridge of high pressure will bring a
warming and drying trend to the region, but most importantly
elevate fire weather concerns to critical levels with gusty
offshore flow.
Current longwave pattern at 500mb shows a solid ridge of high
pressure anchored over the EPac. The ridge is still on track to
gradually build and drift eastward over the next two days. At the
surface, high pressure will also build across the PacNW and
eventually the Great Basin. This pattern began to take shape on
Monday with temperatures well above normal for this time of year.
Temperatures were so warm that a few stations set daily record
maximum temperatures for Oct 21. Additionally, the SFO-WMC did
briefly ramp up to 8.4 mb, which led to gusty winds in the
hills early Monday night. Mt Saint Helena maxed out at close to
50 mph. Winds have diminished slightly, but still remain breezy to
gusty in the hills. It also goes with out saying, these stronger
NE winds area rather dry with relative humidity in the 30-40%
range. These conditions are only setting the stage for a more
critical timeframe Wednesday night with stronger winds and lower
relative humidity, more on that later.
Based on what happened yesterday, building ridge, persistent
offshore flow, model trends - bumped up max temperatures for
Tuesday. Highs will generally be in the 70s and mid 80s at the
coast and 80s to lower 90s inland - or about 10-15 degrees above
normal. Daytime temperatures will hold steady on Wednesday before
rebounding on Thursday with the strongest offshore flow.
Temperatures on Thursday will likely be the warmest of the week
with highs in the 80s at the coast and upper 80s to mid 90s
interior. Friday was low confidence on max temps, but latest
guidance suggest another day of hot weather with lingering
offshore flow. Cooling trend finally develop over the weekend and
more so next week. Thermal belts will be in full effect the next
few nights with overnight lows mild in the hills due to offshore
flow.
Speaking of offshore flow there will be some ebb and flow of the
offshore pressure gradient strength the next few days. None the
less, the period of strongest offshore flow in the short term is still
focused on Wednesday night into Thursday morning. Models have been
rather consistent with hitting the North Bay Mts with the highest
winds. Local gusts up to 60 mph still seem plausible. East Bay
Hills will see weaker winds, but a gust up to 40 mph still seems
like a possibility. The same can be said for the Santa Cruz Mts
with gusts up to 30 mph. The set up definitely keeps the wind
threat more elevated in the hills and less in the valleys, but the
occasional gust in the valley could happen. Winds ease through the
day on Thursday and more so on Friday as the offshore flow
gradient weakens. The weakening gradient is a result of shifting
high pressure and a trough digging into the Pac NW Friday.
For several days now another offshore flow wind event has been
advertised on Sunday. The details, timing and strength, have
varied from model to model and run to run. However, one thing that
has stayed the same is another round of offshore flow. Latest 00Z
models are still very robust with some suggesting the Sunday
offshore flow set up could be stronger than Wednesday night. For
now, will have another strong offshore flow event, focused on the
North Bay again, but not going overboard on the potential just
yet.
For specific fire weather details see below.
&&
.AVIATION...as of 4:45 AM PDT Tuesday...Light north to
northeasterly flow will maintain predominantly clear skies over
area terminals through the forecast period. Slightly stronger
winds are expected through the afternoon and evening hours.
Vicinity of KSFO...VFR.
SFO Bridge Approach...Similar to KSFO.
Monterey Bay Terminals...VFR.
&&
.FIRE WEATHER...As of 4:05 AM PDT Tuesday...Fire Weather forecast
remains on track. Near critical fire weather conditions will
exist between now and early Wednesday with periods of gusty
offshore winds, lowering relative humidity and warming
temperatures. By Wednesday afternoon however the the offshore
gradient begins to increase resulting in increasing winds across
the North Bay Mountains. Winds will gradually increase over the
East Bay Hills and Santa Cruz Mountains Wednesday night and early
Thursday morning. As the winds increase, relative humidity will
gradually decrease with poor humidity recovery Wednesday night.
Therefore the Fire Weather Watch remains valid initially over the
North Bay Mountains Wednesday afternoon and then East Bay
Hills/Santa Cruz Mts Wednesday night. Relative humidity really
plummets during the day on Thursday despite some weakening winds.
Given very low RH and another day of hot temperatures decided to
keep the watch through peaking heating on Thursday. After
coordinating with neighboring forecast offices will let day shift
convert the Watch to a Red Flag Warning after morning coordination
calls have been completed with fire agencies and fire partners.
Do want to emphasize this is not an extreme event. It is fall and
the Bay Area typically sees offshore flow events like this.
Now for round two - as mentioned above models have been suggesting
another and potentially stronger offshore flow event over the
weekend. Peak for the second would likely be Saturday night and
Sunday morning. If the forecast stays on track additional fire
watches/warnings will likely be issued. It's just one model run,
but if the 00z GFS would verify the SFO-WMC gradient is greater
than 20 mb. Needless to say stay tuned...
&&
.MARINE...as of 2:52 AM PDT Tuesday...High pressure ridging over
the Pacific Northwest will produce moderate northerly winds across
the coastal waters through midweek. Strongest winds are expected
across the northern outer waters. As high pressure builds in over
the Great Basin during the second half of the week, a thermal
trough will develop along the coast. This will result in light
offshore flow across the coastal waters. A moderate northwest
swell will continue through midweek.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.Tday...SCA...Pt Arena to Pigeon Pt 10-60 nm
SCA...Pt Pinos to Pt Piedras Blancas 0-10 nm from 5 PM
SCA...Pigeon Pt to Pt Piedras Blancas 10-60 nm from 5 PM
SCA...Pt Arena to Pt Reyes 0-10 nm from 3 PM
&&
PUBLIC FORECAST: MM
AVIATION: CW
MARINE: CW
FIRE WEATHER: MM
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www.youtube.com/nwsbayareaThe office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Oct 21, 9:45 PM PDT | Small Craft Advisory | MTR | 43 hr |
Nearby
Red Flag Warnings in California, 2019Every red flag warning in 2019
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.