Alert archive / California / Red Flag Warnings in 2021
Red Flag Warning 1, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this red flag warning at Jan 18, 2021, 9:52 AM PST for Monterey County, San Benito County, California. It took effect at Jan 18, 2021, 7:00 PM PST. It was in force for 20 hr. 4 reports came from inside the area while it was in force.
The area
The counties it named, with what was reported inside it.
The facts
- Issued
- Jan 18, 2021, 9:52 AM PST (17:52 UTC)
- In effect from
- Jan 18, 2021, 7:00 PM PST
- Expired
- Jan 19, 2021, 3:00 PM PST
- In force
- 20 hr
- Issued by
- NWS San Francisco Bay Area, CA
Counties Monterey County, CA, San Benito County, CA
The radar
The San Francisco radar (KMUX), 103 km from the middle of the area, began a volume at 17:54 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.
What was reported inside it
| Time | Report | Where | Remark |
|---|---|---|---|
| Jan 19, 7:50 AM PST | NON-TSTM WND DMG | 4 Se Prunedale, CA | TREE DOWN BLOCKING BOTH LANES ON OLD STAGE RD AND HERBERT RD. |
| Jan 19, 9:00 AM PST | NON-TSTM WND DMG | 7 Ese Hollister, CA | LARGE TREE DOWN IN THE MIDDLE OF THE ROAD AT SANTA ANA VALLEY RD AND JOHN SMITH RD. |
| Jan 19, 9:15 AM PST | NON-TSTM WND DMG | 2 E Las Lomas, CA | TREE DOWN IN ROADWAY ON SAN MIGUEL CANYON ROAD. |
| Jan 19, 9:24 AM PST | NON-TSTM WND DMG | 1 Nne Prunedale, CA | TREE DOWN IN ROADWAY ON TUSTIN ROAD. |
Local storm reports filed while the alert was in force, from inside its polygon or its counties.
The nearest sounding before it
Oakland, CA (KOAK), launched 12:00Z, 5.9 hours before the alert went out and 171 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
- 2035 m above ground
- 0-6 km bulk shear
- 7 kt
- 0-1 km storm-relative helicity
- -158 m²/s²
- 0-3 km storm-relative helicity
- -74 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
116 WWUS86 KMTR 181752 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 952 AM PST Mon Jan 18 2021 ...Offshore wind event expected Monday evening into Tuesday... .Northeast winds will strengthen after sunset on Monday evening across the higher peaks of the Santa Lucia Range and Southern Gabilan Range, then increase further overnight into Tuesday morning and mix down to lower elevations. The airmass, which will become unseasonably dry by Monday afternoon will dry out further on Monday night. Strongest winds are expected midnight through just before daybreak on Tuesday with winds forecast to gust up to 50 mph, and locally higher over highest peaks. Winds will then gradually diminish during the day Tuesday, but remain gusty into Tuesday night on the west side of the Santa Lucias above Big Sur. CAZ517-518-190615- /O.UPG.KMTR.FW.A.0001.210119T0300Z-210119T2300Z/ /O.NEW.KMTR.FW.W.0001.210119T0300Z-210119T2300Z/ Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 952 AM PST Mon Jan 18 2021 ...RED FLAG WARNING IN EFFECT FROM 7 PM THIS EVENING TO 3 PM PST TUESDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR THE SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST AS WELL AS THE MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY The National Weather Service in San Francisco has issued a Red Flag Warning for gusty winds and low humidity, which is in effect from 7 PM this evening to 3 PM PST Tuesday. The Fire Weather Watch is no longer in effect. * AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains and Los Padres National Forest and Fire Weather Zone 518 Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park. * TIMING...Winds will begin to increase around sunset on Monday and continue to increase through Monday night. The strongest winds will occur midnight through daybreak Tuesday. Winds will begin to gradually diminish through Tuesday afternoon. * WINDS...North to Northeast winds 15 to 30 mph with frequent gusts of 40 to 50 mph. Local gusts over 50 mph for some of the higher peaks along the Santa Lucia Mountains and the Mountains of San Benito County. * RELATIVE HUMIDITY...Humidity will drop to 20-30 percent by Monday afternoon and then drop into the teens on Monday night when offshore winds increase. After sunrise Tuesday expect more widespread low teens across Southern Monterey County and 20- 25% across the Mountains of San Benito County. * IMPACTS...Any new starts aligned with wind will likely show moderate to rapid growth. Strong winds could cause power outages as well as downed trees and limbs. 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. && $$
3 follow-up statements
802 WWUS86 KMTR 190536 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 936 PM PST Mon Jan 18 2021 ...Offshore wind event expected Monday evening into Tuesday... .Northeast winds will strengthen by late Monday evening across the higher peaks of the Santa Lucia Range and Southern Gabilan Range, then and mix down to lower elevations by late Monday night. The airmass will remain unseasonably dry through Tuesday, with no overnight recovery expected Monday night. Strongest winds are expected from midnight Monday night through about daybreak on Tuesday when winds are forecast to gust as high as 50 mph, and locally higher over highest peaks. Winds will then gradually diminish during the day Tuesday, but remain gusty into Tuesday night on the west side of the Santa Lucias above Big Sur. CAZ517-518-191400- /O.CON.KMTR.FW.W.0001.000000T0000Z-210119T2300Z/ Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 936 PM PST Mon Jan 18 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 3 PM PST TUESDAY FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR THE SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST AS WELL AS THE MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY... * AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains and Los Padres National Forest and Fire Weather Zone 518 Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park. * TIMING...Winds will begin to increase around sunset on Monday and continue to increase through Monday night. The strongest winds will occur midnight through daybreak Tuesday. Winds will begin to gradually diminish through Tuesday afternoon. * WINDS...North to Northeast winds 15 to 30 mph with frequent gusts of 40 to 50 mph. Local gusts over 50 mph for some of the higher peaks along the Santa Lucia Mountains and the Mountains of San Benito County. * RELATIVE HUMIDITY...Humidity will remain as low as the teens on Monday night when offshore winds increase. After sunrise Tuesday expect more widespread low teens across Southern Monterey County and 20-25% across the Mountains of San Benito County. * IMPACTS...Any new starts aligned with the strong winds will likely show moderate to rapid growth. Strong winds could cause power outages as well as downed trees and limbs. 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. && $$
468 WWUS86 KMTR 191136 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 336 AM PST Tue Jan 19 2021 ...STRONG OFFSHORE WINDS AND CRITICALLY LOW HUMIDITY TO PERSIST THROUGH TUESDAY AFTERNOON... .Strong and gusty northeast winds will persist across the higher peaks of the Santa Lucia Range and Southern Gabilan Range, locally mixing down to lower elevations through Tuesday morning. These winds and critically dry conditions combined with unseasonably dry fuels will produce critical fire weather conditions through Tuesday afternoon. Winds will then gradually diminish Tuesday afternoon, but remain gusty into Tuesday night on the west side of the Santa Lucias above Big Sur. CAZ517-518-192300- /O.CON.KMTR.FW.W.0001.000000T0000Z-210119T2300Z/ Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 336 AM PST Tue Jan 19 2021 ...RED FLAG WARNING REMAINS IN EFFECT UNTIL 3 PM PST THIS AFTERNOON FOR GUSTY OFFSHORE WINDS AND LOW HUMIDITY FOR THE SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST AS WELL AS THE MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY... * AFFECTED AREA...Fire Weather Zone 517 Santa Lucia Mountains and Los Padres National Forest and Fire Weather Zone 518 Mountains of San Benito County and Interior Monterey County Including Pinnacles National Park. * TIMING...Through Tuesday afternoon. * WINDS...North to northeast winds 15 to 30 mph with frequent gusts of 40 to 50 mph. Local gusts greater than 50 mph for some of the higher peaks along the Santa Lucia Mountains and the mountains of San Benito County. * RELATIVE HUMIDITY...Teens across southern Monterey County and 20-25% across the mountains of San Benito County. * IMPACTS...Any new starts aligned with the strong winds will likely show moderate to rapid growth. Strong winds could cause power outages as well as downed trees and limbs. 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. && $$
981 WWUS86 KMTR 192259 RFWMTR URGENT - FIRE WEATHER MESSAGE National Weather Service San Francisco CA 259 PM PST Tue Jan 19 2021 ...RED FLAG WARNING BEING ALLOWED TO EXPIRE AT 3 PM PST THIS AFTERNOON FOR THE SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST AS WELL AS THE MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY... CAZ517-518-200000- /O.EXP.KMTR.FW.W.0001.000000T0000Z-210119T2300Z/ Santa Lucia Mountains and Los Padres National Forest- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- 259 PM PST Tue Jan 19 2021 ...RED FLAG WARNING WILL EXPIRE AT 3 PM PST THIS AFTERNOON FOR THE SANTA LUCIA MOUNTAINS AND LOS PADRES NATIONAL FOREST AS WELL AS THE MOUNTAINS OF SAN BENITO COUNTY AND INTERIOR MONTEREY COUNTY... Dry and locally breezy conditions will continue but no longer meet Red Flag Warning criteria. $$
Nearby
Red Flag Warnings in California, 2021Every red flag warning in 2021
Sources
The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.