Alert archive / California / Frost Advisories in 2021
Frost Advisory 6, NWS San Francisco Bay Area, CA
NWS San Francisco Bay Area, CA issued this frost advisory at Nov 24, 2021, 2:49 PM PST for 7 counties in California. It took effect at Nov 25, 2021, 3:00 AM PST. It was in force for 6 hr.
The area
The counties it named.
The facts
- Issued
- Nov 24, 2021, 2:49 PM PST (22:49 UTC)
- In effect from
- Nov 25, 2021, 3:00 AM PST
- Expired
- Nov 25, 2021, 9:00 AM PST
- In force
- 6 hr
- Issued by
- NWS San Francisco Bay Area, CA
Counties Alameda County, CA, Contra Costa County, CA, Marin County, CA, Monterey County, CA, Napa County, CA, San Benito County, CA, Sonoma County, CA
The radar
The San Francisco radar (KMUX), 56 km from the middle of the area, began a volume at 22:49 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, 10.8 hours before the alert went out and 17 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
- 2520 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 70 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
022 WWUS76 KMTR 242249 NPWMTR URGENT - WEATHER MESSAGE National Weather Service San Francisco Bay Area 249 PM PST Wed Nov 24 2021 CAZ506-510-516-518-528-250800- /O.NEW.KMTR.FR.Y.0006.211125T1100Z-211125T1700Z/ North Bay Interior Valleys-East Bay Interior Valleys- Southern Salinas Valley/Arroyo Seco and Lake San Antonio- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- Northern Salinas Valley/Hollister Valley and Carmel Valley- Including the cities of Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato, Rohnert Park, Concord, Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, San Ramon, Greenfield, King City, and Salinas 249 PM PST Wed Nov 24 2021 ...FROST ADVISORY IN EFFECT FROM 3 AM TO 9 AM PST THURSDAY... * WHAT...Low temperatures for the interior valleys will be in low to mid 30s and will result in frost formation. * WHERE...North Bay Interior Valleys, East Bay Interior Valleys, Southern Salinas Valley/Arroyo Seco and Lake San Antonio, Mountains Of San Benito County and Interior Monterey County Including Pinnacles National Park and Northern Salinas Valley/Hollister Valley and Carmel Valley. * WHEN...From 3 AM to 9 AM PST Thursday. * IMPACTS...Frost could kill sensitive outdoor vegetation if left uncovered. * ADDITIONAL DETAILS...Please note that in mountain areas, valleys within the terrain could also see frosty conditions. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect animals and tender plants from the cold. && $$ For more information from the National Weather Service visit http://weather.gov/mtr
2 follow-up statements
424 WWUS76 KMTR 250746 NPWMTR URGENT - WEATHER MESSAGE National Weather Service San Francisco Bay Area 1146 PM PST Wed Nov 24 2021 CAZ506-510-516-518-528-251600- /O.CON.KMTR.FR.Y.0006.211125T1100Z-211125T1700Z/ North Bay Interior Valleys-East Bay Interior Valleys- Southern Salinas Valley/Arroyo Seco and Lake San Antonio- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- Northern Salinas Valley/Hollister Valley and Carmel Valley- Including the cities of Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato, Rohnert Park, Concord, Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, San Ramon, Greenfield, King City, and Salinas 1146 PM PST Wed Nov 24 2021 ...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 9 AM PST THURSDAY... * WHAT...Low temperatures for the interior valleys will be in the low to mid 30s and will result in frost formation. * WHERE...North Bay Interior Valleys, East Bay Interior Valleys, Southern Salinas Valley/Arroyo Seco and Lake San Antonio, Mountains Of San Benito County and Interior Monterey County Including Pinnacles National Park and Northern Salinas Valley/Hollister Valley and Carmel Valley. * WHEN...From 3 AM to 9 AM PST Thursday. * IMPACTS...Frost and freeze conditions will kill crops and other sensitive vegetation. Extended exposure to cold can cause hypothermia for animals and people. Vehicle windshields will be frosted. PRECAUTIONARY/PREPAREDNESS ACTIONS... Take steps now to protect tender plants from the cold. && $$ For more information from the National Weather Service visit http://weather.gov/mtr
334 WWUS76 KMTR 251651 NPWMTR URGENT - WEATHER MESSAGE National Weather Service San Francisco Bay Area 851 AM PST Thu Nov 25 2021 CAZ506-510-516-518-528-251800- /O.EXP.KMTR.FR.Y.0006.000000T0000Z-211125T1700Z/ North Bay Interior Valleys-East Bay Interior Valleys- Southern Salinas Valley/Arroyo Seco and Lake San Antonio- Mountains Of San Benito County And Interior Monterey County Including Pinnacles National Park- Northern Salinas Valley/Hollister Valley and Carmel Valley- Including the cities of Santa Rosa, South Santa Rosa, Napa, San Rafael, Petaluma, Novato, Rohnert Park, Concord, Antioch, Livermore, Walnut Creek, Pleasanton, Pittsburg, San Ramon, Greenfield, King City, and Salinas 851 AM PST Thu Nov 25 2021 ...FROST ADVISORY WILL EXPIRE AT 9 AM PST THIS MORNING... Temperatures will continue to rise through the day. A Frost Advisory is no longer needed and will expire at 9 AM. $$ For more information from the National Weather Service visit http://weather.gov/mtr
The office that day
Everything else NWS San Francisco Bay Area, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Nov 23, 9:22 PM PST | Small Craft Advisory | MTR | 12 hr | |
| Nov 24, 9:03 AM PST | Small Craft Advisory | MTR | 12 hr |
Nearby
Frost Advisories in California, 2021Every frost advisory 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.