Alert archive / California / Freeze Warnings in 2021

Freeze Warning 3, NWS San Francisco Bay Area, CA

December 11, 2021Monterey County, San Benito County, California

NWS San Francisco Bay Area, CA issued this freeze warning at Dec 11, 2021, 5:35 PM PST for Monterey County, San Benito County, California. It took effect at Dec 12, 2021, 12:00 AM PST. It was in force for 8 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
Dec 11, 2021, 5:35 PM PST (01:35 UTC)
In effect from
Dec 12, 2021, 12:00 AM PST
Expired
Dec 12, 2021, 8:00 AM PST
In force
8 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 01:33 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 00:00Z, 1.6 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.

Skew-T log-pSkew-T log-p diagram, Oakland, CA at 00:00Z on 2021-12-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Oakland, CA at 00:00Z on 2021-12-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1555 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
121 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

308 
WWUS76 KMTR 120135
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
535 PM PST Sat Dec 11 2021

CAZ516-518-121530-
/O.NEW.KMTR.FZ.W.0003.211212T0800Z-211212T1600Z/
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-
Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park-
Including the cities of Greenfield and King City
535 PM PST Sat Dec 11 2021

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM PST
SUNDAY...
...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...For the Freeze Warning, sub-freezing temperatures as 
  low as 33 expected. For the Wind Advisory, south winds 25 to 
  35 mph with gusts up to 55 mph expected.

* WHERE...Southern Salinas Valley/Arroyo Seco and Lake San 
  Antonio and Mountains Of San Benito County and Interior 
  Monterey County Including Pinnacles National Park.

* WHEN...For the Freeze Warning, from midnight tonight to 8 AM 
  PST Sunday. For the Wind Advisory, from 1 AM to 4 PM PST 
  Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result. Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

CAZ006-508>513-529-121530-
/O.CON.KMTR.WI.Y.0014.211213T0000Z-211213T1500Z/
San Francisco-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-
Santa Clara Valley Including San Jose-Northern Monterey Bay-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, Pacifica, Concord, Antioch, Livermore, 
Walnut Creek, Pleasanton, Pittsburg, San Ramon, Blackhawk, 
Scotts Valley, Boulder Creek, Day Valley, San Jose, Santa Cruz, 
Watsonville, and Live Oak
535 PM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 4 PM SUNDAY TO 7 AM PST
MONDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 55 mph 
  expected.

* WHERE...Portions of northern California.

* WHEN...From 4 PM Sunday to 7 AM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ517-528-530-121530-
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Southern Monterey Bay and Big Sur Coast-
Including the cities of Salinas, Seaside, Monterey, and Marina
535 PM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 60 mph 
  expected.

* WHERE...Santa Lucia Mountains and Los Padres National Forest, 
  Southern Monterey Bay and Big Sur Coast and Northern Salinas 
  Valley/Hollister Valley and Carmel Valley.

* WHEN...From 1 AM to 4 PM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr
3 follow-up statements
677 
WWUS76 KMTR 120622
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
1022 PM PST Sat Dec 11 2021

CAZ516-518-121600-
/O.CON.KMTR.FZ.W.0003.211212T0800Z-211212T1600Z/
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-
Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park-
Including the cities of Greenfield and King City
1022 PM PST Sat Dec 11 2021

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM
PST SUNDAY...
...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...For the Freeze Warning, sub-freezing temperatures as low
  as 23 expected. For the Wind Advisory, south winds 25 to 35 mph
  with gusts up to 55 mph expected.

* WHERE...Mountains Of San Benito County and Interior Monterey 
  County Including Pinnacles National Park and Southern Salinas 
  Valley/Arroyo Seco and Lake San Antonio.

* WHEN...For the Freeze Warning, from midnight tonight to 8 AM 
  PST Sunday. For the Wind Advisory, from 1 AM to 4 PM PST 
  Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result. Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

CAZ006-508>513-529-121600-
/O.CON.KMTR.WI.Y.0014.211213T0000Z-211213T1500Z/
San Francisco-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-
Santa Clara Valley Including San Jose-Northern Monterey Bay-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, Pacifica, Concord, Antioch, Livermore, 
Walnut Creek, Pleasanton, Pittsburg, San Ramon, Blackhawk, 
Scotts Valley, Boulder Creek, Day Valley, San Jose, Santa Cruz, 
Watsonville, and Live Oak
1022 PM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 4 PM SUNDAY TO 7 AM PST
MONDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 55 mph 
  expected.

* WHERE...Portions of northern California.

* WHEN...From 4 PM Sunday to 7 AM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ517-528-530-121600-
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Southern Monterey Bay and Big Sur Coast-
Including the cities of Salinas, Seaside, Monterey, and Marina
1022 PM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 60 mph 
  expected.

* WHERE...Santa Lucia Mountains and Los Padres National Forest, 
  Southern Monterey Bay and Big Sur Coast and Northern Salinas 
  Valley/Hollister Valley and Carmel Valley.

* WHEN...From 1 AM to 4 PM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. Tree
  limbs could be blown down and a few power outages may result.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr
377 
WWUS76 KMTR 121127
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
327 AM PST Sun Dec 12 2021

CAZ516-518-121930-
/O.CON.KMTR.FZ.W.0003.000000T0000Z-211212T1600Z/
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-
Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park-
Including the cities of Greenfield and King City
327 AM PST Sun Dec 12 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM PST THIS MORNING...
...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...For the Freeze Warning, sub-freezing temperatures as 
  low as 23 expected. For the Wind Advisory, south winds 25 to 
  35 mph with gusts up to 55 mph expected.

* WHERE...Mountains Of San Benito County and Interior Monterey 
  County Including Pinnacles National Park and Southern Salinas 
  Valley/Arroyo Seco and Lake San Antonio.

* WHEN...For the Freeze Warning, from midnight tonight to 8 AM 
  PST Sunday. For the Wind Advisory, from 1 AM to 4 PM PST 
  Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result. Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

Take steps now to protect tender plants from the cold. To prevent
freezing and possible bursting of outdoor water pipes they should
be wrapped, drained, or allowed to drip slowly. Those that have
in-ground sprinkler systems should drain them and cover above-
ground pipes to protect them from freezing.

&&

$$

CAZ006-508>513-529-121930-
/O.CON.KMTR.WI.Y.0014.211213T0000Z-211213T1500Z/
San Francisco-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-
Santa Clara Valley Including San Jose-Northern Monterey Bay-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, Pacifica, Concord, Antioch, Livermore, 
Walnut Creek, Pleasanton, Pittsburg, San Ramon, Blackhawk, 
Scotts Valley, Boulder Creek, Day Valley, San Jose, Santa Cruz, 
Watsonville, and Live Oak
327 AM PST Sun Dec 12 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO
7 AM PST MONDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 55 mph 
  expected.

* WHERE...Portions of northern California.

* WHEN...From 4 PM Sunday to 7 AM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ517-528-530-121930-
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Southern Monterey Bay and Big Sur Coast-
Including the cities of Salinas, Seaside, Monterey, and Marina
327 AM PST Sun Dec 12 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 60 mph 
  expected.

* WHERE...Santa Lucia Mountains and Los Padres National Forest, 
  Southern Monterey Bay and Big Sur Coast and Northern Salinas 
  Valley/Hollister Valley and Carmel Valley.

* WHEN...From 1 AM to 4 PM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

For more information from the National Weather Service visit
http://weather.gov/mtr
426 
WWUS76 KMTR 121555
NPWMTR

URGENT - WEATHER MESSAGE
National Weather Service San Francisco Bay Area
755 AM PST Sun Dec 12 2021

CAZ516-518-130700-
/O.EXP.KMTR.FZ.W.0003.000000T0000Z-211212T1600Z/
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Southern Salinas Valley/Arroyo Seco and Lake San Antonio-
Mountains Of San Benito County And Interior Monterey County
Including Pinnacles National Park-
Including the cities of Greenfield and King City
755 AM PST Sun Dec 12 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...
...FREEZE WARNING WILL EXPIRE AT 8 AM PST THIS MORNING...

* WHAT...South winds 25 to 35 mph with gusts up to 55 mph 
  expected.

* WHERE...Mountains Of San Benito County and Interior Monterey 
  County Including Pinnacles National Park and Southern Salinas 
  Valley/Arroyo Seco and Lake San Antonio.

* WHEN...From 1 AM to 4 PM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ006-508>513-529-130700-
/O.CON.KMTR.WI.Y.0014.211213T0000Z-211213T1500Z/
San Francisco-San Francisco Bay Shoreline-
San Francisco Peninsula Coast-East Bay Interior Valleys-
East Bay Hills and the Diablo Range-Santa Cruz Mountains-
Santa Clara Valley Including San Jose-Northern Monterey Bay-
Including the cities of San Francisco, Oakland, Fremont, Hayward,
Daly City, Berkeley, Pacifica, Concord, Antioch, Livermore, 
Walnut Creek, Pleasanton, Pittsburg, San Ramon, Blackhawk, 
Scotts Valley, Boulder Creek, Day Valley, San Jose, Santa Cruz, 
Watsonville, and Live Oak
755 AM PST Sun Dec 12 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 4 PM THIS AFTERNOON TO
7 AM PST MONDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 55 mph 
  expected.

* WHERE...Portions of northern California.

* WHEN...From 4 PM this afternoon to 7 AM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

CAZ517-528-530-130700-
/O.CON.KMTR.WI.Y.0014.211213T0900Z-211214T0000Z/
Santa Lucia Mountains and Los Padres National Forest-
Northern Salinas Valley/Hollister Valley and Carmel Valley-
Southern Monterey Bay and Big Sur Coast-
Including the cities of Salinas, Seaside, Monterey, and Marina
755 AM PST Sun Dec 12 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 1 AM TO 4 PM PST MONDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 60 mph 
  expected.

* WHERE...Santa Lucia Mountains and Los Padres National Forest, 
  Southern Monterey Bay and Big Sur Coast and Northern Salinas 
  Valley/Hollister Valley and Carmel Valley.

* WHEN...From 1 AM to 4 PM PST Monday.

* IMPACTS...Gusty winds could blow around unsecured objects. 
  Tree limbs could be blown down and a few power outages may 
  result.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Use extra caution when driving, especially if operating a high
profile vehicle. Secure outdoor objects.

&&

$$

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.

IssuedProductOfficeCountiesLasted
Dec 12, 8:41 AM PSTFlash Flood WatchMTRMonterey, San Benito, San Mateo, Santa Clara, Santa Cruz40 hr
Dec 12, 11:55 AM PSTHigh Wind WarningMTRMonterey, San Benito34 hr

Nearby

Freeze Warnings in California, 2021Every freeze 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.