Alert archive / California / Freeze Warnings in 2021

Freeze Warning 25, NWS Eureka, CA

December 10, 2021Humboldt County, Lake County, Mendocino County, California

NWS Eureka, CA issued this freeze warning at Dec 10, 2021, 2:59 PM PST for Humboldt County, Lake County, Mendocino County, California. It took effect at Dec 10, 2021, 11:00 PM PST. It was in force for 10 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 10, 2021, 2:59 PM PST (22:59 UTC)
In effect from
Dec 10, 2021, 11:00 PM PST
Expired
Dec 11, 2021, 9:00 AM PST
In force
10 hr
Issued by
NWS Eureka, CA

Counties Humboldt County, CA, Lake County, CA, Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 115 km from the middle of the area, began a volume at 23:03 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, 11.0 hours before the alert went out and 246 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 12:00Z on 2021-12-10Temperature 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 12:00Z on 2021-12-10The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -66 square meters per square second.1939587897Sfc1 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
1499 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
-66 m²/s²
0-3 km storm-relative helicity
20 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

700 
WWUS76 KEKA 102259
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
259 PM PST Fri Dec 10 2021

CAZ104-106-110700-
/O.NEW.KEKA.FZ.W.0025.211211T0700Z-211211T1700Z/
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Southwestern Humboldt-Southern Humboldt Interior-
259 PM PST Fri Dec 10 2021

...FREEZE WARNING IN EFFECT FROM 11 PM THIS EVENING TO 9 AM PST
SATURDAY...
...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY ABOVE 1500 FEET...

* WHAT...For the Freeze Warning, sub-freezing temperatures as 
  low as 30 expected. For the Wind Advisory above 1500 feet, 
  south winds 20 to 30 mph with gusts up to 50 mph expected.

* WHERE...Southwestern Humboldt and Southern Humboldt Interior 
  Counties.

* WHEN...For the Freeze Warning, from 11 PM this evening to 9 AM 
  PST Saturday. For the Wind Advisory, from 9 AM to 10 PM PST 
  Saturday.

* 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 and other 
  sensitive vegetation.

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. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ109-112>115-110700-
/O.NEW.KEKA.FZ.W.0025.211211T0700Z-211211T1700Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Northern Lake-Southern Lake-
259 PM PST Fri Dec 10 2021

...FREEZE WARNING IN EFFECT FROM 11 PM THIS EVENING TO 9 AM PST
SATURDAY...

* WHAT...Sub-freezing temperatures as low as 30 expected.

* WHERE...Mendocino Coast, Southwestern Mendocino Interior, 
  Southeastern Mendocino Interior, Northern Lake and Southern 
  Lake Counties.

* WHEN...From 11 PM this evening to 9 AM PST Saturday.

* IMPACTS...Frost and freeze conditions will kill crops and 
  other sensitive vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ101-110700-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Coastal Del Norte-
259 PM PST Fri Dec 10 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 50 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...From 9 AM to 10 PM PST Saturday.

* 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.

&&

$$

CAZ102-105-110700-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Del Norte Interior-Northern Humboldt Interior-
259 PM PST Fri Dec 10 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY ABOVE 1500 FEET...

* WHAT...South winds 25 to 35 mph with gusts up to 55 mph 
  expected above 1500 feet.

* WHERE...Del Norte Interior and Northern Humboldt Interior 
  Counties.

* WHEN...From 9 AM to 10 PM PST Saturday.

* 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.

&&

$$
3 follow-up statements
607 
WWUS76 KEKA 110419
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
819 PM PST Fri Dec 10 2021

CAZ114-110530-
/O.CAN.KEKA.FZ.W.0025.211211T0700Z-211211T1700Z/
Northern Lake-
819 PM PST Fri Dec 10 2021

...FREEZE WARNING IS CANCELLED...


$$

CAZ104-106-111230-
/O.CON.KEKA.FZ.W.0025.211211T0700Z-211211T1700Z/
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Southwestern Humboldt-Southern Humboldt Interior-
819 PM PST Fri Dec 10 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM PST SATURDAY...
...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY ABOVE 1500 FEET...

* WHAT...For the Freeze Warning, sub-freezing temperatures as 
  low as 29 expected. For the Wind Advisory above 1500 feet, 
  south winds 20 to 30 mph with gusts up to 50 mph expected.

* WHERE...Southwestern Humboldt and Southern Humboldt Interior 
  Counties.

* WHEN...For the Freeze Warning, until 9 AM PST Saturday. For 
  the Wind Advisory, from 9 AM to 10 PM PST Saturday.

* 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 and other 
  sensitive vegetation.

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. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ109-112-113-115-111230-
/O.CON.KEKA.FZ.W.0025.211211T0700Z-211211T1700Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
819 PM PST Fri Dec 10 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM PST SATURDAY...

* WHAT...Sub-freezing temperatures as low as 30 expected.

* WHERE...Mendocino Coast, Southeastern Mendocino Interior, 
  Southwestern Mendocino Interior and Southern Lake Counties.

* WHEN...Until 9 AM PST Saturday.

* IMPACTS...Frost and freeze conditions will kill crops and 
  other sensitive vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ101-111230-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Coastal Del Norte-
819 PM PST Fri Dec 10 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY...

* WHAT...South winds 20 to 30 mph with gusts up to 50 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...From 9 AM to 10 PM PST Saturday.

* 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.

&&

$$

CAZ102-105-111230-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Del Norte Interior-Northern Humboldt Interior-
819 PM PST Fri Dec 10 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM TO 10 PM PST
SATURDAY ABOVE 1500 FEET...

* WHAT...South winds 25 to 35 mph with gusts up to 50 mph 
  expected above 1500 feet.

* WHERE...Del Norte Interior and Northern Humboldt Interior 
  Counties.

* WHEN...From 9 AM to 10 PM PST Saturday.

* 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.

&&

$$
506 
WWUS76 KEKA 111147
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
347 AM PST Sat Dec 11 2021

CAZ104-106-112000-
/O.CON.KEKA.FZ.W.0025.000000T0000Z-211211T1700Z/
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Southwestern Humboldt-Southern Humboldt Interior-
347 AM PST Sat Dec 11 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM PST THIS MORNING...
...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM THIS MORNING TO
10 PM PST THIS EVENING ABOVE 1500 FEET...

* WHAT...For the Freeze Warning, sub-freezing temperatures in the
  upper 20s and low 30s. For the Wind Advisory above 1500 feet, 
  south winds 20 to 30 mph with gusts up to 50 mph expected.

* WHERE...Ridgetops and exposed areas above 1500 feet elevation in
  Southwestern Humboldt and Southern Humboldt Interior Counties.

* WHEN...For the Freeze Warning, until 9 AM PST this morning. 
  For the Wind Advisory, from 9 AM this morning to 10 PM PST 
  this evening.

* 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 and other 
  sensitive vegetation.

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. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ109-112-113-115-111700-
/O.CON.KEKA.FZ.W.0025.000000T0000Z-211211T1700Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
347 AM PST Sat Dec 11 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 9 AM PST THIS MORNING...

* WHAT...Sub-freezing temperatures in the upper 20s and low 30s.

* WHERE...Mendocino Coast, Southeastern Mendocino Interior, 
  Southwestern Mendocino Interior and Southern Lake Counties.

* WHEN...Until 9 AM PST this morning.

* IMPACTS...Frost and freeze conditions will kill crops and 
  other sensitive vegetation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold. Provide
adequate shelter for outdoor pets or consider bringing them
indoors.

Frost Advisories and Freeze Warnings are issued during the local
growing season as defined by climatology and local agriculture
experts. Once the growing season has ended these statements will
no longer be issued until the spring.

&&

$$

CAZ101-112000-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Coastal Del Norte-
347 AM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM THIS MORNING TO
10 PM PST THIS EVENING...

* WHAT...South winds 20 to 30 mph with gusts up to 50 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...From 9 AM this morning to 10 PM PST this evening.

* 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.

&&

$$

CAZ102-105-112000-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Del Norte Interior-Northern Humboldt Interior-
347 AM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 9 AM THIS MORNING TO
10 PM PST THIS EVENING ABOVE 1500 FEET...

* WHAT...South winds 25 to 35 mph with gusts up to 55 mph 
  expected above 1500 feet.

* WHERE...Ridgetops and exposed areas above 1500 feet elevation 
  in the Del Norte Interior and Northern Humboldt Interior 
  Counties.

* WHEN...From 9 AM this morning to 10 PM PST this evening.

* 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.

&&

$$
625 
WWUS76 KEKA 111648
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
848 AM PST Sat Dec 11 2021

CAZ104-106-120100-
/O.EXP.KEKA.FZ.W.0025.000000T0000Z-211211T1700Z/
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Southwestern Humboldt-Southern Humboldt Interior-
848 AM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING
ABOVE 1500 FEET...
...FREEZE WARNING WILL EXPIRE AT 9 AM PST THIS MORNING...

* WHAT...South winds 20 to 30 mph with gusts up to 50 mph 
  expected above 1500 feet.

* WHERE...Southwestern Humboldt and Southern Humboldt Interior 
  Counties.

* WHEN...Until 10 PM PST this evening.

* 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.

&&

$$

CAZ109-112-113-115-111800-
/O.EXP.KEKA.FZ.W.0025.000000T0000Z-211211T1700Z/
Mendocino Coast-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake-
848 AM PST Sat Dec 11 2021

...FREEZE WARNING WILL EXPIRE AT 9 AM PST THIS MORNING...

$$

CAZ101-120100-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Coastal Del Norte-
848 AM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING...

* WHAT...South winds 20 to 30 mph with gusts up to 50 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...Until 10 PM PST this evening.

* 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.

&&

$$

CAZ102-105-120100-
/O.CON.KEKA.WI.Y.0019.211211T1700Z-211212T0600Z/
Del Norte Interior-Northern Humboldt Interior-
848 AM PST Sat Dec 11 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 10 PM PST THIS EVENING
ABOVE 1500 FEET...

* WHAT...South winds 25 to 35 mph with gusts up to 55 mph 
  expected above 1500 feet.

* WHERE...Del Norte Interior and Northern Humboldt Interior 
  Counties.

* WHEN...Until 10 PM PST this evening.

* 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.

&&

$$

The office that day

Everything else NWS Eureka, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 9, 5:31 PM PSTWind AdvisoryEKADel Norte, Humboldt52 hr
Dec 10, 3:03 AM PSTGale WarningEKA46 hr
Dec 10, 3:03 AM PSTSmall Craft AdvisoryEKA36 hr
Dec 10, 1:54 PM PSTWinter Storm WarningEKATrinity39 hr
Dec 10, 3:00 PM PSTGale WatchEKA4 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.