Alert archive / California / Freeze Warnings in 2021

Freeze Warning 26, NWS Eureka, CA

December 29, 2021Del Norte County, Humboldt County, Mendocino County, California

NWS Eureka, CA issued this freeze warning at Dec 29, 2021, 3:24 AM PST for Del Norte County, Humboldt County, Mendocino County, California. It took effect at Dec 30, 2021, 12:00 AM PST. It was in force for 9 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 29, 2021, 3:24 AM PST (11:24 UTC)
In effect from
Dec 30, 2021, 12:00 AM PST
Expired
Dec 30, 2021, 9:00 AM PST
In force
9 hr
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA, Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 47 km from the middle of the area, began a volume at 11:26 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

Medford/Jackson, OR (KMFR), launched 00:00Z, 11.4 hours before the alert went out and 210 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, Medford/Jackson, OR at 00:00Z on 2021-12-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCLEL10008507005003002001001 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, Medford/Jackson, OR at 00:00Z on 2021-12-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 86 square meters per square second.193958Sfc1 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
534 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
86 m²/s²
0-3 km storm-relative helicity
261 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

048 
WWUS76 KEKA 291124
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
324 AM PST Wed Dec 29 2021

CAZ101-103-109-291930-
/O.UPG.KEKA.FZ.A.0014.211230T0800Z-211230T1700Z/
/O.NEW.KEKA.FZ.W.0026.211230T0800Z-211230T1700Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
324 AM PST Wed Dec 29 2021

...FREEZE WARNING IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM PST
THURSDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...Coastal Del Norte, Northern Humboldt Coast and 
  Mendocino Coast Counties.

* WHEN...From midnight tonight to 9 AM PST Thursday.

* 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.

&&

$$
4 follow-up statements
885 
WWUS76 KEKA 291755
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
955 AM PST Wed Dec 29 2021

CAZ101-103-109-300200-
/O.CON.KEKA.FZ.W.0026.211230T0800Z-211230T1700Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
955 AM PST Wed Dec 29 2021

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
PST THURSDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...Coastal Del Norte, Mendocino Coast and Northern 
  Humboldt Coast Counties.

* WHEN...From midnight tonight to 9 AM PST Thursday.

* 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.

&&

$$
693 
WWUS76 KEKA 292308
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
308 PM PST Wed Dec 29 2021

CAZ101-103-109-300715-
/O.CON.KEKA.FZ.W.0026.211230T0800Z-211230T1700Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
308 PM PST Wed Dec 29 2021

...FREEZE WARNING REMAINS IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM
PST THURSDAY...

* WHAT...Sub-freezing temperatures as low as 29 expected.

* WHERE...Coastal Del Norte, Mendocino Coast and Northern 
  Humboldt Coast Counties.

* WHEN...From midnight tonight to 9 AM PST Thursday.

* 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.

&&

$$
411 
WWUS76 KEKA 300658
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1058 PM PST Wed Dec 29 2021

CAZ101-103-109-301700-
/O.CON.KEKA.FZ.W.0026.211230T0800Z-211230T1700Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
1058 PM PST Wed Dec 29 2021

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

* WHAT...Sub-freezing temperatures as low as 28 expected.

* WHERE...Coastal Del Norte, Mendocino Coast and Northern 
  Humboldt Coast Counties.

* WHEN...Until 9 AM PST Thursday.

* 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.

&&

$$
786 
WWUS76 KEKA 301645
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
845 AM PST Thu Dec 30 2021

CAZ101-103-109-301745-
/O.EXP.KEKA.FZ.W.0026.000000T0000Z-211230T1700Z/
Coastal Del Norte-Northern Humboldt Coast-Mendocino Coast-
845 AM PST Thu Dec 30 2021

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


$$

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.