Alert archive / California / Freeze Watches in 2021

Freeze Watch 9, NWS Eureka, CA

November 5, 2021Humboldt County, Lake County, Mendocino County, California

NWS Eureka, CA issued this freeze watch at Nov 5, 2021, 2:54 AM PDT for Humboldt County, Lake County, Mendocino County, California. It took effect at Nov 7, 2021, 2:00 AM PST. It was in force for .

The area

The counties it named.

The facts

Issued
Nov 5, 2021, 2:54 AM PDT (09:54 UTC)
In effect from
Nov 7, 2021, 2:00 AM PST
Expired
Nov 6, 2021, 3:28 AM PDT
In force
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 09:54 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.

The nearest sounding before it

Oakland, CA (KOAK), launched 00:00Z, 9.9 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 00:00Z on 2021-11-05Temperature 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 2021-11-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -70 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
1031 m above ground
0-6 km bulk shear
41 kt
0-1 km storm-relative helicity
-70 m²/s²
0-3 km storm-relative helicity
-8 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

090 
WWUS76 KEKA 050954
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
254 AM PDT Fri Nov 5 2021

CAZ110-111-114-051800-
/O.NEW.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
254 AM PDT Fri Nov 5 2021

...FREEZE WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH SUNDAY
MORNING BELOW 3000 FEET...

* WHAT...Sub-freezing temperatures possible below 3000 feet.

* WHERE...Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior and Northern Lake Counties.

* WHEN...From late Saturday night through Sunday morning.

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

* ADDITIONAL DETAILS...Low overnight temperatures are possible
  early Monday morning for clear valleys. 

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.

&&

$$
5 follow-up statements
266 
WWUS76 KEKA 050956
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
256 AM PDT Fri Nov 5 2021

CAZ110-111-114-052200-
/O.CON.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
256 AM PDT Fri Nov 5 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING BELOW 3000 FEET...

* WHAT...Sub-freezing temperatures None possible below 3000 feet.

* WHERE...Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior and Northern Lake Counties.

* WHEN...From late Saturday night through Sunday morning.

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

* ADDITIONAL DETAILS...Low overnight temperatures are possible
  early Sunday morning for clear valleys.

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.

&&

$$
403 
WWUS76 KEKA 051948
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1248 PM PDT Fri Nov 5 2021

CAZ110-111-114-060400-
/O.CON.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
1248 PM PDT Fri Nov 5 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING BELOW 3000 FEET...

* WHAT...Sub-freezing temperatures None possible below 3000 feet.

* WHERE...Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior and Northern Lake Counties.

* WHEN...From late Saturday night through Sunday morning.

* IMPACTS...Frost and freeze conditions could 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.

&&

$$
756 
WWUS76 KEKA 052217
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
317 PM PDT Fri Nov 5 2021

CAZ106-060630-
/O.EXA.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Southern Humboldt Interior-
317 PM PDT Fri Nov 5 2021

...FREEZE WATCH IN EFFECT FROM LATE SATURDAY NIGHT THROUGH SUNDAY
MORNING...

* WHAT...Sub-freezing temperatures as low as 31 possible.

* WHERE...Southern Humboldt Interior County.

* WHEN...From late Saturday night through Sunday morning.

* IMPACTS...Frost and freeze conditions could 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.

&&

$$

CAZ110-111-114-060630-
/O.CON.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake-
317 PM PDT Fri Nov 5 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING...

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

* WHERE...Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior and Northern Lake Counties.

* WHEN...From late Saturday night through Sunday morning.

* IMPACTS...Frost and freeze conditions could 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.

&&

$$
549 
WWUS76 KEKA 060428
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
928 PM PDT Fri Nov 5 2021

CAZ106-110-111-114-061230-
/O.CON.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
Southern Humboldt Interior-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
928 PM PDT Fri Nov 5 2021

...FREEZE WATCH REMAINS IN EFFECT FROM LATE SATURDAY NIGHT
THROUGH SUNDAY MORNING...

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

* WHERE...Northwestern Mendocino Interior, Northeastern 
  Mendocino Interior, Northern Lake and Southern Humboldt 
  Interior Counties.

* WHEN...From late Saturday night through Sunday morning.

* IMPACTS...Frost and freeze conditions could 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.

&&

$$
922 
WWUS76 KEKA 061028
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
328 AM PDT Sat Nov 6 2021

CAZ106-110-111-114-061830-
/O.UPG.KEKA.FZ.A.0009.211107T1000Z-211107T1600Z/
/O.NEW.KEKA.FR.Y.0048.211107T1000Z-211107T1600Z/
/O.NEW.KEKA.FZ.A.0010.211108T1000Z-211108T1600Z/
Southern Humboldt Interior-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-Northern Lake-
328 AM PDT Sat Nov 6 2021

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM PST SUNDAY BELOW
3000 FEET...
...FREEZE WATCH IN EFFECT FROM LATE SUNDAY NIGHT THROUGH MONDAY
MORNING BELOW 3000 FEET...

* WHAT...For the Frost Advisory below 3000 feet, temperatures 
  None will result in frost formation. For the Freeze Watch 
  below 3000 feet, sub-freezing temperatures None possible.

* WHERE...Southern Humboldt Interior, Northwestern Mendocino 
  Interior, Northeastern Mendocino Interior and Northern Lake 
  Counties.

* WHEN...For the Frost Advisory, from 2 AM to 8 AM PST Sunday. 
  For the Freeze Watch, from late Sunday night through Monday 
  morning.

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

* ADDITIONAL DETAILS...Valley fog could help protect some areas
  from freezing temperatures, particularly on Sunday. 

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.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Nov 4, 8:36 PM PDTSmall Craft AdvisoryEKA12 hr
Nov 5, 9:02 AM PDTSmall Craft AdvisoryEKA41 hr
Nov 5, 2:30 PM PDTCoastal Flood AdvisoryEKAHumboldt24 hr

Nearby

Freeze Watches in California, 2021Every freeze watch 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.