Alert archive / California / Freeze Warnings in 2021

Freeze Warning 3, NWS Eureka, CA

March 4, 2021Lake County, Mendocino County, California

NWS Eureka, CA issued this freeze warning at Mar 4, 2021, 1:07 AM PST for Lake County, Mendocino County, California. It was in force for 7 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
Mar 4, 2021, 1:07 AM PST (09:07 UTC)
Expired
Mar 4, 2021, 8:00 AM PST
In force
7 hr
Issued by
NWS Eureka, CA

Counties Lake County, CA, Mendocino County, CA

The radar

The Beale AFB radar (KBBX), 128 km from the middle of the area, began a volume at 09:11 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, 9.1 hours before the alert went out and 188 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 2021-03-04Temperature 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 2021-03-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 square meters per square second.1939Sfc1 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
1319 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
-24 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

496 
WWUS76 KEKA 040907
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
107 AM PST Thu Mar 4 2021

CAZ110-111-114-041600-
/O.NEW.KEKA.FZ.W.0003.210304T0907Z-210304T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
107 AM PST Thu Mar 4 2021

...FREEZE WARNING IN EFFECT UNTIL 8 AM PST THIS MORNING...

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

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

* WHEN...Until 8 AM PST this morning.

* IMPACTS...Frost and freeze conditions will kill crops, other 
  sensitive vegetation and possibly damage unprotected outdoor 
  plumbing.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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..

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.

&&

$$

CAZ112-115-041600-
/O.NEW.KEKA.FR.Y.0004.210304T0907Z-210304T1600Z/
Southwestern Mendocino Interior-Southern Lake County-
107 AM PST Thu Mar 4 2021

...FROST ADVISORY IN EFFECT UNTIL 8 AM PST THIS MORNING...

* WHAT...Temperatures as low as 34 will result in frost 
  formation.

* WHERE...Southwestern Mendocino Interior and Southern Lake 
  County Counties.

* WHEN...Until 8 AM PST this morning.

* IMPACTS...Frost could kill sensitive outdoor vegetation if 
  left uncovered.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

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.

&&

$$

CAZ101-041715-
/O.CON.KEKA.WI.Y.0009.210304T1800Z-210305T1500Z/
Coastal Del Norte-
107 AM PST Thu Mar 4 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 10 AM THIS MORNING TO
7 AM PST FRIDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 45 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...From 10 AM Thursday to 7 AM PST Friday.

* 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.

&&

$$

CAZ102-104>106-041715-
/O.CON.KEKA.WI.Y.0009.210304T2300Z-210305T1500Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
107 AM PST Thu Mar 4 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO
7 AM PST FRIDAY ABOVE 1500 FEET...

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

* WHERE...Del Norte Interior, Northern Humboldt Interior, 
  Southwestern Humboldt and Southern Humboldt Interior Counties.

* WHEN...From 3 PM Thursday to 7 AM PST Friday.

* 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.

&&

$$
1 follow-up statement
795 
WWUS76 KEKA 041546
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
746 AM PST Thu Mar 4 2021

CAZ110-111-114-041700-
/O.EXP.KEKA.FZ.W.0003.000000T0000Z-210304T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
746 AM PST Thu Mar 4 2021

...FREEZE WARNING WILL EXPIRE AT 8 AM PST THIS MORNING...



$$

CAZ112-115-041700-
/O.EXP.KEKA.FR.Y.0004.000000T0000Z-210304T1600Z/
Southwestern Mendocino Interior-Southern Lake County-
746 AM PST Thu Mar 4 2021

...FROST ADVISORY WILL EXPIRE AT 8 AM PST THIS MORNING...



$$

CAZ101-050000-
/O.CON.KEKA.WI.Y.0009.210304T1800Z-210305T1500Z/
Coastal Del Norte-
746 AM PST Thu Mar 4 2021

...WIND ADVISORY REMAINS IN EFFECT UNTIL 7 AM PST FRIDAY...

* WHAT...South winds 15 to 25 mph with gusts up to 45 mph 
  expected.

* WHERE...Coastal Del Norte County.

* WHEN...Until 7 AM PST Friday.

* 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.

&&

$$

CAZ102-104>106-050000-
/O.CON.KEKA.WI.Y.0009.210304T2300Z-210305T1500Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-Southern Humboldt Interior-
746 AM PST Thu Mar 4 2021

...WIND ADVISORY REMAINS IN EFFECT FROM 3 PM THIS AFTERNOON TO
7 AM PST FRIDAY ABOVE 1500 FEET...

* WHAT...South winds 15 to 25 mph with gusts up to 50 mph 
  expected above 1500 feet.

* WHERE...Del Norte Interior, Northern Humboldt Interior, 
  Southwestern Humboldt and Southern Humboldt Interior Counties.

* WHEN...From 3 PM this afternoon to 7 AM PST Friday.

* 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
Mar 4, 1:07 AM PSTFrost AdvisoryEKAMendocino7 hr
Mar 4, 2:12 PM PSTWinter Weather AdvisoryEKADel Norte, Humboldt, Lake, Mendocino, Trinity36 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.