Alert archive / California / Frost Advisories in 2021

Frost Advisory 10, NWS Eureka, CA

March 13, 2021Mendocino County, California

NWS Eureka, CA issued this frost advisory at Mar 13, 2021, 12:36 PM PST for Mendocino County, California. It took effect at Mar 13, 2021, 11:00 PM PST. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Mar 13, 2021, 12:36 PM PST (20:36 UTC)
In effect from
Mar 13, 2021, 11:00 PM PST
Expired
Mar 14, 2021, 8:00 AM PDT
In force
8 hr
Issued by
NWS Eureka, CA

County Mendocino County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 139 km from the middle of the area, began a volume at 20:39 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, 8.6 hours before the alert went out and 218 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 2021-03-13Temperature 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 2021-03-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 102 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
852 m above ground
0-6 km bulk shear
45 kt
0-1 km storm-relative helicity
102 m²/s²
0-3 km storm-relative helicity
141 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

298 
WWUS76 KEKA 132036
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1236 PM PST Sat Mar 13 2021

CAZ111-114-140445-
/O.NEW.KEKA.FZ.W.0009.210314T0700Z-210314T1500Z/
Northeastern Mendocino Interior-Northern Lake County-
1236 PM PST Sat Mar 13 2021

...FREEZE WARNING IN EFFECT FROM 11 PM PST THIS EVENING TO 8 AM
PDT SUNDAY...

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

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

* WHEN...From 11 PM PST this evening to 8 AM PDT Sunday.

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

* ADDITIONAL DETAILS...Temperatures are expected to drop quickly
  this evening before leveling off later tonight as high clouds
  start to move into the area. 

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.

&&

$$

CAZ110-112-113-115-140445-
/O.NEW.KEKA.FR.Y.0010.210314T0700Z-210314T1500Z/
Northwestern Mendocino Interior-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake County-
1236 PM PST Sat Mar 13 2021

...FROST ADVISORY IN EFFECT FROM 11 PM PST THIS EVENING TO 8 AM
PDT SUNDAY...

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

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

* WHEN...From 11 PM PST this evening to 8 AM PDT Sunday.

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

* ADDITIONAL DETAILS...Temperatures are expected to drop quickly
  this evening before leveling off later tonight as high clouds
  start to move into the area. 

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.

&&

$$
2 follow-up statements
093 
WWUS76 KEKA 140214
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
614 PM PST Sat Mar 13 2021

CAZ111-114-141015-
/O.CON.KEKA.FZ.W.0009.210314T0700Z-210314T1500Z/
Northeastern Mendocino Interior-Northern Lake County-
614 PM PST Sat Mar 13 2021

...FREEZE WARNING REMAINS IN EFFECT FROM 11 PM PST THIS EVENING
TO 8 AM PDT SUNDAY...

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

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

* WHEN...From 11 PM PST this evening to 8 AM PDT Sunday.

* 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.

&&

$$

CAZ110-112-113-115-141015-
/O.CON.KEKA.FR.Y.0010.210314T0700Z-210314T1500Z/
Northwestern Mendocino Interior-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake County-
614 PM PST Sat Mar 13 2021

...FROST ADVISORY REMAINS IN EFFECT FROM 11 PM PST THIS EVENING
TO 8 AM PDT SUNDAY...

* WHAT...Temperatures as low as 33 will result in frost 
  formation.

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

* WHEN...From 11 PM PST this evening to 8 AM PDT Sunday.

* 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.

&&

$$
030 
WWUS76 KEKA 141004
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
304 AM PDT Sun Mar 14 2021

CAZ111-114-141500-
/O.CON.KEKA.FZ.W.0009.000000T0000Z-210314T1500Z/
Northeastern Mendocino Interior-Northern Lake County-
304 AM PDT Sun Mar 14 2021

...FREEZE WARNING REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

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

* WHERE...Northeastern Mendocino Interior and Northern Lake County.

* WHEN...Until 8 AM PDT 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.

&&

$$

CAZ110-112-113-115-141500-
/O.CON.KEKA.FR.Y.0010.000000T0000Z-210314T1500Z/
Northwestern Mendocino Interior-Southwestern Mendocino Interior-
Southeastern Mendocino Interior-Southern Lake County-
304 AM PDT Sun Mar 14 2021

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

* WHAT...Temperatures as low as 35 will result in frost 
  formation.

* WHERE...Southwestern Mendocino Interior, Southeastern Mendocino
  Interior, Northwestern Mendocino Interior and Southern Lake
  County.

* WHEN...Until 8 AM PDT 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.

&&

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 12, 5:07 PM PSTGale WatchEKA9 hr
Mar 13, 2:35 AM PSTGale WarningEKA35 hr
Mar 13, 2:35 AM PSTSmall Craft AdvisoryEKA43 hr
Mar 13, 4:13 AM PSTWinter Weather AdvisoryEKADel Norte, Humboldt, Lake, Mendocino, Trinity50 hr
Mar 13, 12:36 PM PSTFreeze WarningEKALake, Mendocino18 hr

Nearby

Frost Advisories in California, 2021Every frost advisory 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.