Alert archive / California / Frost Advisories in 2020

Frost Advisory 13, NWS Eureka, CA

March 22, 2020Lake County, Mendocino County, California

NWS Eureka, CA issued this frost advisory at Mar 22, 2020, 2:21 PM PDT for Lake County, Mendocino County, California. It took effect at Mar 23, 2020, 1:00 AM PDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Mar 22, 2020, 2:21 PM PDT (21:21 UTC)
In effect from
Mar 23, 2020, 1:00 AM PDT
Expired
Mar 23, 2020, 9:00 AM PDT
In force
8 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 21:23 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, 9.4 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 12:00Z on 2020-03-22Temperature 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 2020-03-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
1066 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
41 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

172 
WWUS76 KEKA 222121
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
221 PM PDT Sun Mar 22 2020

CAZ110-111-114-230530-
/O.NEW.KEKA.FR.Y.0013.200323T0800Z-200323T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
221 PM PDT Sun Mar 22 2020

...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM PDT MONDAY...

* WHAT...Temperatures in the mid 30s will result in frost 
  formation.

* WHERE...Northern Mendocino interior and Northern Lake County 
  including Laytonville, Willits, Covelo, and Potter Valley

* WHEN...From 1 AM to 9 AM PDT Monday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
3 follow-up statements
082 
WWUS76 KEKA 230529
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1029 PM PDT Sun Mar 22 2020

CAZ110-111-114-231330-
/O.CON.KEKA.FR.Y.0013.200323T0800Z-200323T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
1029 PM PDT Sun Mar 22 2020

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM PDT MONDAY...

* WHAT...Temperatures in the mid 30s will result in frost 
  formation.

* WHERE...Northern Mendocino interior and Northern Lake County 
  including Laytonville, Willits, Covelo, and Potter Valley.

* WHEN...From 1 AM to 9 AM PDT Monday.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Take steps now to protect tender plants from the cold.

&&

$$
531 
WWUS76 KEKA 231327
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
627 AM PDT Mon Mar 23 2020

CAZ110-111-114-231600-
/O.CON.KEKA.FR.Y.0013.000000T0000Z-200323T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
627 AM PDT Mon Mar 23 2020

...FROST ADVISORY REMAINS IN EFFECT UNTIL 9 AM THIS MORNING...

* WHAT...Temperatures in the mid 30s will result in frost 
  formation.

* WHERE...Northern Mendocino interior and Northern Lake County 
  including Laytonville, Willits, Covelo, and Potter Valley.

* WHEN...Until 9 AM 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.

$$
775 
WWUS76 KEKA 231546
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
846 AM PDT Mon Mar 23 2020

CAZ110-111-114-231700-
/O.EXP.KEKA.FR.Y.0013.000000T0000Z-200323T1600Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Northern Lake County-
846 AM PDT Mon Mar 23 2020

...FROST ADVISORY WILL EXPIRE AT 9 AM PDT THIS MORNING...

$$

Nearby

Frost Advisories in California, 2020Every frost advisory in 2020

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.