Alert archive / California / Frost Advisories in 2020

Frost Advisory 3, NWS Eureka, CA

March 3, 2020Mendocino County, California

NWS Eureka, CA issued this frost advisory at Mar 3, 2020, 4:45 AM PST for Mendocino County, California. It was in force for 4 hr.

The area

The counties it named.

The facts

Issued
Mar 3, 2020, 4:45 AM PST (12:45 UTC)
Expired
Mar 3, 2020, 9:00 AM PST
In force
4 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 12:44 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, 0.8 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 2020-03-03Temperature 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 2020-03-03The 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
2351 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
-23 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

696 
WWUS76 KEKA 031245
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
445 AM PST Tue Mar 3 2020

CAZ110>113-031700-
/O.NEW.KEKA.FR.Y.0003.200303T1245Z-200303T1700Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
445 AM PST Tue Mar 3 2020

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

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

* WHERE...Low lying wind-protected valleys of interior Mendocino
  County. Includes Willits, Boonville, Potter Valley, Covelo, 
  Leggett, Laytonville, Ukiah, Hopland. 

* WHEN...Until 9 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.

&&

$$
1 follow-up statement
853 
WWUS76 KEKA 031700
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
900 AM PST Tue Mar 3 2020

CAZ110>113-031800-
/O.EXP.KEKA.FR.Y.0003.000000T0000Z-200303T1700Z/
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
900 AM PST Tue Mar 3 2020

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


$$

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 3, 1:33 PM PSTFrost AdvisoryEKALake, Mendocino19 hr
Mar 3, 3:12 PM PSTHazardous Seas WarningEKA15 hr

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.