Alert archive / California / Frost Advisories in 2018

Frost Advisory 38, NWS Eureka, CA

December 5, 2018Del Norte County, Humboldt County, California

NWS Eureka, CA issued this frost advisory at Dec 5, 2018, 2:56 PM PST for Del Norte County, Humboldt County, California. It took effect at Dec 6, 2018, 12:00 AM PST. It was in force for 9 hr.

The area

The counties it named.

The facts

Issued
Dec 5, 2018, 2:56 PM PST (22:56 UTC)
In effect from
Dec 6, 2018, 12:00 AM PST
Expired
Dec 6, 2018, 9:00 AM PST
In force
9 hr
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 86 km from the middle of the area, began a volume at 22:56 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

Medford/Jackson, OR (KMFR), launched 12:00Z, 10.9 hours before the alert went out and 158 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, Medford/Jackson, OR at 12:00Z on 2018-12-05Temperature 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, Medford/Jackson, OR at 12:00Z on 2018-12-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
1220 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
33 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

677 
WWUS76 KEKA 052256
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
256 PM PST Wed Dec 5 2018

CAZ101>103-061200-
/O.NEW.KEKA.FR.Y.0038.181206T0800Z-181206T1700Z/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
256 PM PST Wed Dec 5 2018

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 9 AM PST
THURSDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from midnight tonight to 9 AM PST
Thursday. 

* LOW TEMPERATURES...mid 30s.

* LOCATIONS INCLUDE...Areas away from the immediate coast in
  Crescent City, Gasquet, Arcata, Eureka, and Fortuna.

* FOR A DETAILED VIEW OF THE HAZARD AREA...visit 
  http://www.wrh.noaa.gov/map

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that frost is possible. Sensitive outdoor
plants may be killed if left uncovered.

&&

$$
2 follow-up statements
502 
WWUS76 KEKA 061145
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
345 AM PST Thu Dec 6 2018

CAZ101>103-061700-
/O.CON.KEKA.FR.Y.0038.000000T0000Z-181206T1700Z/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
345 AM PST Thu Dec 6 2018

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

* LOW TEMPERATURES...mid 30s.

* LOCATIONS INCLUDE...Areas away from the immediate coast in
  Crescent City, Gasquet, Arcata, Eureka, and Fortuna.

* FOR A DETAILED VIEW OF THE HAZARD AREA...visit 
  http://www.wrh.noaa.gov/map

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Frost Advisory means that frost is possible. Sensitive outdoor
plants may be killed if left uncovered.

$$
721 
WWUS76 KEKA 061645
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
845 AM PST Thu Dec 6 2018

CAZ101>103-061745-
/O.EXP.KEKA.FR.Y.0038.000000T0000Z-181206T1700Z/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
845 AM PST Thu Dec 6 2018

...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
Dec 5, 3:18 AM PSTSmall Craft AdvisoryEKA6 hr
Dec 5, 3:18 AM PSTSmall Craft AdvisoryEKA48 hr

Nearby

Frost Advisories in California, 2018Every frost advisory in 2018

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.