Alert archive / California / Frost Advisories in 2019

Frost Advisory 21, NWS Eureka, CA

October 1, 2019Humboldt County, Mendocino County, Trinity County, California

NWS Eureka, CA issued this frost advisory at Oct 1, 2019, 8:30 PM PDT for Humboldt County, Mendocino County, Trinity County, California. It took effect at Oct 2, 2019, 3:00 AM PDT. It was in force for 6 hr.

The area

The counties it named.

The facts

Issued
Oct 1, 2019, 8:30 PM PDT (03:30 UTC)
In effect from
Oct 2, 2019, 3:00 AM PDT
Expired
Oct 2, 2019, 9:00 AM PDT
In force
6 hr
Issued by
NWS Eureka, CA

Counties Humboldt County, CA, Mendocino County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 73 km from the middle of the area, began a volume at 03:35 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 00:00Z, 3.5 hours before the alert went out and 241 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 00:00Z on 2019-10-02Temperature 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 00:00Z on 2019-10-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -18 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
1980 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
-18 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

270 
WWUS76 KEKA 020330
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
830 PM PDT Tue Oct 1 2019

CAZ106>108-110-111-021600-
/O.NEW.KEKA.FR.Y.0021.191002T1000Z-191002T1600Z/
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
830 PM PDT Tue Oct 1 2019

...FROST ADVISORY IN EFFECT FROM 3 AM TO 9 AM PDT WEDNESDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 3 AM to 9 AM PDT Wednesday. 

* LOW TEMPERATURES...mid 30s.

* LOCATIONS INCLUDE...Bridgeville, Dinsmore, Weaverville, Trinity
  Center, Hayfork, Douglas City, Ruth, Brooktrails, Willits, Dos
  Rios, Covelo and Potter Valley.

* 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 expected. Sensitive outdoor 
plants may be killed if left uncovered.

&&

$$
2 follow-up statements
632 
WWUS76 KEKA 021051
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
351 AM PDT Wed Oct 2 2019

CAZ106>108-110-111-021600-
/O.CON.KEKA.FR.Y.0021.000000T0000Z-191002T1600Z/
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
351 AM PDT Wed Oct 2 2019

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

* LOW TEMPERATURES...mid 30s.

* LOCATIONS INCLUDE...Bridgeville, Dinsmore, Weaverville, Trinity
  Center, Hayfork, Douglas City, Ruth, Brooktrails, Willits, Dos
  Rios, Covelo and Potter Valley.

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

$$
630 
WWUS76 KEKA 021553
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
853 AM PDT Wed Oct 2 2019



CAZ106>108-110-111-021700-
/O.EXP.KEKA.FR.Y.0021.000000T0000Z-191002T1600Z/
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
853 AM PDT Wed Oct 2 2019

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


$$

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 2, 8:07 AM PDTSmall Craft AdvisoryEKA40 hr
Oct 2, 2:08 PM PDTFrost AdvisoryEKAMendocino, Trinity13 hr

Nearby

Frost Advisories in California, 2019Every frost advisory in 2019

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.