Alert archive / California / Frost Advisories in 2019

Frost Advisory 13, NWS Eureka, CA

May 1, 2019Del Norte County, Humboldt County, Trinity County, California

NWS Eureka, CA issued this frost advisory at May 1, 2019, 8:45 PM PDT for Del Norte County, Humboldt County, Trinity County, California. It took effect at May 2, 2019, 2:00 AM PDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
May 1, 2019, 8:45 PM PDT (03:45 UTC)
In effect from
May 2, 2019, 2:00 AM PDT
Expired
May 2, 2019, 9:00 AM PDT
In force
7 hr
Issued by
NWS Eureka, CA

Counties Del Norte County, CA, Humboldt County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 80 km from the middle of the area, began a volume at 03:46 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, 3.8 hours before the alert went out and 165 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 2019-05-02Temperature 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 2019-05-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 square meters per square second.1939587897Sfc1 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
3425 m above ground
0-6 km bulk shear
33 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
75 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

750 
WWUS76 KEKA 020345
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
845 PM PDT Wed May 1 2019

CAZ106>108-021500-
/O.NEW.KEKA.FR.Y.0013.190502T0900Z-190502T1500Z/
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
845 PM PDT Wed May 1 2019

...FROST ADVISORY IN EFFECT FROM 2 AM TO 8 AM PDT THURSDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 2 AM to 8 AM PDT Thursday. 

* LOW TEMPERATURES...mid 30s.

* LOCATIONS INCLUDE...Hayfork, Ruth, Dinsmore, and Douglas City.

* 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.

&&

$$
1 follow-up statement
582 
WWUS76 KEKA 021231
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
531 AM PDT Thu May 2 2019

CAZ102-104-105-021600-
/O.EXB.KEKA.FR.Y.0013.000000T0000Z-190502T1600Z/
Del Norte Interior-Southwestern Humboldt-
Northern Humboldt Interior-
531 AM PDT Thu May 2 2019

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

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect until 9 AM PDT this morning. 

* LOW TEMPERATURES...low to mid 30s.

* LOCATIONS INCLUDE...Gasquet, Petrolia, Honeydew, Orleans, 
  Willow Creek, Humboldt Redwoods.

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

$$

CAZ106>108-021600-
/O.EXT.KEKA.FR.Y.0013.000000T0000Z-190502T1600Z/
Southern Humboldt Interior-Northern Trinity-Southern Trinity-
531 AM PDT Thu May 2 2019

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

* LOW TEMPERATURES...Low to mid 30s.

* LOCATIONS INCLUDE...Hayfork, Ruth, Weaverville, Trinity Center,
  Garberville, Larabee Valley.

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

$$

The office that day

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

IssuedProductOfficeCountiesLasted
May 2, 1:57 PM PDTFrost AdvisoryEKADel Norte, Humboldt, Trinity18 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.