Alert archive / California / Frost Advisories in 2017

Frost Advisory 9, NWS Eureka, CA

April 14, 20174 counties in California

NWS Eureka, CA issued this frost advisory at Apr 14, 2017, 7:11 PM PDT for 4 counties in California. It took effect at Apr 15, 2017, 3:00 AM PDT. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Apr 14, 2017, 7:11 PM PDT (02:11 UTC)
In effect from
Apr 15, 2017, 3:00 AM PDT
Expired
Apr 15, 2017, 8:00 AM PDT
In force
5 hr
Issued by
NWS Eureka, CA

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

The radar

The Eureka (Bunker Hill) radar (KBHX), 60 km from the middle of the area, began a volume at 02:12 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, 2.2 hours before the alert went out and 204 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 2017-04-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 79 joules per kilogram.LCLLFCEL10008507005003002001001 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 2017-04-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
79 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1698 m above ground
0-6 km bulk shear
48 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
17 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

158 
WWUS76 KEKA 150211
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
711 PM PDT Fri Apr 14 2017

CAZ101>106-109>113-151500-
/O.NEW.KEKA.FR.Y.0009.170415T1000Z-170415T1500Z/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-Mendocino Coast-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
711 PM PDT Fri Apr 14 2017

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM PDT SATURDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 3 AM to 8 AM PDT Saturday. 

* LOCATIONS INCLUDE...Crescent City...Gasquet...Arcata...
  Eureka...Fortuna...Patrolia...Honeydew...Ettersberg... Willow
  Creek...Orleans...Garberville...Bridgeville... Fort Bragg...
  Point Arena...Leggett...Laytonville...Willits...Covelo...
  Boonville...Comptche...Ukiah...Hopland.

* LOW TEMPERATURES...33 to 36.

* 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
513 
WWUS76 KEKA 150517
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1017 PM PDT Fri Apr 14 2017


CAZ107-108-151500-
/O.EXA.KEKA.FR.Y.0009.170415T1000Z-170415T1500Z/
Northern Trinity-Southern Trinity-
1017 PM PDT Fri Apr 14 2017

...FROST ADVISORY IN EFFECT FROM 3 AM TO 8 AM PDT SATURDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 3 AM to 8 AM PDT Saturday. 

* LOCATIONS INCLUDE...Weaverville...Burnt Ranch...Trinity
  Center...Hayfork...Ruth.

* LOW TEMPERATURES...31 to 35.

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

$$

CAZ101>106-109>113-151500-
/O.CON.KEKA.FR.Y.0009.170415T1000Z-170415T1500Z/
Coastal Del Norte-Del Norte Interior-Northern Humboldt Coast-
Southwestern Humboldt-Northern Humboldt Interior-
Southern Humboldt Interior-Mendocino Coast-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
Southwestern Mendocino Interior-Southeastern Mendocino Interior-
1017 PM PDT Fri Apr 14 2017

...FROST ADVISORY REMAINS IN EFFECT FROM 3 AM TO 8 AM PDT
SATURDAY...

* LOCATIONS INCLUDE...Crescent City...Gasquet...Arcata...
  Eureka...Fortuna...Patrolia...Honeydew...Ettersberg... Willow
  Creek...Orleans...Garberville...Bridgeville... Fort Bragg...
  Point Arena...Leggett...Laytonville...Willits...Covelo...
  Boonville...Comptche...Ukiah...Hopland.

* LOW TEMPERATURES...33 to 36.

* 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
Apr 15, 2:02 PM PDTSmall Craft AdvisoryEKA56 hr

Nearby

Frost Advisories in California, 2017Every frost advisory in 2017

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.