Alert archive / California / Frost Advisories in 2017

Frost Advisory 16, NWS Eureka, CA

September 22, 2017Mendocino County, Trinity County, California

NWS Eureka, CA issued this frost advisory at Sep 22, 2017, 3:08 PM PDT for Mendocino County, Trinity County, California. It took effect at Sep 23, 2017, 1:00 AM PDT. It was in force for 7 hr.

The area

The counties it named.

The facts

Issued
Sep 22, 2017, 3:08 PM PDT (22:08 UTC)
In effect from
Sep 23, 2017, 1:00 AM PDT
Expired
Sep 23, 2017, 8:00 AM PDT
In force
7 hr
Issued by
NWS Eureka, CA

Counties Mendocino County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 100 km from the middle of the area, began a volume at 22:10 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, 10.1 hours before the alert went out and 262 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 2017-09-22Temperature 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 2017-09-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
731 m above ground
0-6 km bulk shear
54 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
34 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

740 
WWUS76 KEKA 222208
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
308 PM PDT Fri Sep 22 2017

CAZ107-108-110-111-231115-
/O.NEW.KEKA.FR.Y.0016.170923T0800Z-170923T1500Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-
308 PM PDT Fri Sep 22 2017

...FROST ADVISORY IN EFFECT FROM 1 AM TO 8 AM PDT SATURDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 1 AM to 8 AM PDT Saturday. 

* TEMPERATURES...33 to 36 degrees.

* LOCATIONS INCLUDE...Weaverville...Trinity
  Center...Hayfork...Ruth...Leggett...Laytonville...Willits...
  Covelo.

* 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
420 
WWUS76 KEKA 230901
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
201 AM PDT Sat Sep 23 2017

CAZ107-108-110-111-231500-
/O.CON.KEKA.FR.Y.0016.000000T0000Z-170923T1500Z/
Northern Trinity-Southern Trinity-Northwestern Mendocino Interior-
Northeastern Mendocino Interior-
201 AM PDT Sat Sep 23 2017

...FROST ADVISORY REMAINS IN EFFECT UNTIL 8 AM PDT THIS MORNING...

* TEMPERATURES...33 to 36 degrees.

* LOCATIONS INCLUDE...Weaverville...Trinity
  Center...Hayfork...Ruth...Leggett...Laytonville...Willits...
  Covelo.

* 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.


$$

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 22, 2:56 AM PDTSmall Craft AdvisoryEKA5 days

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.