Alert archive / California / Frost Advisories in 2017

Frost Advisory 17, NWS Eureka, CA

September 24, 2017Trinity County, California

NWS Eureka, CA issued this frost advisory at Sep 24, 2017, 4:22 AM PDT for Trinity County, California. It was in force for 5 hr.

The area

The counties it named.

The facts

Issued
Sep 24, 2017, 4:22 AM PDT (11:22 UTC)
Expired
Sep 24, 2017, 9:00 AM PDT
In force
5 hr
Issued by
NWS Eureka, CA

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 101 km from the middle of the area, began a volume at 11:23 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, 11.4 hours before the alert went out and 193 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 2017-09-24Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 00:00Z on 2017-09-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
1974 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
82 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

362 
WWUS76 KEKA 241122
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
422 AM PDT Sun Sep 24 2017

CAZ108-241600-
/O.NEW.KEKA.FR.Y.0017.170924T1122Z-170924T1600Z/
Southern Trinity-
422 AM PDT Sun Sep 24 2017

...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. 

* TEMPERATURES...33 to 36 degrees.

* LOCATIONS INCLUDE...Hayfork...Ruth.

* 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
724 
WWUS76 KEKA 241601
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
901 AM PDT Sun Sep 24 2017

CAZ108-241715-
/O.EXP.KEKA.FR.Y.0017.000000T0000Z-170924T1600Z/
Southern Trinity-
901 AM PDT Sun Sep 24 2017

...FROST ADVISORY HAS EXPIRED...

Temperatures have warmed and the frost advisory has been allowed
to expire.

$$

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.