Alert archive / California / Frost Advisories in 2017

Frost Advisory 10, NWS Eureka, CA

April 28, 2017Trinity County, California

NWS Eureka, CA issued this frost advisory at Apr 28, 2017, 5:12 AM PDT for Trinity County, California. It was in force for 3 hr.

The area

The counties it named.

The facts

Issued
Apr 28, 2017, 5:12 AM PDT (12:12 UTC)
Expired
Apr 28, 2017, 8:00 AM PDT
In force
3 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 12:18 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, 0.2 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 12:00Z on 2017-04-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 joules per kilogram.LCLLFCEL10008507005003002001001 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 12:00Z on 2017-04-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 square meters per square second.1939587897117136156Sfc1 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
1 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1005 m above ground
0-6 km bulk shear
90 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
83 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

133 
WWUS76 KEKA 281212
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
512 AM PDT Fri Apr 28 2017

CAZ107-108-281500-
/O.NEW.KEKA.FR.Y.0010.170428T1212Z-170428T1500Z/
Northern Trinity-Southern Trinity-
512 AM PDT Fri Apr 28 2017

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

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect until 8 AM PDT this morning. 

* LOCATIONS INCLUDE...Weaverville...Burnt Ranch...Trinity
  Center...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
470 
WWUS76 KEKA 281508
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
808 AM PDT Fri Apr 28 2017

CAZ107-108-281615-
/O.EXP.KEKA.FR.Y.0010.000000T0000Z-170428T1500Z/
Northern Trinity-Southern Trinity-
808 AM PDT Fri Apr 28 2017

...FROST ADVISORY HAS EXPIRED...

$$

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.