Alert archive / California / Frost Advisories in 2017

Frost Advisory 18, NWS Eureka, CA

October 1, 2017Humboldt County, Trinity County, California

NWS Eureka, CA issued this frost advisory at Oct 1, 2017, 3:22 PM PDT for Humboldt County, Trinity County, California. It took effect at Oct 2, 2017, 12:00 AM PDT. It was in force for 8 hr.

The area

The counties it named.

The facts

Issued
Oct 1, 2017, 3:22 PM PDT (22:22 UTC)
In effect from
Oct 2, 2017, 12:00 AM PDT
Expired
Oct 2, 2017, 8:00 AM PDT
In force
8 hr
Issued by
NWS Eureka, CA

Counties Humboldt County, CA, Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 69 km from the middle of the area, began a volume at 22:24 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, 10.4 hours before the alert went out and 197 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 2017-10-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3 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 12:00Z on 2017-10-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -16 square meters per square second.1939587897117Sfc1 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
3 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
988 m above ground
0-6 km bulk shear
87 kt
0-1 km storm-relative helicity
-16 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

970 
WWUS76 KEKA 012222
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
322 PM PDT Sun Oct 1 2017

CAZ105>108-021500-
/O.NEW.KEKA.FR.Y.0018.171002T0700Z-171002T1500Z/
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-
322 PM PDT Sun Oct 1 2017

...FROST ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 8 AM 
MONDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from midnight tonight to 8 AM 
Monday. 

* LOCATIONS INCLUDE...Orleans...Willow Creek...Burnt
  Ranch...Hayfork.

* 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
522 
WWUS76 KEKA 020914
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
214 AM PDT Mon Oct 2 2017

CAZ105>108-021500-
/O.CON.KEKA.FR.Y.0018.000000T0000Z-171002T1500Z/
Northern Humboldt Interior-Southern Humboldt Interior-
Northern Trinity-Southern Trinity-
214 AM PDT Mon Oct 2 2017

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

* LOCATIONS INCLUDE...Hayfork...Ruth...Orleans...Willow
  Creek...Weaverville...Burnt Ranch...Trinity Center...
  Garberville...Bridgeville.

* 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
Oct 1, 3:05 AM PDTFire Weather WatchEKA30 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.