Alert archive / California / Freeze Warnings in 2017

Freeze Warning 9, NWS Eureka, CA

October 13, 2017Trinity County, California

NWS Eureka, CA issued this freeze warning at Oct 13, 2017, 12:55 PM PDT for Trinity County, California. It took effect at Oct 14, 2017, 1:00 AM PDT. It was in force for 8 hr. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Oct 13, 2017, 12:55 PM PDT (19:55 UTC)
In effect from
Oct 14, 2017, 1:00 AM PDT
Expired
Oct 14, 2017, 9:00 AM PDT
In force
8 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 19:56 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, 7.9 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 2017-10-13Temperature 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 2017-10-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 72 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
878 m above ground
0-6 km bulk shear
52 kt
0-1 km storm-relative helicity
72 m²/s²
0-3 km storm-relative helicity
105 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

577 
WWUS76 KEKA 131955
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
1255 PM PDT Fri Oct 13 2017

CAZ108-141600-
/O.NEW.KEKA.FZ.W.0009.171014T0800Z-171014T1600Z/
Southern Trinity-
1255 PM PDT Fri Oct 13 2017

...FREEZE WARNING IN EFFECT FROM 1 AM TO 9 AM PDT SATURDAY...

The National Weather Service in Eureka has issued a Freeze
Warning...which is in effect from 1 AM to 9 AM PDT Saturday. 

* LOW TEMPERATURES...Upper 20s to lower 30s.

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

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Freeze Warning means sub-freezing temperatures are imminent or
highly likely. These conditions will kill crops and other
sensitive vegetation.

&&

$$

CAZ102-105>107-110-111-141600-
/O.NEW.KEKA.FR.Y.0025.171014T0800Z-171014T1600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
1255 PM PDT Fri Oct 13 2017

...FROST ADVISORY IN EFFECT FROM 1 AM TO 9 AM PDT SATURDAY...

The National Weather Service in Eureka has issued a Frost
Advisory...which is in effect from 1 AM to 9 AM PDT Saturday. 

* LOW TEMPERATURES...Low to mid 30s.

* LOCATIONS INCLUDE...Gasquet...Orleans...Willow Creek...
  Garberville...Bridgeville...Weaverville...Burnt Ranch...Trinity
  Center...Leggett...Laytonville...Willits...Covelo...and other wind-
  sheltered valleys.

* 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
490 
WWUS76 KEKA 141601
NPWEKA

URGENT - WEATHER MESSAGE
National Weather Service Eureka CA
901 AM PDT Sat Oct 14 2017



CAZ108-141715-
/O.EXP.KEKA.FZ.W.0009.000000T0000Z-171014T1600Z/
Southern Trinity-
901 AM PDT Sat Oct 14 2017

...FREEZE WARNING HAS EXPIRED...

Temperatures will rapidly warm above freezing over the next hour.

$$

CAZ102-105>107-110-111-141715-
/O.EXP.KEKA.FR.Y.0025.000000T0000Z-171014T1600Z/
Del Norte Interior-Northern Humboldt Interior-
Southern Humboldt Interior-Northern Trinity-
Northwestern Mendocino Interior-Northeastern Mendocino Interior-
901 AM PDT Sat Oct 14 2017

...FROST ADVISORY HAS EXPIRED...

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 13, 11:18 AM PDTRed Flag WarningEKA34 hr
Oct 13, 12:55 PM PDTFrost AdvisoryEKADel Norte, Humboldt, Mendocino20 hr

Nearby

Freeze Warnings in California, 2017Every freeze warning 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.