Alert archive / California / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 1, NWS Eureka, CA

February 5, 2017Humboldt County, California

NWS Eureka, CA issued this severe thunderstorm warning at Feb 5, 2017, 4:54 PM PST for Humboldt County, California. It was in force for 36 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Feb 5, 2017, 4:54 PM PST (00:54 UTC)
Expired
Feb 5, 2017, 5:30 PM PST
In force
36 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon

County Humboldt County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 19 km from the middle of the area, began a volume at 00:54 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.

What was reported inside it

TimeReportWhereRemark
Feb 5, 5:08 PM PSTTSTM WND GST 604 S Petrolia, CACOOSKIE MOUNTAIN RAWS, ELEVATION 2945 FEET. PEAK WIND GUST FOR THE HOURLY OBSERVATION ENDING AT 508 PM.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 00:00Z, 0.9 hours before the alert went out and 259 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 2017-02-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 00:00Z on 2017-02-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -3 square meters per square second.1939587897Sfc1 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
17 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1930 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
-3 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

517 
WUUS56 KEKA 060054
SVREKA
CAC023-060130-
/O.NEW.KEKA.SV.W.0001.170206T0054Z-170206T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Eureka CA
454 PM PST SUN FEB 5 2017

The National Weather Service in Eureka California has issued a

* Severe Thunderstorm Warning for...
  Southwestern Humboldt County in northwestern California...

* Until 530 PM PST

* At 453 PM PST, Doppler radar indicated a line of severe
  thunderstorms capable of producing damaging winds in excess of 60 
  mph. These storms were located along a line extending from 5 miles 
  west Cape Mendocino to 20 miles west of Shelter Cove, and moving 
  northeast at 45 mph.

* Locations impacted include...
  Petrolia and Capetown. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe thunderstorms produce damaging winds, destructive hail, deadly
lightning and very heavy rain. For your protection, move to an
interior room on the lowest floor of your home or business. Heavy
rains flood roads quickly so do not drive into areas where water
covers the road.

Torrential rainfall is also occurring with these storms, and may lead
to flash flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4050 12442 4051 12439 4040 12419 4011 12409
      4000 12419 4029 12441
TIME...MOT...LOC 0053Z 206DEG 40KT 4045 12450 4015 12445 3982 12446 

$$

BC
1 follow-up statement
524 
WWUS56 KEKA 060119
SVSEKA

Severe Weather Statement
National Weather Service Eureka CA
519 PM PST SUN FEB 5 2017

CAC023-060130-
/O.CON.KEKA.SV.W.0001.000000T0000Z-170206T0130Z/
Humboldt CA-
519 PM PST SUN FEB 5 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM PST
FOR SOUTHWESTERN HUMBOLDT COUNTY...

At 517 PM PST, Doppler radar indicated severe thunderstorms capable
of producing damaging winds in excess of 60 mph. These storms were 
located along a line extending from 8 miles southwest of Fortuna, 
through Petrolia to 14 miles southwest of Honeydew, moving northeast 
at 40 mph.

Locations impacted include...
Petrolia and Capetown. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Severe thunderstorms produce damaging winds, destructive hail, deadly
lightning and very heavy rain. For your protection move to an
interior room on the lowest floor of your home or business. Heavy
rains flood roads quickly so do not drive into areas where water
covers the road.

Torrential rainfall is also occurring with these storms, and may lead
to flash flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4050 12441 4051 12439 4040 12419 4021 12418
      4015 12424 4029 12441
TIME...MOT...LOC 0117Z 209DEG 35KT 4052 12430 4037 12427 4013 12437 

$$

BC

The office that day

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

IssuedProductOfficeCountiesLasted
Feb 5, 5:11 PM PSTSpecial Weather StatementEKAHumboldt34 min
Feb 5, 5:38 PM PSTSpecial Weather StatementEKAHumboldt37 min
Feb 5, 10:26 PM PSTCoastal Flood AdvisoryEKAHumboldt11 hr
Feb 6, 2:57 AM PSTSmall Craft AdvisoryEKA6 hr
Feb 6, 9:36 AM PSTGale WarningEKA23 hr
Feb 6, 9:38 AM PSTWind AdvisoryEKAHumboldt, Mendocino, Trinity25 hr
Feb 6, 10:45 AM PSTFlood WatchEKAHumboldt, Mendocino, Trinity20 hr
Feb 6, 2:45 PM PSTSmall Craft AdvisoryEKA37 hr
Feb 6, 3:19 PM PSTHigh Wind WatchEKADel Norte, Humboldt, Trinity23 hr
Feb 6, 3:20 PM PSTRiver Flood WatchEKAHumboldt18 hr
Feb 6, 3:20 PM PSTRiver Flood WatchEKAMendocino14 hr
Feb 6, 3:32 PM PSTRiver Flood AdvisoryEKAMendocino36 hr

Nearby

Severe Thunderstorm Warnings in California, 2017Every severe thunderstorm 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.