Alert archive / California / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 5, NWS Eureka, CA

August 5, 2012Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at Aug 5, 2012, 4:31 PM PDT for Trinity County, California. It was in force for 29 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 5, 2012, 4:31 PM PDT (23:31 UTC)
Expired
Aug 5, 2012, 5:00 PM PDT
In force
29 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 82 km from the middle of the area, began a volume at 23:33 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, 11.5 hours before the alert went out and 184 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 2012-08-05Temperature 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 2012-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -51 square meters per square second.193958Sfc1 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
-793 J/kg
Mixed-layer LCL
2407 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-51 m²/s²
0-3 km storm-relative helicity
96 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

358 
WUUS56 KEKA 052331
SVREKA
CAC105-060000-
/O.NEW.KEKA.SV.W.0005.120805T2331Z-120806T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE
431 PM PDT SUN AUG 5 2012

THE NATIONAL WEATHER SERVICE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  TRINITY COUNTY IN NORTHWEST CALIFORNIA...

* UNTIL 500 PM PDT

* AT 429 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL...AND
  DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS LOCATED 7 MILES
  SOUTH OF DEL LOMA...OR 22 MILES WEST OF WEAVERVILLE...AND MOVING
  NORTH AT 10 MPH.

* THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL
  AREAS OF THE INDICATED COUNTY.

LAT...LON 4083 12347 4087 12331 4067 12330 4065 12337
TIME...MOT...LOC 2331Z 163DEG 9KT 4069 12336

$$

BFG
2 follow-up statements
338 
WWUS56 KEKA 052346
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE
446 PM PDT SUN AUG 5 2012

CAC105-060000-
/O.CON.KEKA.SV.W.0005.000000T0000Z-120806T0000Z/
TRINITY CA-
446 PM PDT SUN AUG 5 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM PDT
FOR TRINITY COUNTY...

AT 442 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL...AND DAMAGING WINDS IN EXCESS OF 60 MPH.  THIS STORM WAS
LOCATED OVER TRINITY COUNTY...OR 21 MILES SOUTHEAST OF WILLOW
CREEK...MOVING NORTH AT 10 MPH.

THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS
OF THE INDICATED COUNTY.

LAT...LON 4071 12334 4070 12338 4083 12345 4086 12335
TIME...MOT...LOC 2346Z 163DEG 9KT 4073 12337

$$

BFG
912 
WWUS56 KEKA 060000
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE
500 PM PDT SUN AUG 5 2012

CAC105-060010-
/O.EXP.KEKA.SV.W.0005.000000T0000Z-120806T0000Z/
TRINITY CA-
500 PM PDT SUN AUG 5 2012

...THE SEVERE THUNDERSTORM WARNING FOR TRINITY COUNTY HAS EXPIRED...

LAT...LON 4071 12334 4070 12338 4083 12345 4086 12335
TIME...MOT...LOC 0000Z 163DEG 9KT 4076 12338

$$

BFG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 5, 3:22 PM PDTSpecial Weather StatementEKATrinity38 min
Aug 5, 3:26 PM PDTSevere Thunderstorm WarningEKAHumboldt, Trinity34 min
Aug 5, 3:58 PM PDTSevere Thunderstorm WarningEKATrinity16 min
Aug 5, 4:18 PM PDTSevere Thunderstorm WarningEKATrinity27 min

Nearby

Severe Thunderstorm Warnings in California, 2012Every severe thunderstorm warning in 2012

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.