Alert archive / California / Severe Thunderstorm Warnings in 2013

Severe Thunderstorm Warning 10, NWS Eureka, CA

August 21, 2013Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at Aug 21, 2013, 2:56 PM PDT for Trinity County, California. It was in force for 49 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 21, 2013, 2:56 PM PDT (21:56 UTC)
Expired
Aug 21, 2013, 3:45 PM PDT
In force
49 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 80 km from the middle of the area, began a volume at 21:59 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, 9.9 hours before the alert went out and 232 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 2013-08-21Temperature 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°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 2013-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2413 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

386 
WUUS56 KEKA 212156
SVREKA
CAC105-212245-
/O.NEW.KEKA.SV.W.0010.130821T2156Z-130821T2245Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EUREKA CA
256 PM PDT WED AUG 21 2013

THE NATIONAL WEATHER SERVICE HAS ISSUED A

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

* UNTIL 345 PM PDT

* AT 248 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE HAIL.  THIS
  STORM WAS LOCATED NEAR RUTH...OR 21 MILES WEST OF YOLLA BOLLY
  DISTRICT RS...AND MOVING NORTHWEST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  FOREST GLEN

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4024 12320 4018 12337 4035 12355 4044 12354
      4051 12337
TIME...MOT...LOC 2156Z 153DEG 11KT 4029 12335

$$

MS
2 follow-up statements
359 
WWUS56 KEKA 212229
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EUREKA CA
329 PM PDT WED AUG 21 2013

CAC105-212245-
/O.CON.KEKA.SV.W.0010.000000T0000Z-130821T2245Z/
TRINITY CA-
329 PM PDT WED AUG 21 2013

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 345 PM PDT
FOR TRINITY COUNTY...

AT 321 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING QUARTER SIZE
HAIL.  THIS STORM WAS LOCATED NEAR FOREST GLEN...OR 23 MILES WEST OF
YOLLA BOLLY DISTRICT RS...MOVING NORTHWEST AT 15 MPH.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY FOR DAMAGING WINDS...DESTRUCTIVE HAIL...AND DEADLY CLOUD
TO GROUND LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...
PREFERABLY INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

&&

LAT...LON 4022 12335 4035 12355 4043 12354 4044 12353
      4051 12337 4039 12330 4026 12325
TIME...MOT...LOC 2230Z 153DEG 11KT 4038 12341

$$

MS
268 
WWUS56 KEKA 212242
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EUREKA CA
342 PM PDT WED AUG 21 2013

CAC105-212252-
/O.EXP.KEKA.SV.W.0010.000000T0000Z-130821T2245Z/
TRINITY CA-
342 PM PDT WED AUG 21 2013

...THE SEVERE THUNDERSTORM WARNING FOR TRINITY COUNTY WILL EXPIRE AT
345 PM PDT...

LAT...LON 4022 12335 4035 12355 4043 12354 4044 12353
      4051 12337 4039 12330 4026 12325
TIME...MOT...LOC 2242Z 153DEG 11KT 4041 12343

$$

MS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 3:09 AM PDTSmall Craft AdvisoryEKA12 hr
Aug 21, 1:18 PM PDTSpecial Weather StatementEKATrinity42 min
Aug 21, 1:59 PM PDTSpecial Weather StatementEKAHumboldt46 min
Aug 21, 2:22 PM PDTSevere Thunderstorm WarningEKAHumboldt, Trinity38 min
Aug 21, 2:40 PM PDTSpecial Weather StatementEKATrinity50 min
Aug 21, 4:18 PM PDTSpecial Weather StatementEKADel Norte42 min
Aug 21, 4:33 PM PDTSpecial Weather StatementEKATrinity27 min

Nearby

Severe Thunderstorm Warnings in California, 2013Every severe thunderstorm warning in 2013

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.