Alert archive / California / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 12, NWS Eureka, CA

August 10, 2017Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at Aug 10, 2017, 4:30 PM PDT for Trinity County, California. It was in force for 30 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 10, 2017, 4:30 PM PDT (23:30 UTC)
Expired: Aug 10, 2017, 5:00 PM PDT
In force: 30 min
Issued by: NWS Eureka, CA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 87 km from the middle of the area, began a volume at 23:30 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 214 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 130 J/kg
Mixed-layer CIN: -439 J/kg
Mixed-layer LCL: 1837 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: -5 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.

261 
WUUS56 KEKA 102330
SVREKA
CAC105-110000-
/O.NEW.KEKA.SV.W.0012.170810T2330Z-170811T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Eureka CA
430 PM PDT THU AUG 10 2017

The National Weather Service in Eureka California has issued a

* Severe Thunderstorm Warning for...
  Central Trinity County in northwestern California...

* Until 500 PM PDT

* At 430 PM PDT, a severe thunderstorm was located near Peanut, or 9
  miles southwest of Hayfork, and is nearly stationary.

  HAZARD...Quarter size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Damage to vehicles is expected. 

* Locations impacted include...
  Hayfork and Peanut. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4051 12335 4057 12318 4041 12310 4039 12333
TIME...MOT...LOC 2330Z 330DEG 1KT 4046 12325 

HAIL...1.00IN
WIND...<50MPH
 
$$

RPA

1 follow-up statement

496 
WWUS56 KEKA 102353
SVSEKA

Severe Weather Statement
National Weather Service Eureka CA
453 PM PDT THU AUG 10 2017

CAC105-110003-
/O.EXP.KEKA.SV.W.0012.000000T0000Z-170811T0000Z/
Trinity CA-
453 PM PDT THU AUG 10 2017

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL TRINITY COUNTY WILL
EXPIRE AT 500 PM PDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Eureka California.

LAT...LON 4051 12335 4057 12318 4041 12310 4039 12333
TIME...MOT...LOC 2353Z 330DEG 1KT 4045 12325 

$$

GARNER

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 1:17 PM PDT	Special Weather Statement	EKA	Trinity	28 min
Aug 10, 1:57 PM PDT	Special Weather Statement	EKA	Trinity	33 min
Aug 10, 2:09 PM PDT	Special Weather Statement	EKA	Trinity	36 min
Aug 10, 2:26 PM PDT	Small Craft Advisory	EKA		8 days
Aug 10, 2:28 PM PDT	Special Weather Statement	EKA	Trinity	32 min
Aug 10, 2:43 PM PDT	Special Weather Statement	EKA	Trinity	32 min
Aug 10, 3:06 PM PDT	Special Weather Statement	EKA	Trinity	39 min
Aug 10, 3:28 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	32 min
Aug 10, 3:30 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	30 min
Aug 10, 3:53 PM PDT	Special Weather Statement	EKA	Trinity	37 min
Aug 10, 4:03 PM PDT	Special Weather Statement	EKA	Mendocino	42 min
Aug 10, 4:05 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	25 min
Aug 10, 4:08 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	37 min
Aug 10, 4:45 PM PDT	Areal Flood Advisory	EKA	Trinity	105 min
Aug 10, 4:48 PM PDT	Special Weather Statement	EKA	Humboldt	27 min
Aug 10, 4:52 PM PDT	Special Weather Statement	EKA	Trinity	23 min

Nearby

Severe Thunderstorm Warnings in California, 2017 Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.