Alert archive / California / Special Weather Statements in 2017

Special Weather Statement, NWS Eureka, CA

August 8, 2017Trinity County, California

NWS Eureka, CA issued this special weather statement at Aug 8, 2017, 5:52 PM PDT for Trinity County, California. It was in force for 23 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 8, 2017, 5:52 PM PDT (00:52 UTC)
Expired: Aug 8, 2017, 6:15 PM PDT
In force: 23 min
Issued by: NWS Eureka, CA

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 89 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.

The nearest sounding before it

Medford/Jackson, OR (KMFR), launched 00:00Z, 0.9 hours before the alert went out and 190 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: 296 J/kg
Mixed-layer CIN: -66 J/kg
Mixed-layer LCL: 3444 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -5 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

927 
WWUS86 KEKA 090052
SPSEKA

Special Weather Statement
National Weather Service Eureka CA
552 PM PDT TUE AUG 8 2017

CAZ107-108-090115-
Southern Trinity-Northern Trinity-
552 PM PDT TUE AUG 8 2017

...A STRONG THUNDERSTORM WILL AFFECT WEST CENTRAL TRINITY COUNTY...

At 552 PM PDT, a strong thunderstorm was located near Big Bar, or 10
miles northwest of Hayfork, moving north at 10 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Hayfork, Big Bar and Del Loma. Highway 299.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4059 12327 4064 12339 4083 12341 4085 12313
      4067 12314
TIME...MOT...LOC 0052Z 169DEG 9KT 4067 12329 

$$

JMG/RCL

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 8, 5:26 PM PDT	Special Weather Statement	EKA	Trinity	34 min
Aug 8, 6:51 PM PDT	Special Weather Statement	EKA		24 min
Aug 8, 7:14 PM PDT	Special Weather Statement	EKA		31 min
Aug 9, 1:32 PM PDT	Special Weather Statement	EKA		43 min
Aug 9, 1:50 PM PDT	Severe Thunderstorm Warning	EKA	Mendocino, Trinity	23 min
Aug 9, 2:28 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	32 min
Aug 9, 2:34 PM PDT	Special Weather Statement	EKA	Mendocino	26 min
Aug 9, 2:40 PM PDT	Special Weather Statement	EKA	Trinity	35 min
Aug 9, 2:50 PM PDT	Severe Thunderstorm Warning	EKA	Mendocino	25 min
Aug 9, 2:52 PM PDT	Special Weather Statement	EKA	Trinity	23 min
Aug 9, 3:05 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	25 min
Aug 9, 3:10 PM PDT	Severe Thunderstorm Warning	EKA	Mendocino	35 min
Aug 9, 3:23 PM PDT	Special Weather Statement	EKA	Trinity	22 min
Aug 9, 3:43 PM PDT	Special Weather Statement	EKA	Mendocino	32 min
Aug 9, 3:47 PM PDT	Special Weather Statement	EKA	Trinity	28 min
Aug 9, 3:50 PM PDT	Special Weather Statement	EKA	Trinity	25 min
Aug 9, 4:09 PM PDT	Special Weather Statement	EKA	Mendocino	36 min
Aug 9, 4:12 PM PDT	Special Weather Statement	EKA	Trinity	33 min
Aug 9, 4:41 PM PDT	Special Weather Statement	EKA	Trinity	34 min

Nearby

Special Weather Statements in California, 2017 Every special weather statement 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.