Alert archive / California / Special Weather Statements in 2017

Special Weather Statement, NWS Eureka, CA

August 6, 2017

NWS Eureka, CA issued this special weather statement at Aug 6, 2017, 5:28 PM PDT. It was in force for 32 min. 2 reports 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: Aug 6, 2017, 5:28 PM PDT (00:28 UTC)
Expired: Aug 6, 2017, 6:00 PM PDT
In force: 32 min
Issued by: NWS Eureka, CA

The radar

The Medford radar (KMAX), 117 km from the middle of the area, began a volume at 00:31 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

Time	Report	Where	Remark
Aug 6, 5:30 PM PDT	HAIL 1	2 Sse Carrville, CA	MARBLE TO QUARTER SIZE HAIL REPORTED BY TRAINED SPOTTER. TIME AND LOCATION APPROXIMATE. LOCALLY HEAVY RAIN AS WELL.
Aug 6, 5:55 PM PDT	HAIL 0.25	1 S Trinity Center, CA	PEA SIZED HAIL REPORTED BY CAMPGROUND PERSONNEL. TIME ESTIMATED FROM RADAR.

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, 0.5 hours before the alert went out and 149 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: 7 J/kg
Mixed-layer CIN: -207 J/kg
Mixed-layer LCL: 3615 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: 16 m²/s²
0-3 km storm-relative helicity: 39 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

373 
WWUS86 KEKA 070028
SPSEKA

Special Weather Statement
National Weather Service Eureka CA
528 PM PDT SUN AUG 6 2017

CAZ107-070100-
Northern Trinity-
528 PM PDT SUN AUG 6 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN TRINITY COUNTY...

At 526 PM PDT, a strong thunderstorm was located near Carrville and 
Trinity Center , or 24 miles southwest of Mount Shasta, moving 
southwest at 10 mph.

Winds in excess of 30 mph and nickel size hail are possible with this
storm.

Locations impacted include...
Carrville...Trinity Center and Highway 3.

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.

If you are on or near Trinity Lake, get out of the water and move 
indoors or inside a vehicle. Remember, lightning can strike out to 
10 miles from the parent thunderstorm. If you can hear thunder, you 
are close enough to be struck by lightning. Move to safe shelter 
now! Do not be caught on the water in a thunderstorm.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

LAT...LON 4108 12252 4107 12254 4106 12254 4106 12252
      4101 12253 4100 12254 4100 12255 4099 12257
      4099 12259 4096 12261 4093 12261 4100 12289
      4118 12274 4113 12251
TIME...MOT...LOC 0026Z 037DEG 10KT 4110 12267 

$$

RCL

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 5:32 PM PDT	Severe Thunderstorm Warning	EKA	Trinity	28 min
Aug 6, 6:08 PM PDT	Special Weather Statement	EKA		22 min
Aug 6, 11:36 PM PDT	Red Flag Warning	EKA		20 hr
Aug 7, 3:43 PM PDT	Special Weather Statement	EKA	Trinity	32 min
Aug 7, 3:50 PM PDT	Special Weather Statement	EKA	Trinity	25 min
Aug 7, 3:57 PM PDT	Special Weather Statement	EKA		33 min
Aug 7, 3:59 PM PDT	Special Weather Statement	EKA	Trinity	16 min
Aug 7, 4:07 PM PDT	Special Weather Statement	EKA	Trinity	8 min
Aug 7, 4:28 PM PDT	Special Weather Statement	EKA		32 min
Aug 7, 4:40 PM PDT	Special Weather Statement	EKA	Trinity	35 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.