Alert archive / California / Special Weather Statements in 2017

Special Weather Statement, NWS Eureka, CA

September 8, 2017Trinity County, California

NWS Eureka, CA issued this special weather statement at Sep 8, 2017, 3:21 PM PDT for Trinity County, California. It was in force for 24 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
Sep 8, 2017, 3:21 PM PDT (22:21 UTC)
Expired
Sep 8, 2017, 3:45 PM PDT
In force
24 min
Issued by
NWS Eureka, CA

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 113 km from the middle of the area, began a volume at 22:22 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, 10.4 hours before the alert went out and 213 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 2017-09-08Temperature 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 2017-09-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 21 square meters per square second.1939Sfc1 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
790 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
21 m²/s²
0-3 km storm-relative helicity
119 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

310 
WWUS86 KEKA 082221
SPSEKA

Special Weather Statement
National Weather Service Eureka CA
321 PM PDT FRI SEP 8 2017
 
CAZ107-108-082245-
Southern Trinity CA-Northern Trinity CA-
321 PM PDT FRI SEP 8 2017

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TRINITY COUNTY UNTIL 345
PM PDT...

At 321 PM PDT, Doppler radar was tracking a strong thunderstorm near
Knob, or 7 miles northwest of Yolla Bolly District Rs, moving north
at 10 mph.

Dime size hail will be possible with this storm.

Locations impacted include...
Hayfork.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4048 12286 4047 12288 4045 12290 4045 12293
      4043 12294 4042 12295 4042 12300 4040 12300
      4038 12302 4040 12316 4064 12316 4058 12281
TIME...MOT...LOC 2221Z 191DEG 7KT 4046 12303 

$$

Nearby

Special Weather Statements in California, 2017Every 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.