Alert archive / California / Special Weather Statements in 2017

Special Weather Statement, NWS Eureka, CA

August 7, 2017Trinity County, California

NWS Eureka, CA issued this special weather statement at Aug 7, 2017, 3:59 PM PDT for Trinity County, California. It was in force for 16 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 7, 2017, 3:59 PM PDT (22:59 UTC)
Expired
Aug 7, 2017, 4:15 PM PDT
In force
16 min
Issued by
NWS Eureka, CA

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 79 km from the middle of the area, began a volume at 23:01 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, 11.0 hours before the alert went out and 196 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 2017-08-07Temperature 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 2017-08-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
2184 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
11 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.

248 
WWUS86 KEKA 072259
SPSEKA

Special Weather Statement
National Weather Service Eureka CA
359 PM PDT MON AUG 7 2017

CAZ108-072315-
Southern Trinity-
359 PM PDT MON AUG 7 2017

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

At 358 PM PDT, a strong thunderstorm was located near Hyampom, or 12
miles northwest of Hayfork, moving south at 10 mph.

Winds in excess of 30 mph and half inch hail are possible with this
storm.

Locations impacted include...
Hyampom.

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.

LAT...LON 4051 12337 4055 12354 4072 12345 4073 12343
      4074 12342 4074 12340 4072 12330 4069 12327
      4068 12327
TIME...MOT...LOC 2258Z 012DEG 8KT 4067 12335 

$$

MKK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 5:28 PM PDTSpecial Weather StatementEKA32 min
Aug 6, 5:32 PM PDTSevere Thunderstorm WarningEKATrinity28 min
Aug 6, 6:08 PM PDTSpecial Weather StatementEKA22 min
Aug 6, 11:36 PM PDTRed Flag WarningEKA20 hr
Aug 7, 3:43 PM PDTSpecial Weather StatementEKATrinity32 min
Aug 7, 3:50 PM PDTSpecial Weather StatementEKATrinity25 min
Aug 7, 3:57 PM PDTSpecial Weather StatementEKA33 min
Aug 7, 4:07 PM PDTSpecial Weather StatementEKATrinity8 min
Aug 7, 4:28 PM PDTSpecial Weather StatementEKA32 min
Aug 7, 4:40 PM PDTSpecial Weather StatementEKATrinity35 min

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.