Alert archive / California / Special Weather Statements in 2017

Special Weather Statement, NWS Eureka, CA

August 6, 2017Trinity County, California

NWS Eureka, CA issued this special weather statement at Aug 6, 2017, 4:53 PM PDT for Trinity County, California. It was in force for 22 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 6, 2017, 4:53 PM PDT (23:53 UTC)
Expired
Aug 6, 2017, 5:15 PM PDT
In force
22 min
Issued by
NWS Eureka, CA

County Trinity County, CA

The radar

The Medford radar (KMAX), 120 km from the middle of the area, began a volume at 23:57 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, 11.9 hours before the alert went out and 151 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 2017-08-06Temperature 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°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Medford/Jackson, OR at 12:00Z on 2017-08-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 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
2593 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
54 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

307 
WWUS86 KEKA 062353
SPSEKA

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

CAZ107-070015-
Northern Trinity-
453 PM PDT SUN AUG 6 2017

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

At 452 PM PDT, a strong thunderstorm was located 15 miles north of
Helena, or 18 miles north of Weaverville. the storm is nearly
stationary.

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

This storm will remain over mainly rural areas of central Northern
Trinity County.

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.

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

LAT...LON 4090 12289 4088 12313 4107 12322 4108 12314
      4107 12311 4105 12306 4100 12304 4101 12298
      4101 12296 4099 12294 4099 12292 4103 12290
      4107 12292 4108 12297 4111 12297 4112 12287
TIME...MOT...LOC 2352Z 157DEG 3KT 4098 12304 

$$

MKK

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 6, 2:18 PM PDTSpecial Weather StatementEKATrinity12 min
Aug 6, 2:33 PM PDTSpecial Weather StatementEKATrinity12 min
Aug 6, 2:48 PM PDTSpecial Weather StatementEKA12 min
Aug 6, 2:54 PM PDTSpecial Weather StatementEKATrinity21 min
Aug 6, 2:58 PM PDTSpecial Weather StatementEKATrinity17 min
Aug 6, 3:08 PM PDTSpecial Weather StatementEKATrinity22 min
Aug 6, 3:16 PM PDTSpecial Weather StatementEKAGlenn14 min
Aug 6, 3:32 PM PDTSpecial Weather StatementEKATrinity13 min
Aug 6, 3:37 PM PDTSpecial Weather StatementEKA8 min
Aug 6, 3:49 PM PDTSpecial Weather StatementEKATrinity11 min
Aug 6, 4:04 PM PDTSpecial Weather StatementEKASiskiyou26 min
Aug 6, 4:16 PM PDTSpecial Weather StatementEKATrinity14 min
Aug 6, 4:39 PM PDTSpecial Weather StatementEKASiskiyou21 min
Aug 6, 4:57 PM PDTSpecial Weather StatementEKASiskiyou33 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.