Alert archive / California / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 2, NWS Eureka, CA

May 25, 2015Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at May 25, 2015, 5:20 PM PDT for Trinity County, California. It was in force for 25 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: May 25, 2015, 5:20 PM PDT (00:20 UTC)
Expired: May 25, 2015, 5:45 PM PDT
In force: 25 min
Issued by: NWS Eureka, CA
Area: Storm-based polygon

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 136 km from the middle of the area, began a volume at 00:23 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, 0.3 hours before the alert went out and 180 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2378 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: 35 m²/s²
0-3 km storm-relative helicity: 72 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

580 
WUUS56 KEKA 260020
SVREKA
CAC105-260045-
/O.NEW.KEKA.SV.W.0002.150526T0020Z-150526T0045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EUREKA
520 PM PDT MON MAY 25 2015

THE NATIONAL WEATHER SERVICE IN EUREKA CALIFORNIA HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL TRINITY COUNTY IN NORTHWESTERN CALIFORNIA...

* UNTIL 545 PM PDT

* AT 519 PM PDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS
  OF 60 MPH. THIS STORM WAS LOCATED 8 MILES NORTHWEST OF FRENCH 
  GULCH...OR 11 MILES NORTHEAST OF WEAVERVILLE...AND DRIFTING  
  SOUTHEAST AT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...
  LEWISTON.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS...DESTRUCTIVE HAIL...
DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR PROTECTION...MOVE TO
AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR HOME OR BUSINESS. HEAVY
RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE INTO AREAS WHERE WATER
COVERS THE ROAD.

TORRENTIAL RAINFALL IS ALSO OCCURRING WITH THIS STORM...AND MAY LEAD
TO FLASH FLOODING. DO NOT DRIVE YOUR VEHICLE THROUGH FLOODED
ROADWAYS.

&&

LAT...LON 4083 12267 4081 12266 4078 12267 4075 12272
      4073 12271 4071 12271 4069 12273 4069 12275
      4065 12273 4063 12271 4061 12271 4078 12289
      4092 12274 4087 12262
TIME...MOT...LOC 0019Z 309DEG 6KT 4080 12274 

$$

CARROLL

1 follow-up statement

797 
WWUS56 KEKA 260043
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EUREKA
543 PM PDT MON MAY 25 2015

CAC105-260052-
/O.EXP.KEKA.SV.W.0002.000000T0000Z-150526T0045Z/
TRINITY CA-
543 PM PDT MON MAY 25 2015

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL TRINITY COUNTY
WILL EXPIRE AT 545 PM PDT...
        
THE STORM WHICH PROMPTED THE WARNING IS MOVING OUT OF THE AREA. 
THEREFORE THE WARNING WILL BE ALLOWED TO EXPIRE. HOWEVER SMALL HAIL 
AND GUSTY WINDS ARE STILL POSSIBLE WITH THIS THUNDERSTORM. 
ADDITIONAL ISOLATED STORMS MAY DEVELOP OVER THE NEXT COUPLE OF HOURS.

LAT...LON 4083 12267 4081 12266 4078 12267 4075 12272
      4073 12271 4071 12271 4069 12273 4069 12275
      4065 12273 4063 12271 4061 12271 4078 12289
      4092 12274 4087 12262
TIME...MOT...LOC 0036Z 309DEG 6KT 4080 12274 

$$

CARROLL

The office that day

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

Issued	Product	Office	Counties	Lasted
May 25, 5:10 PM PDT	Special Weather Statement	EKA	Trinity	50 min

Nearby

Severe Thunderstorm Warnings in California, 2015 Every severe thunderstorm warning in 2015

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.