Alert archive / California / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 4, NWS Eureka, CA

July 8, 2015Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at Jul 8, 2015, 5:50 PM PDT for Trinity County, California. It was in force for 40 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: Jul 8, 2015, 5:50 PM PDT (00:50 UTC)
Expired: Jul 8, 2015, 6:30 PM PDT
In force: 40 min
Issued by: NWS Eureka, CA
Area: Storm-based polygon

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 88 km from the middle of the area, began a volume at 00:52 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, 0.8 hours before the alert went out and 201 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: 347 J/kg
Mixed-layer CIN: -149 J/kg
Mixed-layer LCL: 1398 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 4 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, in the capitals the NWS used until 2016.

587 
WUUS56 KEKA 090050
SVREKA
CAC105-090130-
/O.NEW.KEKA.SV.W.0004.150709T0050Z-150709T0130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EUREKA
550 PM PDT WED JUL 8 2015

THE NATIONAL WEATHER SERVICE IN EUREKA CALIFORNIA HAS ISSUED A

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

* UNTIL 630 PM PDT

* AT 549 PM PDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM
  CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS 
  STORM WAS LOCATED OVER HAYFORK...AND MOVING NORTHWEST AT 15 MPH. 
  NICKEL SIZE HAIL MAY ALSO ACCOMPANY THE DAMAGING WINDS.

* LOCATIONS IMPACTED INCLUDE...
  HAYFORK AND HYAMPOM. 

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.

&&

LAT...LON 4063 12303 4048 12316 4050 12354 4074 12354
TIME...MOT...LOC 0049Z 121DEG 18KT 4060 12318 

$$

CARROLL

1 follow-up statement

695 
WWUS56 KEKA 090118
SVSEKA

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE EUREKA
618 PM PDT WED JUL 8 2015

CAC105-090130-
/O.CON.KEKA.SV.W.0004.000000T0000Z-150709T0130Z/
TRINITY CA-
618 PM PDT WED JUL 8 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 630 PM PDT
FOR WEST CENTRAL TRINITY COUNTY...

AT 617 PM...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM CAPABLE OF 
PRODUCING DAMAGING WINDS IN EXCESS OF 60 MPH. THIS STORM WAS LOCATED 
NEAR BIG BAR...OR 12 MILES NORTHWEST OF HAYFORK...DRIFTING NORTHWEST 
AT 5 MPH.

LOCATIONS IMPACTED INCLUDE...
HAYFORK.

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.

&&

LAT...LON 4063 12303 4048 12316 4049 12339 4070 12336
TIME...MOT...LOC 0117Z 121DEG 18KT 4067 12334 

$$

CARROLL

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 8, 5:14 PM PDT	Special Weather Statement	EKA	Trinity	46 min
Jul 8, 5:23 PM PDT	Special Weather Statement	EKA	Trinity	22 min
Jul 8, 6:01 PM PDT	Special Weather Statement	EKA	Trinity	44 min
Jul 8, 6:50 PM PDT	Special Weather Statement	EKA	Trinity	25 min
Jul 8, 6:52 PM PDT	Special Weather Statement	EKA	Trinity	23 min
Jul 8, 8:53 PM PDT	Areal Flood Advisory	EKA	Trinity	52 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.