Alert archive / California / Severe Thunderstorm Warnings in 2015

Severe Thunderstorm Warning 1, NWS Eureka, CA

May 25, 2015Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at May 25, 2015, 4:29 PM PDT for Trinity County, California. It was in force for 31 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, 4:29 PM PDT (23:29 UTC)
Expired
May 25, 2015, 5:00 PM PDT
In force
31 min
Issued by
NWS Eureka, CA
Area
Storm-based polygon

County Trinity County, CA

The radar

The Medford radar (KMAX), 138 km from the middle of the area, began a volume at 23:31 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, 11.5 hours before the alert went out and 171 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 2015-05-25Temperature 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 2015-05-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 8 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
1001 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
8 m²/s²
0-3 km storm-relative helicity
8 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.

640 
WUUS56 KEKA 252329
SVREKA
CAC105-260000-
/O.NEW.KEKA.SV.W.0001.150525T2329Z-150526T0000Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE EUREKA
429 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 500 PM PDT

* AT 428 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 7 MILES SOUTH OF TRINITY 
  CENTER...AND DRIFTING SOUTH AT 5 MPH.

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 4089 12260 4088 12263 4085 12264 4083 12267
      4081 12266 4078 12267 4075 12272 4073 12271
      4072 12271 4078 12295 4097 12280 4092 12261
      4091 12260
TIME...MOT...LOC 2328Z 019DEG 5KT 4088 12272 

$$

CARROLL
1 follow-up statement
104 
WWUS56 KEKA 252352
SVSEKA

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

CAC105-260000-
/O.CON.KEKA.SV.W.0001.000000T0000Z-150526T0000Z/
TRINITY CA-
452 PM PDT MON MAY 25 2015

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 500 PM PDT
FOR EAST CENTRAL TRINITY COUNTY...

AT 450 PM PDT...DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM 
CAPABLE OF PRODUCING QUARTER SIZE HAIL AND DAMAGING WINDS IN EXCESS 
OF 60 MPH. THIS STORM IS SLOWLY WEAKENING AND WAS LOCATED 9 MILES 
SOUTH OF TRINITY CENTER...DRIFTING SOUTH AT 5 MPH.

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 4089 12260 4088 12263 4085 12264 4083 12267
      4081 12266 4078 12267 4075 12272 4073 12271
      4072 12271 4078 12295 4097 12280 4092 12261
      4091 12260
TIME...MOT...LOC 2350Z 019DEG 5KT 4085 12273 

$$

CARROLL

The office that day

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

IssuedProductOfficeCountiesLasted
May 25, 2:44 PM PDTSpecial Weather StatementEKATrinity31 min
May 25, 4:19 PM PDTSpecial Weather StatementEKATrinity26 min
May 25, 4:34 PM PDTAreal Flood AdvisoryEKATrinity116 min

Nearby

Severe Thunderstorm Warnings in California, 2015Every 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.