Alert archive / California / Severe Thunderstorm Warnings in 2023

Severe Thunderstorm Warning 2, NWS Eureka, CA

August 18, 2023Trinity County, California

NWS Eureka, CA issued this severe thunderstorm warning at Aug 18, 2023, 4:51 PM PDT for Trinity County, California. It was in force for 24 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 18, 2023, 4:51 PM PDT (23:51 UTC)
Expired: Aug 18, 2023, 5:15 PM PDT
In force: 24 min
Issued by: NWS Eureka, CA
Area: Storm-based polygon
Hail: 1.0 in
Wind: 50.0 mph

County Trinity County, CA

The radar

The Eureka (Bunker Hill) radar (KBHX), 113 km from the middle of the area, began a volume at 23:54 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 243 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: 81 J/kg
Mixed-layer CIN: -329 J/kg
Mixed-layer LCL: 2123 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: -8 m²/s²
0-3 km storm-relative helicity: -33 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

691 
WUUS56 KEKA 182351
SVREKA
CAC105-190015-
/O.NEW.KEKA.SV.W.0002.230818T2351Z-230819T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Eureka CA
451 PM PDT Fri Aug 18 2023

The National Weather Service in Eureka California has issued a

* Severe Thunderstorm Warning for...
  South central Trinity County in northwestern California...

* Until 515 PM PDT.

* At 450 PM PDT, a severe thunderstorm was located 9 miles west of
  Saddle Camp, or 15 miles south of Yolla Bolly District Rs, and is
  nearly stationary.

  HAZARD...Quarter size hail. Gusty winds up to 45 mph.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* This severe thunderstorm will remain over mainly rural areas of
  south central Trinity County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4007 12307 4030 12319 4033 12307 4029 12307
      4027 12305 4026 12302 4024 12298 4018 12297
      4017 12299 4014 12299 4014 12297 4012 12297
      4009 12296
TIME...MOT...LOC 2350Z 328DEG 4KT 4014 12298 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...<50 MPH

$$

EYS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 5:33 PM PDT	Special Weather Statement	EKA	Trinity	27 min
Aug 17, 6:49 PM PDT	Special Weather Statement	EKA	Trinity	26 min
Aug 17, 7:33 PM PDT	Special Weather Statement	EKA	Trinity	27 min
Aug 17, 8:19 PM PDT	Special Weather Statement	EKA	Trinity	26 min
Aug 18, 2:26 AM PDT	Hazardous Seas Warning	EKA		42 hr

Nearby

Severe Thunderstorm Warnings in California, 2023 Every severe thunderstorm warning in 2023

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.