Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 69, NWS Las Vegas, NV

September 9, 2021San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 9, 2021, 1:47 PM PDT for San Bernardino County, California. It was in force for 58 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
Sep 9, 2021, 1:47 PM PDT (20:47 UTC)
Expired
Sep 9, 2021, 2:45 PM PDT
In force
58 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

County San Bernardino County, CA

The radar

The Edwards AFB radar (KEYX), 33 km from the middle of the area, began a volume at 20:46 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

Las Vegas, NV (KVEF), launched 12:00Z, 8.8 hours before the alert went out and 231 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, Las Vegas, NV at 12:00Z on 2021-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 353 joules per kilogram.LCLLFCEL10008507005003002001001 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, Las Vegas, NV at 12:00Z on 2021-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 27 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
353 J/kg
Mixed-layer CIN
-332 J/kg
Mixed-layer LCL
3002 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
27 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

948 
WUUS55 KVEF 092047
SVRVEF
CAC071-092145-
/O.NEW.KVEF.SV.W.0069.210909T2047Z-210909T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
147 PM PDT Thu Sep 9 2021

The National Weather Service in Las Vegas has issued a

* Severe Thunderstorm Warning for...
  West central San Bernardino County in southern California...

* Until 245 PM PDT.

* At 146 PM PDT, a severe thunderstorm was located 7 miles north of
  I-15 Between Victorville And Barstow, moving northwest at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs and trees.

* Locations impacted include...
  Barstow, I-15 Between Victorville And Barstow and Lenwood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3482 11761 3512 11717 3485 11703 3479 11712
TIME...MOT...LOC 2046Z 136DEG 9KT 3484 11721 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BKP
2 follow-up statements
429 
WWUS55 KVEF 092100
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
200 PM PDT Thu Sep 9 2021

CAC071-092145-
/O.CON.KVEF.SV.W.0069.000000T0000Z-210909T2145Z/
San Bernardino CA-
200 PM PDT Thu Sep 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 245 PM PDT
FOR WEST CENTRAL SAN BERNARDINO COUNTY...

At 200 PM PDT, a severe thunderstorm was located 14 miles northwest
of Barstow, moving northwest at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs and trees.

Locations impacted include...
Barstow, I-15 Between Victorville And Barstow and Lenwood. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3482 11761 3512 11717 3485 11703 3479 11712
TIME...MOT...LOC 2100Z 148DEG 39KT 3497 11729 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

BKP
862 
WWUS55 KVEF 092136
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
236 PM PDT Thu Sep 9 2021

CAC071-092146-
/O.EXP.KVEF.SV.W.0069.000000T0000Z-210909T2145Z/
San Bernardino CA-
236 PM PDT Thu Sep 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL SAN BERNARDINO
COUNTY WILL EXPIRE AT 245 PM PDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.

LAT...LON 3482 11761 3512 11717 3485 11703 3479 11712
TIME...MOT...LOC 2136Z 136DEG 9KT 3503 11737 

$$

BKP

The office that day

Everything else NWS Las Vegas, NV issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 9, 2:31 PM PDTSevere Thunderstorm WarningVEFSan Bernardino59 min

Nearby

Severe Thunderstorm Warnings in California, 2021Every severe thunderstorm warning in 2021

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.