Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 62, NWS Las Vegas, NV

August 13, 2021San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 13, 2021, 3:20 PM PDT for San Bernardino 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
Aug 13, 2021, 3:20 PM PDT (22:20 UTC)
Expired
Aug 13, 2021, 4:00 PM PDT
In force
40 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Hail
1.0 in
Wind
60.0 mph

County San Bernardino County, CA

The radar

The Las Vegas radar (KESX), 65 km from the middle of the area, began a volume at 22:21 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, 10.3 hours before the alert went out and 135 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 2021-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 487 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 2021-08-13The 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
487 J/kg
Mixed-layer CIN
-323 J/kg
Mixed-layer LCL
2453 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
80 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

499 
WUUS55 KVEF 132220
SVRVEF
CAC071-132300-
/O.NEW.KVEF.SV.W.0062.210813T2220Z-210813T2300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
320 PM PDT Fri Aug 13 2021

The National Weather Service in Las Vegas has issued a

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

* Until 400 PM PDT.

* At 320 PM PDT, a severe thunderstorm was located 13 miles northeast
  of Mid Hills Campground, or 14 miles east of Cima, moving southeast
  at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs and trees.

* This severe thunderstorm will remain over mainly rural areas of
  northeastern San Bernardino County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

&&

LAT...LON 3528 11539 3542 11517 3518 11487 3490 11517
      3508 11539
TIME...MOT...LOC 2220Z 328DEG 18KT 3525 11524 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DSB
2 follow-up statements
296 
WWUS55 KVEF 132246
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
346 PM PDT Fri Aug 13 2021

CAC071-132300-
/O.CON.KVEF.SV.W.0062.000000T0000Z-210813T2300Z/
San Bernardino CA-
346 PM PDT Fri Aug 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM PDT
FOR NORTHEASTERN SAN BERNARDINO COUNTY...

At 345 PM PDT, a severe thunderstorm was located 13 miles west of
Highway 95 And I-40, or 22 miles southwest of Laughlin, moving
southeast at 20 mph.

HAZARD...60 mph wind gusts and quarter size hail.

SOURCE...Radar indicated.

IMPACT...Hail damage to vehicles is expected. Expect wind damage to 
         roofs and trees.

This severe thunderstorm will remain over mainly rural areas of
northeastern San Bernardino County.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move to a shelter, inside a strong building and away from
windows.

&&

LAT...LON 3528 11539 3542 11517 3518 11487 3490 11517
      3508 11539
TIME...MOT...LOC 2245Z 328DEG 18KT 3494 11500 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

DSB
908 
WWUS55 KVEF 132259
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
359 PM PDT Fri Aug 13 2021

CAC071-132309-
/O.EXP.KVEF.SV.W.0062.000000T0000Z-210813T2300Z/
San Bernardino CA-
359 PM PDT Fri Aug 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN SAN BERNARDINO
COUNTY WILL EXPIRE AT 400 PM PDT...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 3528 11539 3542 11517 3518 11487 3490 11517
      3508 11539
TIME...MOT...LOC 2259Z 328DEG 18KT 3489 11496 

$$

DSB

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 13, 2:37 AM PDTExcessive Heat WatchVEFInyo, San Bernardino12 hr
Aug 13, 2:18 PM PDTExcessive Heat WarningVEFInyo, San Bernardino3 days
Aug 13, 2:23 PM PDTSevere Thunderstorm WarningVEFSan Bernardino52 min
Aug 13, 2:46 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 13, 4:04 PM PDTSevere Thunderstorm WarningVEFSan Bernardino41 min
Aug 13, 4:55 PM PDTSevere Thunderstorm WarningVEFSan Bernardino50 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.