Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 63, NWS Las Vegas, NV

August 13, 2021San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 13, 2021, 4:04 PM PDT for San Bernardino County, California. It was in force for 41 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 13, 2021, 4:04 PM PDT (23:04 UTC)
Expired
Aug 13, 2021, 4:45 PM PDT
In force
41 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), 83 km from the middle of the area, began a volume at 23:05 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.

What was reported inside it

TimeReportWhereRemark
Aug 13, 4:22 PM PDTTSTM WND GST 609 Sse Cima, CAPEAK WIND GUST OF 60 MPH ASSOCIATED WITH A THUNDERSTORM AT APPROXIMATELY 422 PM MEASURED AT MID HILLS CA. SUSTAINED WINDS WITH THE OBSERVATION WERE 7 MPH FROM THE WNW.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 11.1 hours before the alert went out and 137 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.

330 
WUUS55 KVEF 132304
SVRVEF
CAC071-132345-
/O.NEW.KVEF.SV.W.0063.210813T2304Z-210813T2345Z/

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

The National Weather Service in Las Vegas has issued a

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

* Until 445 PM PDT.

* At 403 PM PDT, a severe thunderstorm was located over Mid Hills
  Campground, or near Cima, moving southwest at 15 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.

* Locations impacted include...
  Cima, Kelso, Mitchell Caverns, Mid Hills Campground, Black Canyon
  Equestrian Campground and Hole In The Wall Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3543 11547 3508 11514 3487 11533 3481 11564
      3522 11596
TIME...MOT...LOC 2303Z 051DEG 14KT 3515 11545 

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

$$
DSB
2 follow-up statements
003 
WWUS55 KVEF 132326
SVSVEF

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

CAC071-132345-
/O.CON.KVEF.SV.W.0063.000000T0000Z-210813T2345Z/
San Bernardino CA-
426 PM PDT Fri Aug 13 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM PDT
FOR CENTRAL SAN BERNARDINO COUNTY...

At 426 PM PDT, a severe thunderstorm was located near Mid Hills
Campground, or 8 miles northeast of Kelso, moving southwest at 15
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.

Locations impacted include...
Cima, Kelso, Mitchell Caverns, Mid Hills Campground, Black Canyon
Equestrian Campground and Hole In The Wall Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3543 11547 3508 11514 3487 11533 3481 11564
      3522 11596
TIME...MOT...LOC 2326Z 051DEG 14KT 3509 11554 

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

$$

DSB
945 
WWUS55 KVEF 132340
SVSVEF

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

CAC071-132350-
/O.EXP.KVEF.SV.W.0063.000000T0000Z-210813T2345Z/
San Bernardino CA-
440 PM PDT Fri Aug 13 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 445 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.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 3543 11547 3508 11514 3487 11533 3481 11564
      3522 11596
TIME...MOT...LOC 2340Z 051DEG 14KT 3506 11559 

$$
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, 3:20 PM PDTSevere Thunderstorm WarningVEFSan Bernardino40 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.