Alert archive / Nevada / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 60, NWS Las Vegas, NV

August 12, 2021Clark County, Nevada; Mohave County, Arizona

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 12, 2021, 9:10 PM PDT for Clark County, Nevada; Mohave County, Arizona. It was in force for 50 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 12, 2021, 9:10 PM PDT (04:10 UTC)
Expired: Aug 12, 2021, 10:00 PM PDT
In force: 50 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Mohave County, AZ, Clark County, NV

The radar

The Las Vegas radar (KESX), 28 km from the middle of the area, began a volume at 04:08 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

Time	Report	Where	Remark
Aug 12, 9:15 PM PDT	TSTM WND GST 63	2 Nw Hoover Dam, NV	PEAK WIND GUST OF 63 MPH REPORTED AT 915 PM WITH THUNDERSTORM AT BOULDER ISLAND. SUSTAINED WIND WITH THE OB WAS 30 MPH OUT OF THE NORTH.

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 00:00Z, 4.2 hours before the alert went out and 81 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: 1235 J/kg
Mixed-layer CIN: -41 J/kg
Mixed-layer LCL: 2944 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 2 m²/s²
0-3 km storm-relative helicity: 96 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

086 
WUUS55 KVEF 130410
SVRVEF
AZC015-NVC003-130500-
/O.NEW.KVEF.SV.W.0060.210813T0410Z-210813T0500Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
910 PM PDT Thu Aug 12 2021

The National Weather Service in Las Vegas has issued a

* Severe Thunderstorm Warning for...
  Northwestern Mohave County in northwestern Arizona...
  Central Clark County in southern Nevada...

* Until 1000 PM PDT/1000 PM MST/.

* At 909 PM PDT/909 PM MST/, a severe thunderstorm was located near
  Callville Bay, or near Las Vegas Bay, moving south at 20 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs and trees.

* Locations impacted include...
  Henderson, Boulder City, Las Vegas Bay, Lake Las Vegas, Boulder
  Beach, Railroad Pass, Boulder Beach Campground, Las Vegas Bay
  Campground, Callville Bay, Hoover Dam, Callville Bay Campground,
  Black Mtn and Willow Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Lake Mead, get away from the water and move indoors or 
inside a vehicle. Remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 3615 11497 3622 11461 3576 11445 3561 11473
      3577 11511
TIME...MOT...LOC 0409Z 346DEG 16KT 3611 11477 

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

$$

CO

2 follow-up statements

421 
WWUS55 KVEF 130430
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
930 PM PDT Thu Aug 12 2021

AZC015-NVC003-130500-
/O.CON.KVEF.SV.W.0060.000000T0000Z-210813T0500Z/
Mohave AZ-Clark NV-
930 PM PDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1000 PM
PDT/1000 PM MST/ FOR NORTHWESTERN MOHAVE AND CENTRAL CLARK
COUNTIES...

At 930 PM PDT/930 PM MST/, a severe thunderstorm was located over 
Hoover Dam, or near Boulder City, moving south at 20 mph. Strong 
wind gusts to 60 mph remain possible as well frequent cloud to 
ground lightning. 

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs and trees.

Locations impacted include...
Henderson, Boulder City, Las Vegas Bay, Lake Las Vegas, Boulder
Beach, Railroad Pass, Boulder Beach Campground, Las Vegas Bay
Campground, Callville Bay, Hoover Dam, Callville Bay Campground,
Black Mtn and Willow Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Lake Mead, get away from the water and move indoors or 
inside a vehicle. remember, lightning can strike out to 15 miles 
from the parent thunderstorm. If you can hear thunder, you are close 
enough to be struck by lightning. Move to safe shelter now!  Do not 
be caught on the water in a thunderstorm.

&&

LAT...LON 3615 11497 3622 11461 3576 11445 3561 11473
      3577 11511
TIME...MOT...LOC 0430Z 346DEG 16KT 3602 11474 

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

$$

CO

554 
WWUS55 KVEF 130455
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
955 PM PDT Thu Aug 12 2021

AZC015-NVC003-130505-
/O.EXP.KVEF.SV.W.0060.000000T0000Z-210813T0500Z/
Mohave AZ-Clark NV-
955 PM PDT Thu Aug 12 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN MOHAVE AND
CENTRAL CLARK COUNTIES WILL EXPIRE AT 1000 PM PDT/1000 PM MST/...
                
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 gusty
winds are still possible with this thunderstorm.

LAT...LON 3615 11497 3622 11461 3576 11445 3561 11473
      3577 11511
TIME...MOT...LOC 0455Z 346DEG 16KT 3592 11471 

$$

CO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 7:06 PM PDT	Severe Thunderstorm Warning	VEF	Clark	39 min
Aug 12, 7:40 PM PDT	Severe Thunderstorm Warning	VEF	Clark	50 min
Aug 12, 7:46 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Aug 12, 8:17 PM PDT	Severe Thunderstorm Warning	VEF	Clark	58 min
Aug 12, 8:42 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Aug 13, 2:37 AM PDT	Excessive Heat Watch	VEF	Clark, Nye	12 hr
Aug 13, 2:18 PM PDT	Excessive Heat Warning	VEF	Clark, Nye	3 days
Aug 13, 2:23 PM PDT	Severe Thunderstorm Warning	VEF	Clark	52 min
Aug 12, 5:24 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Mohave	111 min
Aug 12, 5:43 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 8:54 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 10:56 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr

Nearby

Severe Thunderstorm Warnings in Nevada, 2021 Severe Thunderstorm Warnings in Arizona, 2021 Every 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.