Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 59, NWS Las Vegas, NV

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

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 12, 2021, 8:17 PM MST for Mohave County, Arizona; Clark County, Nevada. It was in force for 58 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, 8:17 PM MST (03:17 UTC)
Expired: Aug 12, 2021, 9:15 PM MST
In force: 58 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Mohave County, AZ, Clark County, NV

The radar

The Las Vegas radar (KESX), 55 km from the middle of the area, began a volume at 03:20 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 MST	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, 3.3 hours before the alert went out and 68 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.

136 
WUUS55 KVEF 130317
SVRVEF
AZC015-NVC003-130415-
/O.NEW.KVEF.SV.W.0059.210813T0317Z-210813T0415Z/

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

The National Weather Service in Las Vegas has issued a

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

* Until 915 PM PDT/915 PM MST/.

* At 816 PM PDT/816 PM MST/, a severe thunderstorm was located 10
  miles north of Callville Bay Campground, or 12 miles east of The
  Motor Speedway, moving south at 45 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...
  Henderson, North Las Vegas, Boulder City, Las Vegas Bay, Lake Las
  Vegas, Nellis AFB, East Las Vegas, Sam Boyd Stadium, The Motor
  Speedway, Boulder Beach, Railroad Pass, Boulder Beach Campground,
  Las Vegas Bay Campground, Callville Bay, Hoover Dam, Callville Bay
  Campground, Sunrise Mtn and Frenchman Mtn.

This includes Interstate 15 in Nevada between mile markers 60 and 63.
 
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 3636 11500 3637 11450 3609 11437 3596 11473
      3598 11500 3625 11508
TIME...MOT...LOC 0316Z 005DEG 40KT 3628 11479 

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

$$

CO

1 follow-up statement

329 
WWUS55 KVEF 130347
SVSVEF

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

AZC015-NVC003-130415-
/O.CON.KVEF.SV.W.0059.000000T0000Z-210813T0415Z/
Mohave AZ-Clark NV-
847 PM PDT Thu Aug 12 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM
PDT/915 PM MST/ FOR WEST CENTRAL MOHAVE AND CENTRAL CLARK COUNTIES...

At 845 PM PDT/845 PM MST/, a severe thunderstorm was located over 
Lake Las Vegas, moving south at 25 mph.  Wind gusts over 50 mph are 
likely on the western side of Lake Mead and near Callville bay.

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...
Henderson, North Las Vegas, Boulder City, Las Vegas Bay, Lake Las
Vegas, Nellis AFB, East Las Vegas, Sam Boyd Stadium, The Motor
Speedway, Boulder Beach, Railroad Pass, Boulder Beach Campground, Las
Vegas Bay Campground, Callville Bay, Hoover Dam, Callville Bay
Campground, Sunrise Mtn and Frenchman Mtn.

This includes Interstate 15 in Nevada between mile markers 60 and 63.
 
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 3636 11500 3637 11450 3609 11437 3596 11473
      3598 11500 3625 11508
TIME...MOT...LOC 0345Z 005DEG 40KT 3595 11483 

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

$$

CO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 5:24 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	111 min
Aug 12, 5:43 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 8:42 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 8:54 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 9:10 PM MST	Severe Thunderstorm Warning	VEF	Mohave	50 min
Aug 12, 10:56 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 7:06 PM MST	Severe Thunderstorm Warning	VEF	Clark	39 min
Aug 12, 7:40 PM MST	Severe Thunderstorm Warning	VEF	Clark	50 min
Aug 12, 7:46 PM MST	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Aug 13, 2:37 AM MST	Excessive Heat Watch	VEF	Clark, Nye	12 hr
Aug 13, 2:18 PM MST	Excessive Heat Warning	VEF	Clark, Nye	3 days
Aug 13, 2:23 PM MST	Severe Thunderstorm Warning	VEF	Clark	52 min

Nearby

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