Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 54, NWS Las Vegas, NV

August 10, 2021Mohave County, Arizona; San Bernardino County, California

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 10, 2021, 6:43 PM MST for Mohave County, Arizona; San Bernardino County, California. It was in force for 47 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 10, 2021, 6:43 PM MST (01:43 UTC)
Expired: Aug 10, 2021, 7:30 PM MST
In force: 47 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Mohave County, AZ, San Bernardino County, CA

The radar

The Las Vegas radar (KESX), 158 km from the middle of the area, began a volume at 01:47 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

Phoenix, AZ (KPSR), launched 00:00Z, 1.7 hours before the alert went out and 247 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: 934 J/kg
Mixed-layer CIN: -17 J/kg
Mixed-layer LCL: 1571 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: -19 m²/s²
0-3 km storm-relative helicity: 0 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

193 
WUUS55 KVEF 110143
SVRVEF
AZC015-CAC071-110230-
/O.NEW.KVEF.SV.W.0054.210811T0143Z-210811T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
643 PM PDT Tue Aug 10 2021

The National Weather Service in Las Vegas has issued a

* Severe Thunderstorm Warning for...
  Southwestern Mohave County in northwestern Arizona...
  Southeastern San Bernardino County in southern California...

* Until 730 PM PDT/730 PM MST/.

* At 641 PM PDT/641 PM MST/, severe thunderstorms were located along 
  a line extending from 17 miles southwest of Needles to near Big 
  River, moving southwest at 30 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs and trees.

* Locations impacted include...
  Lake Havasu City, Highway 95 At Mile Marker 29, Topock, Parker Dam,
  Needles, Three Dunes Campground, Desert Hills, Black Meadow Landing
  Campground, Cattail Cove State Park, Arizona Village, Earp, Vidal
  Junction, Big River, Mohave Valley, Mesquite Creek and Willow
  Valley.

This includes the following highways...
 Interstate 40 in Arizona between mile markers 0 and 6.
 Interstate 40 in California between mile markers 141 and 155.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Lake Havasu, 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 3446 11506 3496 11456 3460 11428 3438 11401
      3430 11414 3426 11413 3426 11416 3420 11423
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0141Z 041DEG 25KT 3462 11483 3434 11466 3412 11439
3398 11420

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

$$

SC

2 follow-up statements

923 
WWUS55 KVEF 110203
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
703 PM PDT Tue Aug 10 2021

AZC015-110209-
/O.CAN.KVEF.SV.W.0054.000000T0000Z-210811T0230Z/
Mohave AZ-
703 PM PDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN MOHAVE COUNTY IS
CANCELLED...

The storms which prompted the warning have moved out of Mohave 
County. Therefore, the warning has been cancelled.

LAT...LON 3446 11506 3479 11469 3447 11443 3431 11419
      3430 11414 3427 11416 3426 11416 3420 11423
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0159Z 041DEG 25KT 3455 11491 3427 11474 3405 11447
3391 11428

$$

CAC071-110230-
/O.CON.KVEF.SV.W.0054.000000T0000Z-210811T0230Z/
San Bernardino CA-
703 PM PDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 730 PM PDT
FOR SOUTHEASTERN SAN BERNARDINO COUNTY...

At 659 PM PDT, severe thunderstorms were located along a line
extending from 16 miles northwest of Highway 95 At Mile Marker 29 to
10 miles northwest of Vidal Junction to 8 miles southwest of Big
River to 14 miles west of Bouse, moving southwest at 30 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs and trees.

Locations impacted include...
Highway 95 At Mile Marker 29, Earp, Vidal Junction and Big River. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

If on or near Lake Havasu, 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 3446 11506 3479 11469 3447 11443 3431 11419
      3430 11414 3427 11416 3426 11416 3420 11423
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0159Z 041DEG 25KT 3455 11491 3427 11474 3405 11447
3391 11428

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

$$

SC

096 
WWUS55 KVEF 110223
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
723 PM PDT Tue Aug 10 2021

CAC071-110231-
/O.EXP.KVEF.SV.W.0054.000000T0000Z-210811T0230Z/
San Bernardino CA-
723 PM PDT Tue Aug 10 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SAN BERNARDINO
COUNTY WILL EXPIRE AT 730 PM PDT...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning will 
be allowed to expire. However, thunderstorms continue to produce 
heavy rainfall and a Flash Flood Warning remains in effect for 
southeast San Bernardino County, primarily along Highway 95 south of 
Needles.

LAT...LON 3446 11506 3479 11469 3447 11443 3431 11419
      3430 11414 3427 11416 3426 11416 3420 11423
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0221Z 041DEG 25KT 3455 11491 3427 11474 3405 11447
3391 11428

$$

SC

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 5:13 PM MST	Severe Thunderstorm Warning	VEF	Mohave	92 min
Aug 10, 5:49 PM MST	Dust Storm Warning	VEF	Mohave	56 min
Aug 10, 6:55 PM MST	Flash Flood Warning Considerable damage threat	VEF	San Bernardino	3 hr
Aug 10, 11:22 PM MST	Flash Flood Warning Considerable damage threat	VEF	San Bernardino	3 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2021 Severe Thunderstorm Warnings in California, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.