Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 53, NWS Las Vegas, NV

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

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 10, 2021, 5:13 PM PDT for San Bernardino County, California; Mohave County, Arizona. It was in force for 92 min. 4 reports 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 10, 2021, 5:13 PM PDT (00:13 UTC)
Expired
Aug 10, 2021, 6:45 PM PDT
In force
92 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), 169 km from the middle of the area, began a volume at 00:18 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 10, 6:10 PM PDTTSTM WND DMG2 Nnw Lake Havasu City, AZSHINGLES BLOWN OFF ROOF NEAR N PALO VERDE BLVD AND AVALON AVE.
Aug 10, 6:15 PM PDTTSTM WND DMG1 Nnw Lake Havasu City, AZNUMEROUS SHINGLES BLOWN OFF A HOME NEAR ALPINE DR. AND HAVASUPAI BLVD.
Aug 10, 6:15 PM PDTTSTM WND DMG1 Sw Lake Havasu City, AZSEVERAL LARGE TREES DOWN NEAR SMOKETREE AVE AND MCCULLOCH BLVD.
Aug 10, 6:17 PM PDTTSTM WND GST 592 Wsw Lake Havasu City, AZWIND MEASURED NEAR LONDON BRIDGE IN LAKE HAVASU. DATA COURTESY OF EARTH NETWORKS.

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

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 0.2 hours before the alert went out and 222 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, Phoenix, AZ at 00:00Z on 2021-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 934 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, Phoenix, AZ at 00:00Z on 2021-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 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
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.

192 
WUUS55 KVEF 110013
SVRVEF
AZC015-CAC071-110145-
/O.NEW.KVEF.SV.W.0053.210811T0013Z-210811T0145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
513 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 645 PM PDT/645 PM MST/.

* At 509 PM PDT/509 PM MST/, severe thunderstorms were located along 
  a line extending from near Oatman to 11 miles south of Yucca to 
  the south to the La Paz County Line, moving southwest at 25 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,
  Alamo Lake, Needles, Three Dunes Campground, Alamo State Park,
  Desert Hills, Black Meadow Landing Campground, Mohave Valley,
  Cattail Cove State Park, Arizona Village, Earp, Vidal Junction, Big
  River, Mesquite Creek, Mojave Ranch Estates and Willow Valley.

This includes the following highways...
 Interstate 40 in Arizona between mile markers 0 and 17.
 Interstate 40 in California between mile markers 140 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 3503 11450 3471 11412 3447 11375
      3430 11354 3423 11360 3421 11367 3421 11370
      3424 11373 3422 11384 3426 11386 3425 11401
      3430 11409 3430 11414 3426 11413 3426 11416
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0009Z 033DEG 22KT 3497 11446 3470 11414 3446 11377
3422 11347

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

$$

SC
3 follow-up statements
628 
WWUS55 KVEF 110035
SVSVEF

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

AZC015-CAC071-110145-
/O.CON.KVEF.SV.W.0053.000000T0000Z-210811T0145Z/
Mohave AZ-San Bernardino CA-
535 PM PDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM
PDT/645 PM MST/ FOR SOUTHWESTERN MOHAVE AND SOUTHEASTERN SAN
BERNARDINO COUNTIES...

At 534 PM PDT/534 PM MST/, severe thunderstorms were located along a
line extending from near Arizona Village to 6 miles northeast of Lake
Havasu City to 14 miles east of Parker Dam to 13 miles south of Alamo
State Park, 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,
Alamo Lake, Needles, Three Dunes Campground, Alamo State Park, Desert
Hills, Black Meadow Landing Campground, Mohave Valley, Cattail Cove
State Park, Arizona Village, Earp, Vidal Junction, Big River,
Mesquite Creek, Mojave Ranch Estates and Willow Valley.

This includes the following highways...
 Interstate 40 in Arizona between mile markers 0 and 17.
 Interstate 40 in California between mile markers 140 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 3503 11450 3471 11412 3447 11375
      3430 11354 3423 11360 3421 11367 3421 11370
      3424 11373 3422 11384 3426 11386 3425 11401
      3430 11409 3430 11414 3426 11413 3426 11416
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0034Z 034DEG 26KT 3486 11454 3458 11423 3435 11389
3406 11359

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

$$

SC
425 
WWUS55 KVEF 110059
SVSVEF

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

AZC015-CAC071-110145-
/O.CON.KVEF.SV.W.0053.000000T0000Z-210811T0145Z/
Mohave AZ-San Bernardino CA-
559 PM PDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM
PDT/645 PM MST/ FOR SOUTHWESTERN MOHAVE AND SOUTHEASTERN SAN
BERNARDINO COUNTIES...

At 557 PM PDT/557 PM MST/, severe thunderstorms were located along a 
line extending from near Arizona Village to Desert Hills to 2 miles 
east of Lake Havasu City to near Parker Dam, moving southwest at 25 
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,
Alamo Lake, Needles, Three Dunes Campground, Alamo State Park, Desert
Hills, Black Meadow Landing Campground, Mohave Valley, Cattail Cove
State Park, Arizona Village, Earp, Vidal Junction, Big River,
Mesquite Creek, Mojave Ranch Estates and Willow Valley.

This includes the following highways...
 Interstate 40 in Arizona between mile markers 0 and 17.
 Interstate 40 in California between mile markers 140 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 3503 11450 3471 11412 3447 11375
      3430 11354 3423 11360 3421 11367 3421 11370
      3424 11373 3422 11384 3426 11386 3425 11401
      3430 11409 3430 11414 3426 11413 3426 11416
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0057Z 044DEG 22KT 3483 11453 3455 11437 3432 11410
3418 11391

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

$$

SC
187 
WWUS55 KVEF 110131
SVSVEF

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

AZC015-CAC071-110145-
/O.CON.KVEF.SV.W.0053.000000T0000Z-210811T0145Z/
Mohave AZ-San Bernardino CA-
631 PM PDT Tue Aug 10 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 645 PM
PDT/645 PM MST/ FOR SOUTHWESTERN MOHAVE AND SOUTHEASTERN SAN
BERNARDINO COUNTIES...

At 628 PM PDT/628 PM MST/, severe thunderstorms were located along a 
line extending from 8 miles south of Needles to 4 miles west of Lake 
Havasu City to near Parker, moving southwest at 25 mph.

HAZARD...60 mph wind gusts and near zero visibility due to blowing 
         dust.

SOURCE...Wind speeds of 59 mph have been observed in Lake Havasu 
         City.

IMPACT...Expect damage to roofs and trees.

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

This includes the following highways...
 Interstate 40 in Arizona between mile markers 0 and 17.
 Interstate 40 in California between mile markers 140 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 3503 11450 3471 11412 3447 11375
      3430 11354 3423 11360 3421 11367 3421 11370
      3424 11373 3422 11384 3426 11386 3425 11401
      3430 11409 3430 11414 3426 11413 3426 11416
      3419 11423 3411 11441 3408 11444 3408 11462
TIME...MOT...LOC 0128Z 033DEG 22KT 3469 11464 3441 11448 3418 11421
3404 11402

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

$$

SC

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 10, 5:49 PM PDTDust Storm WarningVEFSan Bernardino56 min
Aug 10, 6:43 PM PDTSevere Thunderstorm WarningVEFSan Bernardino47 min
Aug 10, 6:55 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr
Aug 10, 11:22 PM PDTFlash Flood Warning Considerable damage threatVEFSan Bernardino3 hr

Nearby

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