Alert archive / California / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 39, NWS Las Vegas, NV

September 2, 2017San Bernardino County, California; Clark County, Nevada; Mohave County, Arizona

NWS Las Vegas, NV issued this severe thunderstorm warning at Sep 2, 2017, 6:58 PM PDT for San Bernardino County, California; Clark County, Nevada; Mohave County, Arizona. It was in force for 47 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
Sep 2, 2017, 6:58 PM PDT (01:58 UTC)
Expired
Sep 2, 2017, 7:45 PM PDT
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, Clark County, NV

The radar

The Las Vegas radar (KESX), 29 km from the middle of the area, began a volume at 02:00 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
Sep 2, 7:31 PM PDTTSTM WND DMGCottonwood Cove, NV*** 1 FATAL *** LAKE MEAD DISPATCH CENTER REPORTED A DEATH CAUSED BY CONDITIONS BROUGHT ABOUT FROM THE HIGH WINDS ASSOCIATED WITH SEVERE THUNDERSTORM ACTIVITY. AN ADULT MALE BECAME ENTANGLED IN THE MOORING LINE OF A HOUSE BOAT THAT BROKE LOOSE DURING HIGH WIND

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, 2.0 hours before the alert went out and 124 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 00:00Z on 2017-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 326 joules per kilogram.LCLEL10008507005003002001001 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 00:00Z on 2017-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
326 J/kg
Mixed-layer CIN
-11 J/kg
Mixed-layer LCL
3748 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
5 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

895 
WUUS55 KVEF 030158
SVRVEF
AZC015-CAC071-NVC003-030245-
/O.NEW.KVEF.SV.W.0039.170903T0158Z-170903T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Las Vegas NV
658 PM PDT SAT SEP 2 2017

The National Weather Service in Las Vegas has issued a

* Severe Thunderstorm Warning for...
  West central Mohave County in northwestern Arizona...
  Eastern San Bernardino County in southern California...
  South central Clark County in southern Nevada...

* Until 745 PM PDT/745 PM MST/

* At 654 PM PDT/654 PM MST/, outflow from a severe thunderstorm was 
  located 12 miles east of Cottonwood Cove, or 19 miles north of 
  Laughlin, moving west at 30 mph. Strong winds are expected on Lake 
  Mohave by 715 PM.

  HAZARD...50 to 60 mph wind gusts. 

  SOURCE...Radar indicated. 

  IMPACT...Dangerous boating conditions due to strong winds. 

* Locations impacted include...
  Lake Mohave, Laughlin, Katherine Landing, Cottonwood Cove, 
  Cottonwood Cove Campground, Big Bend Rec Area, Mohave Valley and 
  Willow Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If on or near Lake Mohave, 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 3589 11464 3502 11449 3499 11464 3588 11479
TIME...MOT...LOC 0154Z 091DEG 24KT 3543 11448 

HAIL...<.75IN
WIND...60MPH
 
$$

JS
2 follow-up statements
831 
WWUS55 KVEF 030227
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
727 PM PDT SAT SEP 2 2017

AZC015-CAC071-NVC003-030245-
/O.CON.KVEF.SV.W.0039.000000T0000Z-170903T0245Z/
Mohave AZ-San Bernardino CA-Clark NV-
727 PM PDT SAT SEP 2 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 745 PM
PDT/745 PM MST/ FOR WEST CENTRAL MOHAVE...EASTERN SAN BERNARDINO AND
SOUTH CENTRAL CLARK COUNTIES...

At 724 PM PDT/724 PM MST/, an outflow boundary generated by 
thunderstorms over west central Mohave County was pushing across the 
Colorado River Valley, including Lake Mohave, at around 715 PM and 
continued to move west at 30 mph.

HAZARD...50 to 60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...Dangerous boating conditions due to strong winds. 

Locations impacted include...
Lake Mohave, Bullhead City, Laughlin, Katherine Landing, Cottonwood 
Cove, Cottonwood Cove Campground, Big Bend Rec Area, Mohave Valley 
and Willow Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If on or near Lake Mohave, 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 3589 11464 3502 11449 3499 11464 3588 11479
TIME...MOT...LOC 0224Z 091DEG 24KT 3543 11473 

HAIL...<.75IN
WIND...60MPH
 
$$

JS
606 
WWUS55 KVEF 030250
SVSVEF

Severe Weather Statement
National Weather Service Las Vegas NV
750 PM PDT SAT SEP 2 2017

AZC015-CAC071-NVC003-030257-
/O.EXP.KVEF.SV.W.0039.000000T0000Z-170903T0245Z/
Mohave AZ-San Bernardino CA-Clark NV-
750 PM PDT SAT SEP 2 2017

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL MOHAVE...EASTERN
SAN BERNARDINO AND SOUTH CENTRAL CLARK COUNTIES HAS EXPIRED...
                
The outflow from thunderstorms which prompted the warning has moved 
west of the warned area however, strong gusty winds 40 to 50 MPH are 
still likely along the Colorado River Valley through 815 PM.

LAT...LON 3589 11464 3502 11449 3499 11464 3588 11479
TIME...MOT...LOC 0247Z 091DEG 24KT 3543 11490 

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 3, 3:18 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Sep 3, 4:24 PM PDTFlash Flood WarningVEFInyo3 hr
Sep 2, 6:14 PM PDTAreal Flood AdvisoryVEFMohave3 hr
Sep 2, 6:18 PM PDTSevere Thunderstorm WarningVEFMohave42 min
Sep 3, 2:42 PM PDTSevere Thunderstorm WarningVEFMohave24 min
Sep 3, 4:45 PM PDTAreal Flood AdvisoryVEFMohave3 hr

Nearby

Severe Thunderstorm Warnings in California, 2017Severe Thunderstorm Warnings in Nevada, 2017Severe Thunderstorm Warnings in Arizona, 2017Every severe thunderstorm warning in 2017

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.