Alert archive / Nevada / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 39, NWS Las Vegas, NV

August 20, 2012Clark County, Nevada

NWS Las Vegas, NV issued this severe thunderstorm warning at Aug 20, 2012, 3:33 PM PDT for Clark County, Nevada. It was in force for 17 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 20, 2012, 3:33 PM PDT (22:33 UTC)
Expired: Aug 20, 2012, 3:50 PM PDT
In force: 17 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon

County Clark County, NV

The radar

The Las Vegas radar (KESX), 41 km from the middle of the area, began a volume at 22:32 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

Las Vegas, NV (KVEF), launched 12:00Z, 10.6 hours before the alert went out and 54 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: 108 J/kg
Mixed-layer CIN: -337 J/kg
Mixed-layer LCL: 1666 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 30 m²/s²
0-3 km storm-relative helicity: 92 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

932 
WUUS55 KVEF 202233
SVRVEF
NVC003-202315-
/O.NEW.KVEF.SV.W.0039.120820T2233Z-120820T2315Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
333 PM PDT MON AUG 20 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...

* UNTIL 415 PM PDT.

* AT 328 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR SOUTHERN HIGHLANDS...OR 10
  MILES WEST OF HENDERSON...AND WAS MOVING EAST AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
  SEVEN HILLS AND SILVERADO RANCH.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS STORM IS CAPABLE OF PRODUCING DAMAGING WINDS WHICH CAN BRING
DOWN TREES AND POWER LINES AND CAUSE SIGNIFICANT BLOWING DUST AND
DEBRIS. IN ADDITION...HAIL AND LIGHTNING ARE LIKELY. LIGHTNING CAN
KILL! TAKE COVER IN A SUBSTANTIAL SHELTER AND STAY AWAY FROM WINDOWS
UNTIL THE STORM PASSES.

REPORT SEVERE WEATHER BY POSTING YOUR REPORT TO THE LAS VEGAS
NATIONAL WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER
HASHTAG...NWSVEGAS.

&&

LAT...LON 3604 11515 3597 11509 3595 11520 3599 11522
TIME...MOT...LOC 2233Z 248DEG 8KT 3599 11516

$$
KENNEDY

1 follow-up statement

426 
WWUS55 KVEF 202250
SVSVEF

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
350 PM PDT MON AUG 20 2012

NVC003-202254-
/O.CAN.KVEF.SV.W.0039.000000T0000Z-120820T2315Z/
CLARK NV-
350 PM PDT MON AUG 20 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL CLARK COUNTY IS
CANCELLED...

THE SEVERE THUNDERSTORM WHICH PROMPTED THE WARNING FOR SOUTHERN 
PORTIONS OF THE LAS VEGAS VALLEY INCLUDING SOUTHERN HIGHLANDS HAS 
WEAKENED...AND THEREFORE THE WARNING IS CANCELLED. THE HIGHEST WIND 
GUST ASSOCIATED WITH THE STORM WAS 59 MPH...WHICH WAS OBSERVED NEAR 
THE JUNCTION OF ST ROSE PARKWAY AND INTERSTATE 15.

REPORT SEVERE WEATHER BY POSTING YOUR REPORT TO THE LAS VEGAS
NATIONAL WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER 
HASHTAG...#NWSVEGAS.

LAT...LON 3604 11515 3597 11509 3595 11520 3599 11522
TIME...MOT...LOC 2244Z 248DEG 8KT 3600 11513

$$

KENNEDY

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 19, 9:21 PM PDT	Flash Flood Warning	VEF	Lincoln	114 min

Nearby

Severe Thunderstorm Warnings in Nevada, 2012 Every severe thunderstorm warning in 2012

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.