Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 139, NWS Las Vegas, NV

August 21, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 21, 2012, 1:19 PM PDT for Clark County, Nevada. It was in force for 116 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 21, 2012, 1:19 PM PDT (20:19 UTC)
Expired
Aug 21, 2012, 3:15 PM PDT
In force
116 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 119 km from the middle of the area, began a volume at 20:21 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, 8.3 hours before the alert went out and 70 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 12:00Z on 2012-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 108 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, Las Vegas, NV at 12:00Z on 2012-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 20 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
108 J/kg
Mixed-layer CIN
-245 J/kg
Mixed-layer LCL
2596 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
20 m²/s²
0-3 km storm-relative helicity
-46 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.

348 
WGUS55 KVEF 212019
FFWVEF
NVC003-212215-
/O.NEW.KVEF.FF.W.0139.120821T2019Z-120821T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
119 PM PDT TUE AUG 21 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTH CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...

* UNTIL 315 PM PDT.

* AT 112 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR COYOTE SPRINGS...OR 20
  MILES NORTHWEST OF MOAPA. THE STORM PRODUCING VERY HEAVY RAIN 
  WAS MOVING NORTHEAST AT ABOUT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...
  COYOTE SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO CROSS A FLOODED
ROADWAY OR WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

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

&&

LAT...LON 3674 11502 3685 11503 3685 11477 3672 11481
      3672 11495

$$

WOLCOTT
2 follow-up statements
379 
WGUS75 KVEF 212130
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
230 PM PDT TUE AUG 21 2012

NVC003-212215-
/O.CON.KVEF.FF.W.0139.000000T0000Z-120821T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
230 PM PDT TUE AUG 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 315 PM PDT FOR NORTH
CENTRAL CLARK COUNTY...

AT 222 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SHOWERS AND THUNDERSTORMS PRODUCING HEAVY RAIN. THESE 
STORMS WERE LOCATED NEAR THE INTERSECTION OF SR 168 AND US 93 NEAR 
COYOTE SPRINGS. THE STORMS WERE MOVING NORTHEAST AT 5 MPH.

LOCATIONS IMPACTED INCLUDE...
MAINLY RURAL AREAS OF EXTREME NORTHERN CLARK COUNTY...INCLUDING 
COYOTE SPRINGS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO CROSS A FLOODED
ROADWAY OR WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

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

&&

LAT...LON 3674 11502 3685 11503 3685 11477 3672 11481
      3672 11495

$$

WOLCOTT
190 
WGUS75 KVEF 212208
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
308 PM PDT TUE AUG 21 2012

NVC003-212216-
/O.EXP.KVEF.FF.W.0139.000000T0000Z-120821T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
308 PM PDT TUE AUG 21 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 315 PM PDT FOR NORTH
CENTRAL CLARK COUNTY...

THE STORMS THAT IMPACTED THE COYOTE SPRINGS AREA HAVE WEAKENED AN 
MOVED OUT OF THE AREA. MINIMAL IMPACTS WERE REPORTED IN THE AREA.

PLEASE REPORT SIGNIFICANT WEATHER OR FLOODING TO THE NATIONAL 
WEATHER SERVICE IN LAS VEGAS AT 1-800-240-4932.

LAT...LON 3674 11502 3685 11503 3685 11477 3672 11481
      3672 11495

$$

WOLCOTT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 11:39 AM PDTFlash Flood WatchVEFClark, Esmeralda, Lincoln, Nye36 hr
Aug 21, 1:09 PM PDTSevere Thunderstorm WarningVEFClark, Lincoln36 min
Aug 21, 1:42 PM PDTFlash Flood WarningVEFLincoln113 min
Aug 21, 2:47 PM PDTSpecial Weather StatementVEF43 min
Aug 21, 4:09 PM PDTSevere Thunderstorm WarningVEFClark51 min

Nearby

Flash Flood Warnings in Nevada, 2012Every flash flood 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.