Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 58, NWS Las Vegas, NV

July 23, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 23, 2012, 1:11 PM PDT for Clark County, Nevada. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 23, 2012, 1:11 PM PDT (20:11 UTC)
Expired
Jul 23, 2012, 3:15 PM PDT
In force
2 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 80 km from the middle of the area, began a volume at 20:11 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, 8.2 hours before the alert went out and 49 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 2012-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 177 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 2012-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 5 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
177 J/kg
Mixed-layer CIN
-137 J/kg
Mixed-layer LCL
2252 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
5 m²/s²
0-3 km storm-relative helicity
-22 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.

062 
WGUS55 KVEF 232011
FFWVEF
NVC003-232215-
/O.NEW.KVEF.FF.W.0058.120723T2011Z-120723T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
111 PM PDT MON JUL 23 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 315 PM PDT.

* AT 107 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 9 MILES NORTH OF SANDY   
  VALLEY. THE STORM PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  SANDY VALLEY...THE SOUTHERN END OF THE PAHRUMP VALLEY...STATE
  ROUTE 160 AND THE OLD SPANISH TRAIL HIGHWAY

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 3600 11589 3610 11573 3594 11550 3578 11560

$$

JA
2 follow-up statements
063 
WGUS75 KVEF 232108 RRA
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
208 PM PDT MON JUL 23 2012

NVC003-232215-
/O.CON.KVEF.FF.W.0058.000000T0000Z-120723T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
208 PM PDT MON JUL 23 2012

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

HEAVY RAIN ENDED OVER THE AREA BETWEEN SANDY VALLEY AND PAHRUMP 
AROUDN 130 PM. HOWEVER...ESTIMATED RAINFALL AMOUNTS OVER 1 INCH 
OCCURRED IN THIS AREA AND RUNOFF WILL LIKELY PRODUCE FLOODING ACROSS 
SECONDARY ROADS FROM BETWEEN THE OLD SPANISH TRAIL HIGHWAY AND SANDY 
VALLEY.

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 3600 11589 3610 11573 3594 11550 3578 11560

$$

JA
557 
WGUS75 KVEF 232208
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
308 PM PDT MON JUL 23 2012

NVC003-232216-
/O.EXP.KVEF.FF.W.0058.000000T0000Z-120723T2215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
308 PM PDT MON JUL 23 2012

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

RUNOFF FROM HEAVY RAIN THAT OCCURRED EARLIER BETWEEN SANDY VALLEY 
AND PAHRUMP HAS LIKELY RECEDED AND THE FLASH FLOOD WARNING FOR THIS 
AREA WILL BE ALLOWED TO EXPIRE.

LAT...LON 3600 11589 3610 11573 3594 11550 3578 11560

$$

JA

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 12:46 AM PDTFlash Flood WarningVEFClark93 min
Jul 23, 6:02 AM PDTAreal Flood AdvisoryVEFClark58 min
Jul 23, 1:48 PM PDTAreal Flood AdvisoryVEFClark39 min
Jul 23, 3:52 PM PDTSevere Thunderstorm WarningVEFLincoln, Nye53 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.