Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 54, NWS Las Vegas, NV

July 23, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 23, 2012, 12:46 AM PDT for Clark County, Nevada. It was in force for 93 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
Jul 23, 2012, 12:46 AM PDT (07:46 UTC)
Expired
Jul 23, 2012, 2:19 AM PDT
In force
93 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), 102 km from the middle of the area, began a volume at 07:47 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 00:00Z, 7.8 hours before the alert went out and 117 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 2012-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 257 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 00:00Z on 2012-07-23The 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
257 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
3301 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
-6 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.

540 
WGUS55 KVEF 230746
FFWVEF
NVC003-230945-
/O.NEW.KVEF.FF.W.0054.120723T0746Z-120723T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
1246 AM PDT MON JUL 23 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 245 AM PDT.

* AT 1239 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 10 MILES EAST OF OVERTON
  BEACH...OR 15 MILES EAST OF OVERTON. THE STORM PRODUCING VERY HEAVY
  RAIN WAS NEARLY STATIONARY. 

* LOCATIONS IMPACTED INCLUDE...OVERTON BEACH AND ECHO BAY.

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.

CAMPERS AND HIKERS SHOULD BE ALERT TO THE POSSIBILITY OF RAPIDLY
RISING WATER AND BE PREPARED TO MOVE QUICKLY TO HIGHER GROUND IF
FLASH FLOODING IS OBSERVED.

&&

LAT...LON 3651 11406 3625 11443 3640 11444 3660 11419

$$
KENNEDY
2 follow-up statements
013 
WGUS75 KVEF 230835
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
135 AM PDT MON JUL 23 2012

NVC003-230945-
/O.CON.KVEF.FF.W.0054.000000T0000Z-120723T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
135 AM PDT MON JUL 23 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 245 AM PDT FOR EAST
CENTRAL CLARK COUNTY...

AT 130 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE SHOWERS EAST OF OVERTON IN OVER THE WARNED AREA. WITH RADAR 
PRECIPITATION ESTIMATES BETWEEN TWO AND THREE INCHES ASSOCIATED WITH 
PRIOR THUNDERSTORMS...FLASH FLOODING IS LIKELY STILL OCCURRING IN 
AREA WASHES AND LOW LYING AREAS.

LOCATIONS IMPACTED INCLUDE...
MAINLY RURAL AREAS OF EASTERN CLARK COUNTY.

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.

CAMPERS AND HIKERS SHOULD BE ALERT TO THE POSSIBILITY OF RAPIDLY
RISING WATER AND BE PREPARED TO MOVE QUICKLY TO HIGHER GROUND IF
FLASH FLOODING IS OBSERVED.

&&

LAT...LON 3651 11406 3625 11443 3640 11444 3660 11419

$$

KENNEDY
613 
WGUS75 KVEF 230919
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
219 AM PDT MON JUL 23 2012

NVC003-230925-
/O.CAN.KVEF.FF.W.0054.000000T0000Z-120723T0945Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
219 AM PDT MON JUL 23 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR EAST CENTRAL CLARK
COUNTY...

ALTHOUGH SCATTERED SHOWERS CONTINUE TO DEVELOP EAST OF OVERTON AND 
OVERTON BEACH...PRECIPITATION IS LIGHTER AND ADDITIONAL HEAVY 
PRECIPITATION IS NOT EXPECTED. ANY FLOODING WHICH OCCURRED SHOULD 
RECEDE. 

LAT...LON 3651 11406 3625 11443 3640 11444 3660 11419

$$

KENNEDY

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 6:02 AM PDTAreal Flood AdvisoryVEFClark58 min
Jul 23, 1:11 PM PDTFlash Flood WarningVEFClark2 hr
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.