Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 114, NWS Las Vegas, NV

August 14, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 14, 2012, 3:42 PM PDT for Clark County, Nevada. It was in force for 61 min. 3 reports 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
Aug 14, 2012, 3:42 PM PDT (22:42 UTC)
Expired
Aug 14, 2012, 4:43 PM PDT
In force
61 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), 41 km from the middle of the area, began a volume at 22:43 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
Aug 14, 3:50 PM PDTHEAVY RAIN 1.14 Ene Sloan, NVHEADWORKS CHANNEL DETENTION BASIN MEASURED A STORM TOTAL OF 1.10 INCHES OF RAIN...MOST OF WHICH FELL IN ROUGHLY AN HOUR.
Aug 14, 3:58 PM PDTFLASH FLOOD3 Sse Green Valley, NVSEVERAL INCHES OF FLOWING WATER ALONG WITH NUMEROUS ROCKS AND AREAS OF MUD WERE ON ROADS NEAR THE INTERSECTION OF ARROYO GRANDE AND HORIZON RIDGE IN HENDERSON.
Aug 14, 4:30 PM PDTHEAVY RAIN 0.52 E Green Valley, NV4 TO 6 INCHES OF STANDING WATER COVERED THE INTERSECTION OF WARM SPRINGS AND STEPHANIE.

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 12:00Z, 10.7 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-pSkew-T log-p diagram, Las Vegas, NV at 12:00Z on 2012-08-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2012-08-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2752 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
78 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.

494 
WGUS55 KVEF 142242
FFWVEF
NVC003-150045-
/O.NEW.KVEF.FF.W.0114.120814T2242Z-120815T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
342 PM PDT TUE AUG 14 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 545 PM PDT.

* AT 335 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM THUNDERSTORMS FALLING OVER THE SOUTH END OF  
  THE LAS VEGAS VALLEY. OVER FOUR TENTHS OF AN INCH HAVE FALLEN AT  
  AN AUTOMATED RAIN GAUGE IN ANTHEM AND SEVERAL INCHES OF WATER WERE 
  RUNNING DOWN EASTERN AVENUE NEAR HORIZON RIDGE. THIS WILL RESULT   
  IN WATER COLLECTING IN LOW LYING AREAS OF EASTERN AVENUE AND       
  ADJACENT CROSS STREETS AS WELL AS IN OTHER PORTIONS IN THE SOUTH   
  END OF THE LAS VEGAS VALLEY.

* LOCATIONS IMPACTED INCLUDE...
  HENDERSON...SOUTHERN HIGHLANDS...SEVEN HILLS...SILVERADO RANCH...
  GREEN VALLEY...MCCARRAN INTERNATIONAL AIRPORT...EAST LAS VEGAS AND
  SAM BOYD STADIUM.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. 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 3610 11526 3613 11495 3596 11499 3587 11511
      3592 11526

$$

STACHELSKI
2 follow-up statements
607 
WGUS75 KVEF 142307
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
407 PM PDT TUE AUG 14 2012

NVC003-150045-
/O.CON.KVEF.FF.W.0114.000000T0000Z-120815T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
407 PM PDT TUE AUG 14 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 343 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING VERY HEAVY RAIN. THIS STORM WAS 
LOCATED NEAR SEVEN HILLS...OR 7 MILES SOUTHWEST OF HENDERSON. THE 
THUNDERSTORM WITH EXCESSIVE RAIN WAS NEARLY STATIONARY. FLASH 
FLOODING WILL OCCUR IN LOW LYING AREAS OF THE SOUTH END OF THE LAS 
VEGAS VALLEY. IN ADDITION...RUNOFF WILL CAUSE ROCKS AND MUD TO WASH 
ONTO HILLY ROADS IN HENDERSON. ROCKS AND MUD WERE ALREADY REPORTED 
WASHED ONTO HORIZON RIDGE AND ARROYO GRANDE IN HENDERSON. AN 
AUTOMATED GAUGE IN ANTHEM HAS RECORDED 1.10 INCHES OF RAIN IN A 
LITTLE OVER AN HOUR. AREAS SUCH AS ANTHEM...MCDONALD RANCH...AND 
AREAS ALONG EASTERN AVENUE ESPECIALLY NEAR 215 ARE AMONG THOSE TO BE 
CAREFUL IN.

LOCATIONS IMPACTED INCLUDE...
HENDERSON...SILVERADO RANCH...GREEN VALLEY...MCCARRAN INTERNATIONAL
AIRPORT...EAST LAS VEGAS AND SAM BOYD STADIUM.

LAT...LON 3610 11526 3613 11495 3596 11499 3587 11511
      3592 11526

$$

STACHELSKI
447 
WGUS75 KVEF 142343
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
443 PM PDT TUE AUG 14 2012

NVC003-142350-
/O.CAN.KVEF.FF.W.0114.000000T0000Z-120815T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
443 PM PDT TUE AUG 14 2012

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

THE THUNDERSTORM THAT PRODUCE HEAVY RAIN OVER PARTS OF ANTHEM...GREEN 
VALLEY AND HENDERSON HAS WEAKENED. A FEW INCHES OF STANDING WATER 
MAY CONTINUE IN A FEW INTERSECTIONS. THE THREAT OF INTENSE RAINS AND 
THAT WOULD LEAD TO FAST FLOWING WATER HAS PASSED. THE FLASH FLOOD 
WARNING HAS BEEN CANCELLED. 

LAT...LON 3610 11526 3613 11495 3596 11499 3587 11511
      3592 11526

$$

PIERCE

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.