Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 34, NWS Las Vegas, NV

July 14, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 14, 2012, 8:56 PM PDT for Clark County, Nevada. It was in force for 109 min. 4 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
Jul 14, 2012, 8:56 PM PDT (03:56 UTC)
Expired
Jul 14, 2012, 10:45 PM PDT
In force
109 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), 77 km from the middle of the area, began a volume at 03:59 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
Jul 14, 9:30 PM PDTFLASH FLOOD1 Nne Centennial Hills, NVSWIFT WATER RESCUE WAS REPORTED ON WEST DEER SPRINGS WAY BETWEEN 7601 AND 7809.
Jul 14, 10:00 PM PDTFLASH FLOOD3 Nne Summerlin, NVA SPOTTER REPORTED FLASH FLOODING ON EL CAPITAN BETWEEN GILMORE AND ALEXANDER THAT COVERED BOTH LANES. THE WATER ON GILMORE IS APPROXIMATE 4 INCHES DEEP AND THE WATER ON ALEXANDER IS APPROXIMATELY 8 INCHES DEEP. THREE AND HALF TO 5 INCH DIAMETER STONES COVERED
Jul 14, 10:00 PM PDTFLASH FLOOD4 W North Las Vegas, NV3 TO 4 INCHES OF WATER COLLECTED ON DECATUR BOULEVARD NORTH ALONG WITH A SMALL AMOUNT OF MUD AND SMALL ROCKS JUST SOUTH OF THE INTERSECTION WITH 215 NORTH. AROUND 4 INCHES OF WATER ON DECATUR BOULEVARD NEAR THE INTESECTION OF WASHINGTON ROAD WAS STILL ON THE G
Jul 14, 10:05 PM PDTFLASH FLOOD2 Nne Centennial Hills, NV3 FEET OF WATER ON BUFFALO DRIVE NEAR GRAND TEATON.

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 00:00Z, 3.9 hours before the alert went out and 24 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 2012-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 48 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 2012-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 square meters per square second.193958Sfc1 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
48 J/kg
Mixed-layer CIN
-202 J/kg
Mixed-layer LCL
2462 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
-43 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.

496 
WGUS55 KVEF 150356
FFWVEF
NVC003-150545-
/O.NEW.KVEF.FF.W.0034.120715T0356Z-120715T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
856 PM PDT SAT JUL 14 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  THE FAR NORTHWEST LAS VEGAS VALLEY IN CENTRAL CLARK COUNTY IN      
  SOUTHERN NEVADA...

* UNTIL 1045 PM PDT.

* AT 846 PM PDT...SPOTTERS AND RAIN GAGE AMOUNTS INDICATE VERY HEAVY 
  RAIN IS FALLING FROM A THUNDERSTORM OVER THE FAR NORTHWEST VALLEY  
  IN THE CENTENNIAL HILLS AREA. 

* LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF CENTRAL CLARK COUNTY.

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 3637 11537 3638 11516 3625 11517 3623 11535

$$

JS
2 follow-up statements
280 
WGUS75 KVEF 150509
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1009 PM PDT SAT JUL 14 2012

NVC003-150545-
/O.CON.KVEF.FF.W.0034.000000T0000Z-120715T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1009 PM PDT SAT JUL 14 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 PM PDT FOR THE 
CENTENNIAL AREA OF CENTRAL CLARK COUNTY...

AT 955 PM PDT...THUNDERSTORMS HAVE DISSIPATED OVER THE NORTHWEST 
VALLEY BUT RUNOFF FROM THE EARLIER STORMS CONTINUES TO CREATE 
FLOODING ON AREA ROADWAYS AND HIGH WATER IN WASHES. MORE THAN AN 
INCH OF RAIN WAS REPORTED IN SOME LOCATIONS IN A 30 MINUTE TIME 
PERIOD. THE RANCHO DETENTION BASIN NEAR HIGHWAY 95 AND 215 REPORTED 
A WATER LEVEL OF GREATER THAN 7 FEET. 

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

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 3637 11537 3638 11516 3625 11517 3623 11535

$$

JS
739 
WGUS75 KVEF 150541
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1041 PM PDT SAT JUL 14 2012

NVC003-150548-
/O.EXP.KVEF.FF.W.0034.000000T0000Z-120715T0545Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1041 PM PDT SAT JUL 14 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1045 PM PDT FOR THE 
NORTHWEST VALLEY IN CENTRAL CLARK COUNTY...

THUNDERSTORMS HAVE DISSIPATED BUT WATER IS STILL BEING REPORTED ON 
ROADWAYS IN THE NORTHWEST VALLEY.FLASH FLOODING IS NO LONGER 
OCCURRING SO THE WARNING WILL BE ALLOWED TO EXPIRE ON TIME. 
MOTORISTS OUT AND ABOUT THIS EVENING SHOULD BE AWARE OF STANDING 
WATER ON AREA ROADS.

LAT...LON 3637 11537 3638 11516 3625 11517 3623 11535

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 6:02 PM PDTAreal Flood AdvisoryVEFClark116 min
Jul 14, 8:41 PM PDTAreal Flood AdvisoryVEFClark16 min
Jul 15, 10:14 AM PDTFlash Flood WatchVEFClark, Lincoln, Nye11 hr
Jul 15, 10:30 AM PDTFlash Flood WarningVEFLincoln4 hr
Jul 15, 1:12 PM PDTFlash Flood WarningVEFClark2 hr
Jul 15, 1:24 PM PDTFlash Flood WarningVEFNye4 hr
Jul 15, 1:58 PM PDTFlash Flood WarningVEFLincoln82 min
Jul 15, 2:16 PM PDTSevere Thunderstorm WarningVEFClark44 min
Jul 15, 2:41 PM PDTAreal Flood AdvisoryVEFClark3 hr
Jul 15, 3:01 PM PDTFlash Flood WarningVEFLincoln6 hr
Jul 15, 4:40 PM PDTFlash Flood WarningVEFClark65 min
Jul 15, 4:58 PM PDTFlash Flood WarningVEFClark92 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.