Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 142, NWS Las Vegas, NV

August 21, 2012Clark County, Lincoln County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 21, 2012, 6:10 PM PDT for Clark County, Lincoln County, Nevada. It was in force for 2 hr. 1 report 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 21, 2012, 6:10 PM PDT (01:10 UTC)
Expired
Aug 21, 2012, 8:15 PM PDT
In force
2 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

Counties Clark County, NV, Lincoln County, NV

The radar

The Las Vegas radar (KESX), 127 km from the middle of the area, began a volume at 01:11 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.

What was reported inside it

TimeReportWhereRemark
Aug 21, 6:15 PM PDTFLASH FLOOD14 Wnw Muddy River (Moa, NVTRAINED SPOTTERS REPORTED SMALL BUSHES AND ROCKS BEING PUSHED ACROSS US-93 SOUTH OF COYOTE SPRINGS. THE ROADWAY IS IMPASSIBLE AND WILL REQUIRE D.O.T. EQUIPMENT TO BE CLEARED.

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, 1.2 hours before the alert went out and 76 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 2012-08-22Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 00:00Z on 2012-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 53 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
3181 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
53 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

756 
WGUS55 KVEF 220110
FFWVEF
NVC003-017-220315-
/O.NEW.KVEF.FF.W.0142.120822T0110Z-120822T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 815 PM PDT.

* AT 606 PM PDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING
  FROM A THUNDERSTORM NEAR COYOTE SPRINGS...OR 20 MILES WEST OF
  MOAPA. THE STORM PRODUCING FLASH FLOODING WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  COYOTE SPRINGS AND SR 168 MILE MARKER 21.

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 3702 11487 3687 11489 3674 11473 3665 11488
      3665 11510 3698 11511

$$

WOLCOTT
3 follow-up statements
906 
WGUS75 KVEF 220119
FFSVEF

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

NVC003-017-220315-
/O.CON.KVEF.FF.W.0142.000000T0000Z-120822T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-LINCOLN NV-
619 PM PDT TUE AUG 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM PDT FOR SOUTH
CENTRAL LINCOLN AND NORTH CENTRAL CLARK COUNTIES...

AT 615 PM PDT...TRAINED WEATHER SPOTTERS REPORTED A THUNDERSTORM
PRODUCING FLASH FLOODING.  THIS STORM WAS LOCATED NEAR COYOTE
SPRINGS...OR 20 MILES NORTHWEST OF MOAPA. THE THUNDERSTORM WITH
EXCESSIVE RAIN WAS NEARLY STATIONARY.

THE SPOTTER REPORTED THAT WATER WAS FLOWING ACROSS U.S. HIGHWAY 93 
IN THE COYOTE SPRINGS AREA...AND HAS BECOMING IMPASSIBLE TO VEHICLES 
NEAR THE CLARK-LINCOLN COUNTY BORDER. PLEASE DO NOT ATTEMPT TO DRIVE 
THROUGH FLOODED ROADWAYS.

LOCATIONS IMPACTED INCLUDE...
MAINLY RURAL AREAS OF SOUTHERN LINCOLN AND NORTHERN CLARK COUNTIES 
COUNTIES...INCLUDING COYOTE SPRINGS.

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 3702 11487 3687 11489 3674 11473 3665 11488
      3665 11510 3698 11511

$$

WOLCOTT
084 
WGUS75 KVEF 220149
FFSVEF

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

NVC003-017-220315-
/O.CON.KVEF.FF.W.0142.000000T0000Z-120822T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-LINCOLN NV-
649 PM PDT TUE AUG 21 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM PDT FOR SOUTH
CENTRAL LINCOLN AND NORTH CENTRAL CLARK COUNTIES...

AT 630 PM PDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING 
OCCURRING ALONG U.S. HIGHWAY 93 SOUTH OF COYOTE SPRINGS NEAR MILE 
MARKER 79...JUST SOUTH OF THE CLARK-LINCOLN COUNTY LINE.

NUMEROUS STORMS PRODUCING VERY HEAVY RAINFALL HAVE MOVED ACROSS THE 
WARNED AREA THROUGHOUT THE DAY...OVERWHELMING AREA WASHES. WATER HAS 
NOW BEGUN TO FLOOD AREA ROADWAYS.

AT 640 PM PDT...TRAINED SPOTTERS REPORTED THAT NEVADA HIGHWAY PATROL 
HAD ARRIVED ON SCENE. WATER...ROCKS...AND DEBRIS WERE REPORTED 
FLOWING ACROSS THE HIGHWAY WHICH HAS NOW BEEN CLOSED. PLEASE DO NOT 
ATTEMPT TO DRIVE THROUGH FLOODED AREAS.

LOCATIONS IMPACTED INCLUDE...
MAINLY RURAL AREAS OF SOUTHERN LINCOLN AND NORTHERN CLARK 
COUNTIES...INCLUDING U.S. HIGHWAY 93 NEAR 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 3702 11487 3687 11489 3674 11473 3665 11488
      3665 11510 3698 11511

$$

WOLCOTT
743 
WGUS75 KVEF 220317
FFSVEF

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

NVC003-017-220325-
/O.EXP.KVEF.FF.W.0142.000000T0000Z-120822T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-LINCOLN NV-
817 PM PDT TUE AUG 21 2012

...THE FLASH FLOOD WARNING HAS EXPIRED FOR SOUTH CENTRAL LINCOLN AND
NORTH CENTRAL CLARK COUNTIES...

HEAVY RAIN OVER THE AREA HAS ENDED AND THE WARNING WAS ALLOWED TO 
EXPIRE. HOWEVER...NEW THUNDERSTORM CELLS WERE DEVELOPING ALONG 
HIGHWAY 93 NEAR THE LINCOLN AND CLARK COUNTY BORDER. MOTORISTS 
TRAVELING ALONG HIGHWAY 93 SHOULD REMAIN ALERT FOR ADDITIONAL HEAVY 
RAIN AND REDUCED VISIBILITIES THROUGH 10 PM THIS EVENING.

LAT...LON 3702 11487 3687 11489 3674 11473 3665 11488
      3665 11510 3698 11511

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 6:47 PM PDTFlash Flood WarningVEFLincoln118 min
Aug 22, 12:12 AM PDTFlash Flood WarningVEFClark2 hr
Aug 22, 2:35 AM PDTFlash Flood WarningVEFClark115 min
Aug 22, 8:22 AM PDTAreal Flood AdvisoryVEFClark9 hr
Aug 22, 9:19 AM PDTAreal Flood AdvisoryVEFClark, Lincoln, Nye3 hr
Aug 22, 9:20 AM PDTFlash Flood WarningVEFClark101 min
Aug 22, 9:34 AM PDTFlash Flood WarningVEFClark116 min
Aug 22, 9:59 AM PDTFlash Flood WarningVEFClark59 min
Aug 22, 10:05 AM PDTFlash Flood WarningVEFEsmeralda76 min
Aug 22, 10:53 AM PDTFlash Flood WarningVEFClark4 hr
Aug 22, 12:12 PM PDTFlash Flood WarningVEFClark4 hr
Aug 22, 12:33 PM PDTFlash Flood WarningVEFClark117 min
Aug 22, 2:40 PM PDTAreal Flood AdvisoryVEFClark6 hr
Aug 22, 3:43 PM PDTFlash Flood WarningVEFClark2 hr

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.