Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 158, NWS Las Vegas, NV

August 22, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 22, 2012, 12:33 PM PDT for Clark County, Nevada. It was in force for 117 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
Aug 22, 2012, 12:33 PM PDT (19:33 UTC)
Expired
Aug 22, 2012, 2:30 PM PDT
In force
117 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), 27 km from the middle of the area, began a volume at 19:37 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, 7.6 hours before the alert went out and 116 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 2012-08-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 296 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 2012-08-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 103 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
296 J/kg
Mixed-layer CIN
-130 J/kg
Mixed-layer LCL
1290 m above ground
0-6 km bulk shear
28 kt
0-1 km storm-relative helicity
103 m²/s²
0-3 km storm-relative helicity
176 m²/s²
Significant tornado parameter
0.1
Supercell composite
3.4

Open this sounding in Storm Lab

The text

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

039 
WGUS55 KVEF 221933
FFWVEF
NVC003-222130-
/O.NEW.KVEF.FF.W.0158.120822T1933Z-120822T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
1233 PM PDT WED AUG 22 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 230 PM PDT.

* AT 1224 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM THUNDERSTORMS ALONG A LINE EXTENDING FROM 9
  MILES WEST OF SEARCHLIGHT TO CAL NEV ARI...OR ALONG A LINE
  EXTENDING FROM 9 MILES WEST OF SEARCHLIGHT TO 14 MILES SOUTH OF   
  SEARCHLIGHT. THE STORMS PRODUCING VERY HEAVY RAIN WERE MOVING 
  NORTHEAST AROUND 20 MPH. 

* LOCATIONS IMPACTED INCLUDE...
  SEARCHLIGHT AND CAL NEV ARI.

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 3566 11501 3529 11465 3517 11483 3551 11518

$$

ASG
2 follow-up statements
670 
WGUS75 KVEF 222034
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
134 PM PDT WED AUG 22 2012

NVC003-222130-
/O.CON.KVEF.FF.W.0158.000000T0000Z-120822T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
134 PM PDT WED AUG 22 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

AT 129 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE VERY HEAVY RAIN BETWEEN SEARCHLIGHT AND CAL NEV ARI. THESE 
STORMS WERE MOVING NORTHEAST AT 20 MPH.

LOCATIONS IMPACTED INCLUDE...
SEARCHLIGHT AND CAL NEV ARI.

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 3566 11501 3529 11465 3517 11483 3551 11518

$$

ASG
404 
WGUS75 KVEF 222123 RRA
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
223 PM PDT WED AUG 22 2012

NVC003-222132-
/O.EXP.KVEF.FF.W.0158.000000T0000Z-120822T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
223 PM PDT WED AUG 22 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 230 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

THE THUNDERSTORM THAT PROMPTED THE WARNING HAS WEAKENED AND MOVED 
NORTHEAST. LIGHT TO MODERATE RAIN IS STILL EXPECTED OVER THE NEXT 
HOUR...BUT THE THREAT OF ADDITIONAL FLOODING HAS ENDED. 

LAT...LON 3566 11501 3529 11465 3517 11483 3551 11518

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 6:10 PM PDTFlash Flood WarningVEFClark, Lincoln2 hr
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, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.