Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 145, NWS Las Vegas, NV

August 22, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 22, 2012, 2:35 AM PDT for Clark County, Nevada. It was in force for 115 min. 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 22, 2012, 2:35 AM PDT (09:35 UTC)
Expired
Aug 22, 2012, 4:30 AM PDT
In force
115 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), 133 km from the middle of the area, began a volume at 09:36 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 22, 3:36 AM PDTHEAVY RAIN 1.51 Wsw Bunkerville, NVSTORM TOTAL PRECIPITATION SO FAR HAS BEEN 1.50 INCHES IN THE PAST 2-3 HOURS. POWER IS OUT ALSO.

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, 9.6 hours before the alert went out and 124 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°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.

229 
WGUS55 KVEF 220935
FFWVEF
NVC003-221130-
/O.NEW.KVEF.FF.W.0145.120822T0935Z-120822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 430 AM PDT.

* AT 232 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM THUNDERSTORMS OVER BUNKERVILLE AND MESQUITE.
  THESE STORMS WERE MOVING TO THE NORTHEAST AT 20 MPH BUT WERE
  REGENERATING TO THE SOUTHWEST AND MOVING REPEATEDLY OVER THE
  SAME AREA. RAINFALL AMOUNTS UP TO THREE-QUARTERS OF AN INCH
  HAVE FALLEN SINCE 145 AM AND AN ADDITIONAL HALF INCH TO ONE
  INCH IS LIKELY BEFORE THE RAIN ENDS.

* LOCATIONS IMPACTED INCLUDE...
  MESQUITE AND BUNKERVILLE.

THIS INCLUDES INTERSTATE 15 BETWEEN MILE MARKERS 105 AND 120.

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 3683 11433 3684 11406 3669 11406 3669 11441

$$

JA
2 follow-up statements
047 
WGUS75 KVEF 221042
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
342 AM PDT WED AUG 22 2012

NVC003-221130-
/O.CON.KVEF.FF.W.0145.000000T0000Z-120822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
342 AM PDT WED AUG 22 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 AM PDT FOR
NORTHEASTERN CLARK COUNTY...

AT 328 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS SLOWLY MOVING NORTHEAST ACROSS THE EXTREME 
NORTHEAST CORNER OF CLARK COUNTY...OR ACROSS THE 
BUNKERVILLE/MESQUITE AREAS.

AS OF 335 AM PDT...A TRAINED STORM SPOTTER REPORTED THAT 1.50 INCHES 
OF RAIN HAD FALLEN SO FAR IN THE BUNKERVILLE AREA. REPORTS ARE ALSO 
SHOWING THAT WATER IS FLOWING IN THE NORMALLY DRY WASHES AND 
DRAINAGE CHANNELS. 

LOCATIONS IMPACTED INCLUDE...

THIS INCLUDES INTERSTATE 15 BETWEEN MILE MARKERS 105 AND 120.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS EVEN HARDER TO SEE WATER 
COVERING THE ROADWAY OR IN LOW WATER CROSSINGS.

&&

LAT...LON 3683 11433 3684 11406 3669 11406 3669 11441

$$

JENSEN
568 
WGUS75 KVEF 221126
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
426 AM PDT WED AUG 22 2012

NVC003-221132-
/O.EXP.KVEF.FF.W.0145.000000T0000Z-120822T1130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
426 AM PDT WED AUG 22 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 AM PDT FOR NORTHEASTERN
CLARK COUNTY...

THUNDERSTORMS HAVE MOVED OUT OF THE AREA AND HEAVY RAINFALL IS NO 
LONGER BEING REPORTED. THUS WILL ALLOW THE FLASH FLOOD WARNING TO 
EXPIRE AS OF 430 AM PDT.

HOWEVER ADDITIONAL SHOWERS AND THUNDERSTORMS ARE FORMING AROUND 
CLARK COUNTY AND MAY MOVED ACROSS THE BUNKERVILLE/MESQUITE AREAS 
ONCE AGAIN. ANY ADDITIONAL RAINFALL WILL ADD TO THE HEAVY RAINFALL 
OF EARLIER AND CONTINUE TO CREATE POTENTIAL PROBLEMS.

WATER WILL LIKELY BE FLOWING THROUGH THE NORMALLY DRY WASHES AND 
ACROSS LOW WATER CROSSING THROUGH THE MORNING. MOTORIST ARE URGED TO 
CONTINUE USING CAUTION...ESPECIALLY UNTIL SUNRISE AS WATER IS VERY 
HARD TO SEE AT NIGHT.

LAT...LON 3683 11433 3684 11406 3669 11406 3669 11441

$$

JENSEN

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, 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.