Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 149, NWS Las Vegas, NV

August 22, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 22, 2012, 9:59 AM PDT for Clark County, Nevada. It was in force for 59 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, 9:59 AM PDT (16:59 UTC)
Expired
Aug 22, 2012, 10:58 AM PDT
In force
59 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 17:01 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, 10:45 AM PDTHEAVY RAIN 0.52 E Henderson, NVTRAINED SPOTTER REPORTED RECEIVING 0.50 INCHES OF RAIN IN 20 MINUTES.

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, 5.0 hours before the alert went out and 59 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°0°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.

597 
WGUS55 KVEF 221659
FFWVEF
NVC003-221900-
/O.NEW.KVEF.FF.W.0149.120822T1659Z-120822T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL NOON PDT.

* AT 952 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR HENDERSON. THE STORM   
PRODUCING VERY HEAVY RAIN WAS WAS MOVING NORTHEAST AT 10 TO 15 MPH.

* LOCATIONS IMPACTED INCLUDE...HENDERSON AND PORTIONS OF EAST LAS 
VEGAS.

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 11506 3610 11491 3599 11493 3600 11507

$$

KENNEDY
1 follow-up statement
288 
WGUS75 KVEF 221758
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1058 AM PDT WED AUG 22 2012

NVC003-221804-
/O.CAN.KVEF.FF.W.0149.000000T0000Z-120822T1900Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1058 AM PDT WED AUG 22 2012

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

THE FLASH FLOOD WARNING FOR HENDERSON AND EAST LAS VEGAS ISSUED AT 
959 AM THIS MORNING HAS BEEN CANCELLED AND  REPLACED BY A NEW FLASH 
FLOOD WARNING THAT INCLUDES THE ENTIRE LAS VEGAS VALLEY...THAT IS 
VALID UNTIL 145 PM PDT.

YOU MAY 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 11506 3610 11491 3599 11493 3600 11507

$$

KENNEDY

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, 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.