Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 221, NWS Las Vegas, NV

October 11, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Oct 11, 2012, 8:21 PM PDT for Clark County, Nevada. It was in force for 114 min. 8 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
Oct 11, 2012, 8:21 PM PDT (03:21 UTC)
Expired
Oct 11, 2012, 10:15 PM PDT
In force
114 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), 60 km from the middle of the area, began a volume at 03:21 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
Oct 11, 8:45 PM PDTFLASH FLOOD4 W Las Vegas Strip, NV1 FOOT OF FLOWING WATER AT THE INTERSECTION OF SPRING MOUNTAIN RD AND RAINBOW.
Oct 11, 8:50 PM PDTFLASH FLOOD2 Ese Las Vegas, NVAT LEAST 4 SWIFTWATER RESCUES WERE REPORTED IN THE LAS VEGAS VALLEY - ONE WAS AT EASTERN AND STEWART AND ANOTHER WAS AT CALICO NEAR JONES. THE EVENT TIME IS AN ESTIMATE.
Oct 11, 9:00 PM PDTFLASH FLOOD2 Nnw Las Vegas, NVLAS VEGAS AREA BROADCAST MEDIA REPORTED FLOODWATERS ENTERED ONE HOME NEAR MARTIN LUTHER KING AND CAREY.
Oct 11, 9:00 PM PDTFLASH FLOOD4 Ene Las Vegas, NV8 INCHES OF WATER FLOWING DOWN THE CENTER OF OWENS AVE.
Oct 11, 9:12 PM PDTHEAVY RAIN 1.815 N Las Vegas, NVA STORM TOTAL OF 1.81 INCHES WAS MEASURED AT AN AUTOMATED RAIN GAUGE NEAR CAMINO EL NORTE AND CRAIG ROAD IN NORTH LAS VEGAS SINCE 3 PM ON 10/10/12. 0.94 INCH FELL IN 30 MINUTES FROM 840 PM TO 910 PM ON 10/11/12.
Oct 11, 9:15 PM PDTFLASH FLOOD1 W Las Vegas, NVRAMP FROM I 15 NORTH TO US 95 NORTH IS CLOSED DUE TO 6 TO 12 INCHES OF WATER ON THE ROADWAY.
Oct 11, 9:25 PM PDTFLASH FLOOD6 Ne Las Vegas, NVOVER 6 INCHES OF WATER FLOWING DOWN CRAIG ROAD
Oct 11, 9:39 PM PDTFLASH FLOOD3 E Las Vegas, NV6 INCHES OF FLOWING WATER WITH ROCKS AND DEBRIS AT GILMORE AND EL CAPITAN.

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, 3.4 hours before the alert went out and 37 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 2012-10-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 305 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 00:00Z on 2012-10-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 56 square meters per square second.1939587897Sfc1 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
305 J/kg
Mixed-layer CIN
-43 J/kg
Mixed-layer LCL
1141 m above ground
0-6 km bulk shear
64 kt
0-1 km storm-relative helicity
56 m²/s²
0-3 km storm-relative helicity
58 m²/s²
Significant tornado parameter
0.1
Supercell composite
1.3

Open this sounding in Storm Lab

The text

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

056 
WGUS55 KVEF 120321
FFWVEF
NVC003-120515-
/O.NEW.KVEF.FF.W.0221.121012T0321Z-121012T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
821 PM PDT THU OCT 11 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 1015 PM PDT.

* AT 815 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM AN AREA OF THUNDERSTORMS MOVING NORTH AT 10   
  TO 20 MPH ACROSS THE LAS VEGAS VALLEY. VERY HEAVY RAIN WAS         
  REPORTED IN MANY NEIGHBORHOODS WITH THIS AREA OF THUNDERSTORMS IN  
  THE LAS VEGAS VALLEY. 

* LOCATIONS IMPACTED INCLUDE...
  SUMMERLIN...NORTH LAS VEGAS...NELLIS AFB...NORTH LAS VEGAS
  AIRPORT...LONE MOUNTAIN...CENTENNIAL HILLS...ALIANTE AND NELLIS AIR
  FORCE BASE AS WELL AS THE NORTHERN END OF KYLE CANYON ROAD TO MT   
  CHARLESTON.

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 3638 11552 3630 11496 3594 11496 3591 11501
      3607 11507 3619 11551

$$

STACHELSKI
3 follow-up statements
415 
WGUS75 KVEF 120426
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
926 PM PDT THU OCT 11 2012

NVC003-120515-
/O.CON.KVEF.FF.W.0221.000000T0000Z-121012T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
926 PM PDT THU OCT 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 918 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A THUNDERSTORM PRODUCING VERY HEAVY RAIN.  THIS STORM WAS 
LOCATED NEAR NELLIS AFB...MOVING NORTH AT 15 MPH. RAINFALL RATES 
HAVE BEEN INTENSE WITH THIS STORM. NUMEROUS RAINFALL GAGES HAVE 
RECEIVED 0.75 INCHES OF RAINFALL IN FIFTEEN MINUTES WITH STORM.

LOCATIONS IMPACTED INCLUDE...NELLIS AFB AND ALIANTE

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 3638 11552 3630 11496 3594 11496 3591 11501
      3607 11507 3619 11551

$$

CZYZYK
519 
WGUS75 KVEF 120444
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
944 PM PDT THU OCT 11 2012

NVC003-120515-
/O.CON.KVEF.FF.W.0221.000000T0000Z-121012T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
944 PM PDT THU OCT 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 936 PM PDT...FLASH FLOODING CONTINUES ACROSS THE CENTRAL AND 
NORTHERN PORTIONS OF THE LAS VEGAS VALLEY...WITH MULTIPLE SWIFT 
WATER RESCUES TAKING PLACE...INCLUDING AT EASTERN AND STEWART AND 
CALICO NEAR JONES. WASHES IN THE AREA ARE RUNNING RAPIDLY. THE HEAVY 
RAIN HAS ENDED...BUT ADDITIONAL RAIN IS POSSIBLE LATER THIS EVENING 
AND OVERNIGHT.

LOCATIONS IMPACTED INCLUDE...
DOWNTOWN LAS VEGAS...SUMMERLIN...NORTH LAS VEGAS...NELLIS AFB...NORTH
LAS VEGAS AIRPORT...NELLIS AIR FORCE BASE...LONE MOUNTAIN...ALIANTE
AND CENTENNIAL HILLS.

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 3638 11552 3630 11496 3594 11496 3591 11501
      3607 11507 3619 11551

$$

CZYZYK
399 
WGUS75 KVEF 120520
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1020 PM PDT THU OCT 11 2012

NVC003-120526-
/O.EXP.KVEF.FF.W.0221.000000T0000Z-121012T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1020 PM PDT THU OCT 11 2012

...THE FLASH FLOOD WARNING HAS EXPIRED FOR CENTRAL CLARK COUNTY...

THE FLASH FLOOD WARNING FOR CENTRAL CLARK COUNTY HAS BEEN REPLACED 
BY A NEW FLASH FLOOD WARNING. THE NEW AREA HAS BEEN REDUCED IN SIZE 
AND INCLUDES NORTH LAS VEGAS...NELLIS AFB...DOWNTOWN LAS VEGAS AND 
ALIANTE.

LAT...LON 3638 11552 3630 11496 3594 11496 3591 11501
      3607 11507 3619 11551

$$

CZYZYK

The office that day

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

IssuedProductOfficeCountiesLasted
Oct 11, 5:25 PM PDTSevere Thunderstorm WarningVEFClark, Nye35 min
Oct 11, 5:52 PM PDTSevere Thunderstorm WarningVEFNye53 min
Oct 11, 6:45 PM PDTFlash Flood WarningVEFClark2 hr
Oct 11, 7:56 PM PDTFlash Flood WarningVEFClark80 min
Oct 11, 8:12 PM PDTSevere Thunderstorm WarningVEFClark48 min
Oct 11, 8:57 PM PDTSevere Thunderstorm WarningVEFClark48 min
Oct 11, 9:07 PM PDTFlash Flood WarningVEFClark113 min
Oct 11, 9:40 PM PDTSevere Thunderstorm WarningVEFClark27 min
Oct 11, 10:15 PM PDTFlash Flood WarningVEFClark2 hr
Oct 11, 10:42 PM PDTFlash Flood WarningVEFClark94 min
Oct 12, 12:03 AM PDTFlash Flood WarningVEFNye87 min
Oct 12, 12:28 AM PDTSevere Thunderstorm WarningVEFLincoln32 min
Oct 12, 1:43 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.