Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 224, NWS Las Vegas, NV

October 11, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Oct 11, 2012, 10:15 PM PDT for Clark County, Nevada. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Oct 11, 2012, 10:15 PM PDT (05:15 UTC)
Expired
Oct 12, 2012, 12:15 AM PDT
In force
2 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 62 km from the middle of the area, began a volume at 05:18 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 00:00Z, 5.3 hours before the alert went out and 42 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.

429 
WGUS55 KVEF 120515
FFWVEF
NVC003-120715-
/O.NEW.KVEF.FF.W.0224.121012T0515Z-121012T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
1015 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 1215 AM PDT.

* AT 1006 PM PDT...FLASH FLOODING WAS CONTINUING ACROSS PORTIONS OF  
  THE CENTRAL AND NORTHERN LAS VEGAS VALLEY...WHERE SEVERAL 
  SWIFT WATER RESCUES HAVE ALREADY TAKEN PLACE. NATIONAL WEATHER 
  SERVICE DOPPLER RADAR INDICATED ANOTHER AREA OF SHOWERS AND 
  THUNDERSTORMS MOVING INTO THE SOUTHERN PORTIONS OF THE LAS VEGAS 
  VALLEY. THESE SHOWERS AND THUNDERSTORMS WERE MOVING TO THE NORTH
  AT 25 MPH AND WILL LIKELY AGGRAVATE ONGOING FLOODING.
 
* LOCATIONS IMPACTED INCLUDE...
  DOWNTOWN LAS VEGAS...NORTH LAS VEGAS...NELLIS AFB...NORTH LAS VEGAS
  AIRPORT...NELLIS AIR FORCE BASE 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 3633 11520 3630 11496 3623 11499 3607 11507
      3611 11523

$$

CZYZYK
2 follow-up statements
921 
WGUS75 KVEF 120609
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1109 PM PDT THU OCT 11 2012

NVC003-120715-
/O.CON.KVEF.FF.W.0224.000000T0000Z-121012T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1109 PM PDT THU OCT 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1215 AM PDT FOR
CENTRAL CLARK COUNTY...

AT 1100 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
THUNDERSTORMS CAPABLE OF PRODUCING FLASH FLOODING.  ONE STORM WAS 
LOCATED NEAR ALIANTE...OR NEAR NORTH LAS VEGAS...AND A SECOND NEAR 
NELLIS AIR FORCE BASE...MOVING NORTH AT 35 MPH.

LOCATIONS IMPACTED INCLUDE...ALIANTE...NORTH LAS VEGAS...NELLIS 
AFB...DOWNTOWN 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 3633 11520 3630 11496 3623 11499 3607 11507
      3611 11523

$$

CZYZYK
353 
WGUS75 KVEF 120714
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1214 AM PDT FRI OCT 12 2012

NVC003-120716-
/O.EXP.KVEF.FF.W.0224.000000T0000Z-121012T0715Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
1214 AM PDT FRI OCT 12 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1215 AM PDT FOR CENTRAL
CLARK COUNTY...

ALTHOUGH SHOWERS AND THUNDERSTORMS ARE STILL POSSIBLE THE REMAINDER 
OF THE NIGHT ACROSS THE LAS VEGAS VALLEY...HEAVY RAINFALL IS NOT 
BEING EXPERIENCED AT THIS TIME. THUS WILL ALLOW THE FLASH FLOOD 
WARNING TO EXPIRE AS OF 1215 AM PDT.

HOWEVER MOTORISTS SHOULD CONTINUE TO USE EXTRA CAUTION TONIGHT AS 
PONDING
OF WATER IN LOW LYING AREAS IS LIKELY TO STILL BE ENCOUNTERED...AND 
AREAS SUSCEPTIBLE TO FLOODING DURING PERIODS OF HEAVY RAIN ARE 
LIKELY STILL SEEING IMPACTS FROM THE EARLIER RAINFALL.

LAT...LON 3633 11520 3630 11496 3623 11499 3607 11507
      3611 11523

$$

KENNEDY

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, 8:21 PM PDTFlash Flood WarningVEFClark114 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, 10:42 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.