Alert archive / Nevada / Flash Flood Warnings in 2011

Flash Flood Warning 43, NWS Las Vegas, NV

July 8, 2011Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 8, 2011, 1:08 PM PDT for Clark County, Nevada. It was in force for 112 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
Jul 8, 2011, 1:08 PM PDT (20:08 UTC)
Expired
Jul 8, 2011, 3:00 PM PDT
In force
112 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), 30 km from the middle of the area, began a volume at 20:11 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, 8.1 hours before the alert went out and 113 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 2011-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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 2011-07-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
44 J/kg
Mixed-layer CIN
-297 J/kg
Mixed-layer LCL
2374 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

571 
WGUS55 KVEF 082008
FFWVEF
NVC003-082200-
/O.NEW.KVEF.FF.W.0043.110708T2008Z-110708T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
108 PM PDT FRI JUL 8 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 300 PM PDT.

* AT 100 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 8 MILES WEST OF SEARCHLIGHT...
  MOVING SOUTHEAST AT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...CAL NEV ARI AND SEARCHLIGHT...NIPTON
  ROAD AND HIGHWAY 95 FROM SEARCHLIGHT SOUTH TO THE BORDER.

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3555 11513 3548 11487 3526 11484 3543 11515

$$

SC
2 follow-up statements
808 
WGUS75 KVEF 082047 RRA
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
147 PM PDT FRI JUL 8 2011

NVC003-082200-
/O.CON.KVEF.FF.W.0043.000000T0000Z-110708T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
147 PM PDT FRI JUL 8 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

AT 145 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE A THUNDERSTORM PRODUCING VERY HEAVY RAIN.  THIS STORM WAS
LOCATED NEAR CAL NEV ARI...OR 9 MILES SOUTH OF SEARCHLIGHT...MOVING 
SOUTHEAST AT 5 MPH. A RAIN GAGE NEAR SEARCHLIGHT RECEIVED 0.98 
INCHES OF RAIN IN THIRTY MINUTES. ADDITIONAL THUNDERSTORMS HAVE 
DEVELOPED ON THE EAST SIDE OF HIGHWAY 95...ALSO PRODUCING VERY HEAVY 
RAIN. 

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

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3555 11513 3548 11487 3526 11484 3543 11515

$$

SC
690 
WGUS75 KVEF 082155
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
255 PM PDT FRI JUL 8 2011

NVC003-082202-
/O.EXP.KVEF.FF.W.0043.000000T0000Z-110708T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
255 PM PDT FRI JUL 8 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 300 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

THE FLASH FLOOD WARNING FOR SOUTH CENTRAL CLARK COUNTY WILL BE 
ALLOWED TO EXPIRE AT 300 PM. THE HEAVY RAIN HAS MOVED TO THE SOUTH 
AND THE IMMEDIATE THREAT OF FLASH FLOODING HAS ENDED. LINGERING 
MINOR FLOODING MAY PERSIST AS RUNOFF CONTINUES TO DIMINISH... 
PARTICULARLY ALONG NIPTON ROAD. 

LAT...LON 3555 11513 3548 11487 3526 11484 3543 11515

$$

SC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 6:43 PM PDTAreal Flood AdvisoryVEFClark107 min
Jul 7, 7:33 PM PDTAreal Flood AdvisoryVEFClark48 min
Jul 8, 12:21 PM PDTFlash Flood WarningVEFClark70 min
Jul 8, 12:29 PM PDTAreal Flood AdvisoryVEFClark46 min
Jul 8, 2:33 PM PDTSevere Thunderstorm WarningVEFClark29 min
Jul 8, 2:45 PM PDTAreal Flood AdvisoryVEFClark57 min

Nearby

Flash Flood Warnings in Nevada, 2011Every flash flood warning in 2011

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.