Alert archive / Nevada / Flash Flood Warnings in 2011

Flash Flood Warning 38, NWS Las Vegas, NV

July 7, 2011Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 7, 2011, 4:52 PM PDT for Clark County, Nevada. It was in force for 113 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 7, 2011, 4:52 PM PDT (23:52 UTC)
Expired
Jul 7, 2011, 6:45 PM PDT
In force
113 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), 20 km from the middle of the area, began a volume at 23:54 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, 11.9 hours before the alert went out and 109 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 2011-07-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 34 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 2011-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
34 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
2113 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
114 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.

109 
WGUS55 KVEF 072352
FFWVEF
NVC003-080145-
/O.NEW.KVEF.FF.W.0038.110707T2352Z-110708T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
452 PM PDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 645 PM PDT.

* AT 450 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
VERY HEAVY RAIN FROM A THUNDERSTORM 7 MILES NORTH OF SEARCHLIGHT. 
THE STORM PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY. RADAR 
ESTIMATES TWO TO THREE INCHES OF RAIN HAS FALLEN SINCE 4 PM IN THE AREA.

* LOCATIONS IMPACTED INCLUDE...SEARCHLIGHT...AND HIGHWAY 95 FROM MILE 
MARKER 16 TO 34.

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 3563 11499 3565 11486 3542 11483 3539 11492
      3543 11502

$$

JGG
2 follow-up statements
900 
WGUS75 KVEF 080023
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
523 PM PDT THU JUL 7 2011

NVC003-080145-
/O.CON.KVEF.FF.W.0038.000000T0000Z-110708T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
523 PM PDT THU JUL 7 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

AT 522 PM PDT...RADAR CONTINUED TO INDICATE THUNDERSTORMS PRODUCING HEAVY
RAIN MOVING ACROSS THE SAME AREA JUST NORTH OF SEARCHLIGHT ALONG HIGHWAY 95.
ANOTHER AREA OF HEAVY RAIN HAS DEVELOPED JUST WEST OF SEARCHLIGHT ACROSS
HIGHWAY 164.  RADAR ESTIMATES TWO TO THREE INCHES OF RAINFALL HAS FALLEN
SINCE ABOUT 330 PM IN THAT AREA. 

LOCATIONS IMPACTED INCLUDE...SEARCHLIGHT....HIGHWAY 95 BETWEEN MILE MARKER 
16 AND 34 AND HIGHWAY 164 FROM MILE MARKER 13 TO SEARCHLIGHT. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS SITUATION. 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 3563 11499 3565 11486 3542 11483 3539 11492
      3543 11502

$$

JGG
779 
WGUS75 KVEF 080144
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
644 PM PDT THU JUL 7 2011

NVC003-080154-
/O.EXP.KVEF.FF.W.0038.000000T0000Z-110708T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
644 PM PDT THU JUL 7 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 645 PM PDT FOR SOUTH
CENTRAL CLARK COUNTY...

THE WARNING HAS BEEN REPLACED BY A FLOOD ADVISORY EFFECTIVE UNTIL
830 PM.

LAT...LON 3563 11499 3565 11486 3542 11483 3539 11492
      3543 11502

$$

JGG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 5:48 PM PDTAreal Flood AdvisoryVEFClark, Nye71 min
Jul 7, 1:01 PM PDTAreal Flood AdvisoryVEFClark43 min
Jul 7, 1:16 PM PDTFlash Flood WarningVEFClark119 min
Jul 7, 2:54 PM PDTSevere Thunderstorm WarningVEFClark51 min
Jul 7, 3:01 PM PDTSevere Thunderstorm WarningVEFClark33 min
Jul 7, 3:18 PM PDTSevere Thunderstorm WarningVEFClark42 min
Jul 7, 3:32 PM PDTSevere Thunderstorm WarningVEFClark43 min
Jul 7, 3:35 PM PDTFlash Flood WarningVEFClark114 min
Jul 7, 4:26 PM PDTAreal Flood AdvisoryVEFClark74 min
Jul 7, 4:29 PM PDTSevere Thunderstorm WarningVEFClark46 min
Jul 7, 4:37 PM PDTFlash Flood WarningVEFClark53 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.