Alert archive / Nevada / Flash Flood Warnings in 2011

Flash Flood Warning 94, NWS Las Vegas, NV

September 14, 2011Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Sep 14, 2011, 1:52 PM PDT for Clark County, Nevada. It was in force for 92 min. 2 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
Sep 14, 2011, 1:52 PM PDT (20:52 UTC)
Expired
Sep 14, 2011, 3:24 PM PDT
In force
92 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), 62 km from the middle of the area, began a volume at 20:54 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.

What was reported inside it

TimeReportWhereRemark
Sep 14, 2:00 PM PDTHEAVY RAIN 1.223 W Spring Valley, NV1.22 INCHES OF RAIN BETWEEN 1330-1400 PM
Sep 14, 2:26 PM PDTFLASH FLOOD3 Wsw Spring Valley, NVSWIFT WATER RESUES AT THE JUNCTION OF FLAMINGO RD AND I-215. WATER UP TO CAR WINDOWS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 8.9 hours before the alert went out and 334 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, Flgstf/Belemont, AZ at 12:00Z on 2011-09-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 224 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2011-09-14The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.19395878Sfc1 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
224 J/kg
Mixed-layer CIN
-8 J/kg
Mixed-layer LCL
729 m above ground
0-6 km bulk shear
38 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
64 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

808 
WGUS55 KVEF 142052
FFWVEF
NVC003-142245-
/O.NEW.KVEF.FF.W.0094.110914T2052Z-110914T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
152 PM PDT WED SEP 14 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...
  INCLUDING PORTIONS OF THE WESTERN LAS VEGAS VALLEY

* UNTIL 345 PM PDT.

* AT 149 PM PDT...RAIN GAUGES NEAR 215 AND FLAMINGO INDICATED THAT 
HALF OF AN INCH OF RAIN HAS FALLEN SINCE 130 PM FROM VERY SLOW 
MOVING THUNDERSTORMS OVER THE AREA. ADDITIONAL HEAVY RAINFALL IS 
POSSIBLE.

* LOCATIONS IMPACTED INCLUDE...
  SUMMERLIN SOUTH AND SUMMERLIN WEST...AND THE 215 CORRIDOR IN 
  THE SOUTHWESTERN VALLEY.

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 3620 11541 3615 11525 3605 11524 3606 11533

$$

JGG
3 follow-up statements
879 
WGUS75 KVEF 142118
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
218 PM PDT WED SEP 14 2011

NVC003-142245-
/O.CON.KVEF.FF.W.0094.000000T0000Z-110914T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
218 PM PDT WED SEP 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 215 PM PDT...RAIN GAUGES NEAR THE 215 BELTWAY AND FLAMINGO 
REPORTED NEARLY ONE AND ONE QUARTER OF AN INCH OF RAIN HAS FALLEN 
SINCE 130 PM.  RADAR INDICATES THE HEAVIEST RAIN IS ENDING BUT 
MODERATE RAINFALL IS EXPECTED TO CONTINUE THROUGH 300 PM.

LOCATIONS IMPACTED INCLUDE...
SUMMERLIN SOUTH AND SUMMERLIN WEST...AND AREAS NEAR THE 215 BELTWAY  
IN THE SOUTHWESTERN VALLEY.

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 3620 11541 3615 11525 3605 11524 3606 11533

$$

JGG
475 
WGUS75 KVEF 142131
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
231 PM PDT WED SEP 14 2011

NVC003-142245-
/O.CON.KVEF.FF.W.0094.000000T0000Z-110914T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
231 PM PDT WED SEP 14 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 345 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 225 PM PDT...RESCUE CREWS ARE PERFORMING SWIFT WATER RESCUES NEAR 
215 AND FLAMINGO WITH WATER UP TO THE WINDOWS OF CARS. MODERATE 
RAINFALL IS STILL OCCURRING AND THIS MAY AGGRAVATE EXISTING 
FLOODING. MOTORISTS ARE STRONGLY ADVISED TO AVOID THIS AREA.

LOCATIONS IMPACTED INCLUDE...
SUMMERLIN SOUTH AND SUMMERLIN WEST...AND AREAS NEAR THE 215 BELTWAY 
IN THE SOUTHWEST VALLEY.

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 3620 11541 3615 11525 3605 11524 3606 11533

$$

JGG
816 
WGUS75 KVEF 142224
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
324 PM PDT WED SEP 14 2011

NVC003-142234-
/O.CAN.KVEF.FF.W.0094.000000T0000Z-110914T2245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
324 PM PDT WED SEP 14 2011

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

HEAVY RAINFALL HAS ENDED AND LAW ENFORCEMENT REPORTS THAT FLASH 
FLOODING HAS ENDED IN THE AREA.  AREAS OF STANDING OR PONDED WATER 
WILL BE POSSIBLE ON AREA ROADWAYS IN THE SOUTHWESTERN LAS VEGAS 
VALLEY THROUGH THIS EVENING.

LAT...LON 3620 11541 3615 11525 3605 11524 3606 11533

$$

JGG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 14, 1:19 PM PDTFlash Flood WatchVEFClark, Lincoln, Nye7 hr
Sep 14, 1:27 PM PDTAreal Flood AdvisoryVEFClark111 min
Sep 14, 3:13 PM PDTAreal Flood AdvisoryVEFClark2 hr
Sep 14, 4:02 PM PDTAreal Flood AdvisoryVEFLincoln118 min
Sep 14, 4:35 PM PDTFlash Flood WarningVEFClark55 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.