Alert archive / Nevada / Flash Flood Warnings in 2014

Flash Flood Warning 83, NWS Las Vegas, NV

August 4, 2014Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 4, 2014, 2:21 PM PDT for Clark County, Nevada. It was in force for 3 hr. 6 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
Aug 4, 2014, 2:21 PM PDT (21:21 UTC)
Expired
Aug 4, 2014, 5:15 PM PDT
In force
3 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), 57 km from the middle of the area, began a volume at 21:22 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
Aug 4, 2:30 PM PDTHEAVY RAIN 1.264 Wsw Las Vegas Strip, NVA CLARK COUNTY REGIONAL FLOOD CONTROL DISTRICT GAUGE MEASURED 1.26 INCHES OF RAIN NEAR TROPICANA AND TORREY PINES WITH 0.75 INCH FALLING IN 15 MINUTES.
Aug 4, 2:43 PM PDTFLASH FLOOD5 Sw Las Vegas, NVPUBLIC REPORT FROM TWITTER OF WATER SEVERAL INCHES DEEP AT TWAIN AND DECATUR ROADS.
Aug 4, 3:17 PM PDTFLASH FLOOD4 Wsw Las Vegas, NVA SWIFWATER RESCUE WAS CONDUCTED AT DECATUR AND OAKEY.
Aug 4, 3:30 PM PDTFLASH FLOOD5 Wsw Las Vegas Strip, NVSOCIAL MEDIA VIDEO SHOWED WATER EST. 5 INCHES DEEP FLOWING OVER ROAD AT TROPICANA AND RAINBOW BLVD INTERSECTION. FLOOD CONTROL WASHES FULL IN THE AREA.
Aug 4, 3:30 PM PDTFLASH FLOODLas Vegas, NVA LARGE SECTION OF A CONCRETE BLOCK WALL WAS KNOCKED DOWN BY FLOODWATERS.
Aug 4, 4:15 PM PDTFLASH FLOOD4 Ssw Las Vegas, NVBROADCAST MEDIA TWEETED PICTURE OF WATER SEVERAL INCHES DEEP OVER THE ROADWAY AT THE INTERSECTION OF KOVAL LANE AND WINNICK AVE.

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 12:00Z, 9.4 hours before the alert went out and 40 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 2014-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 2014-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 16 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
6 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
932 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
16 m²/s²
0-3 km storm-relative helicity
25 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.

322 
WGUS55 KVEF 042121 RRA
FFWVEF
NVC003-050015-
/O.NEW.KVEF.FF.W.0083.140804T2121Z-140805T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
221 PM PDT MON AUG 4 2014

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 515 PM PDT

* AT 212 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR SPRING VALLEY...OR 6 MILES
  SOUTHWEST OF DOWNTOWN LAS VEGAS. THE STORM PRODUCING VERY HEAVY
  RAIN WAS NEARLY STATIONARY. RAINFALL GAGES IN THE AREA HAVE BEEN 
  SHOWING BETWEEN HALF AN INCH AND AN INCH OF RAIN IN HALF AN HOUR.

* LOCATIONS IMPACTED INCLUDE...
  DOWNTOWN LAS VEGAS...UNLV...SPRING VALLEY...THE STRIP AND NORTH LAS
  VEGAS AIRPORT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON ROADS...IN NORMALLY DRY WASHES AND LOW
LYING AREAS. NEVER TRY TO CROSS A FLOODED ROAD OR ENTER A FLOOD
CHANNEL. TURN AROUND...DONT DROWN!

REPORT FLOODING TO THE LAS VEGAS NATIONAL WEATHER SERVICE VIA
FACEBOOK OR TWITTER.

&&

LAT...LON 3623 11525 3618 11503 3602 11508 3613 11532

$$

ASG
2 follow-up statements
401 
WGUS75 KVEF 042145
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
245 PM PDT MON AUG 4 2014

NVC003-050015-
/O.CON.KVEF.FF.W.0083.000000T0000Z-140805T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
245 PM PDT MON AUG 4 2014

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 227 PM PDT...DOPPLER RADAR CONTINUED TO INDICATE A THUNDERSTORM 
THAT WAS PRODUCING FLASH FLOODING OVER DOWNTOWN LAS VEGAS. THIS 
THUNDERSTORM WAS NEARLY STATIONARY AND HAS ALREADY PRODUCED AN INCH 
OF RAIN OVER THE PAST HOUR. THERE HAVE ALSO BEEN REPORTS OF FLASH 
FLOODING IN THE WARNED AREA.  

LOCATIONS IMPACTED INCLUDE...
DOWNTOWN LAS VEGAS...THE STRIP AND NORTH LAS VEGAS AIRPORT.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON ROADS...IN NORMALLY DRY WASHES AND LOW
LYING AREAS. NEVER TRY TO CROSS A FLOODED ROAD OR ENTER A FLOOD
CHANNEL. TURN AROUND...DONT DROWN!

REPORT FLOODING TO THE LAS VEGAS NATIONAL WEATHER SERVICE VIA
FACEBOOK OR TWITTER.

&&

LAT...LON 3623 11525 3618 11503 3602 11508 3613 11532

$$

ASG
180 
WGUS75 KVEF 050011
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
511 PM PDT MON AUG 4 2014

NVC003-050019-
/O.EXP.KVEF.FF.W.0083.000000T0000Z-140805T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
511 PM PDT MON AUG 4 2014

...THE FLASH FLOOD WARNING WILL EXPIRE AT 515 PM PDT FOR CENTRAL
CLARK COUNTY...

HEAVY RAIN FROM EARLIER STORMS HAS MOVED OUT OF THE AREA...THEREFORE 
THE FLASH FLOOD WARNING HAS BEEN ALLOWED TO EXPIRE. HOWEVER...THERE 
ARE STILL MANY STREETS AROUND LAS VEGAS THAT STILL HAVE STANDING 
WATER WHICH WILL LIKELY CONTINUE THROUGH 600 PM. DRIVERS SHOULD 
STILL USE CAUTION WHILE DRIVING AROUND TOWN.

LAT...LON 3623 11525 3618 11503 3602 11508 3613 11532

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 5:32 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 3, 6:08 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 7:24 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 8:02 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 9:05 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 9:51 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 11:06 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 3, 11:17 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 3, 11:31 PM PDTFlash Flood WarningVEFClark3 hr
Aug 3, 11:35 PM PDTFlash Flood WarningVEFClark, Lincoln3 hr
Aug 3, 11:45 PM PDTAreal Flood AdvisoryVEFNye3 hr
Aug 3, 11:58 PM PDTFlash Flood WarningVEFClark3 hr
Aug 4, 2:44 AM PDTAreal Flood AdvisoryVEFNye2 hr
Aug 4, 3:25 AM PDTFlash Flood WarningVEFClark3 hr
Aug 4, 4:58 AM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 4, 12:06 PM PDTFlash Flood WarningVEFClark3 hr
Aug 4, 1:13 PM PDTAreal Flood AdvisoryVEFNye3 hr
Aug 4, 1:21 PM PDTAreal Flood AdvisoryVEFClark114 min
Aug 4, 1:47 PM PDTFlash Flood WarningVEFClark118 min
Aug 4, 2:16 PM PDTFlash Flood WarningVEFClark3 hr
Aug 4, 2:21 PM PDTFlash Flood WarningVEFNye114 min
Aug 4, 2:28 PM PDTFlash Flood WarningVEFClark3 hr
Aug 4, 2:57 PM PDTAreal Flood AdvisoryVEFClark, Lincoln5 hr
Aug 4, 3:45 PM PDTFlash Flood WarningVEFEsmeralda, Nye3 hr
Aug 4, 3:56 PM PDTFlash Flood WarningVEFLincoln3 hr
Aug 4, 4:16 PM PDTAreal Flood AdvisoryVEFClark, Nye3 hr

Nearby

Flash Flood Warnings in Nevada, 2014Every flash flood warning in 2014

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.