Alert archive / Nevada / Flash Flood Warnings in 2012

Flash Flood Warning 9, NWS Las Vegas, NV

July 13, 2012Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 13, 2012, 4:24 PM PDT for Clark County, Nevada. It was in force for 41 min. 1 report 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
Jul 13, 2012, 4:24 PM PDT (23:24 UTC)
Expired
Jul 13, 2012, 5:05 PM PDT
In force
41 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), 25 km from the middle of the area, began a volume at 23:25 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
Jul 13, 5:15 PM PDTHEAVY RAIN 1.8915 Sw Boulder City, NVAN AUTOMATED GAUGE 15 MILES SOUTHWEST OF BOULDER CITY MEASURED A STORM TOTAL OF 1.89 INCHES OF RAIN WITH 1.10 INCHES IN 90 MINUTES.

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, 11.4 hours before the alert went out and 70 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 2012-07-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1 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 12:00Z on 2012-07-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 25 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
1 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
2268 m above ground
0-6 km bulk shear
29 kt
0-1 km storm-relative helicity
25 m²/s²
0-3 km storm-relative helicity
44 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.

519 
WGUS55 KVEF 132324
FFWVEF
NVC003-140130-
/O.NEW.KVEF.FF.W.0009.120713T2324Z-120714T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
424 PM PDT FRI JUL 13 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 630 PM PDT.

* AT 421 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A THUNDERSTORM MOVING INTO SEVEN HILLS...GREEN
  VALLEY AND HENDERSON. THE STORM WAS MOVING NORTHEAST AT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...
  HENDERSON...BOULDER CITY...SEVEN HILLS...SILVERADO RANCH...GREEN
  VALLEY...RAILROAD PASS...EAST LAS VEGAS AND SAM BOYD STADIUM.

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 3612 11504 3597 11479 3550 11507 3553 11523
      3586 11507 3594 11535

$$

JA
1 follow-up statement
250 
WGUS75 KVEF 140005
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
505 PM PDT FRI JUL 13 2012

NVC003-140006-
/O.CAN.KVEF.FF.W.0009.000000T0000Z-120714T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
505 PM PDT FRI JUL 13 2012

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

HEAVY RAINFALL PREVIOUSLY FALLING OVER THE SOUTHERN PART OF THE
SOUTHEAST LAS VEGAS VALLEY HAS DISSIPATED SINCE 430 PM AND THE 
THREAT FOR FLASH FLOODING HAS DIMINISHED CONSIDERABLY. AUTOMATED 
GAGES ALONG THE FOOTHILLS PICKED UP BETWEEN A THIRD AND HALF AN INCH 
WHILE AREAS NEAR THE 215 BELTWAY ONLY RECEIVED AROUND A TENTH OF AN 
INCH OF RAIN OR LESS. SOME SHALLOW RUNOFF OR PONDING OF WATER ON 
SOME ROADWAYS MAY BE OBSERVED IN THE SOUTHEAST PART OF THE 
VALLEY...BUT SIGNIFICANT FLASH FLOODING IS NO LONGER AN IMMEDIATE 
THREAT. THE FLASH FLOOD WARNING HAS BEEN CANCELLED.


LAT...LON 3612 11504 3597 11479 3550 11507 3553 11523
      3586 11507 3594 11535

$$

JA

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 12, 7:14 PM PDTFlash Flood WarningVEFLincoln104 min
Jul 13, 3:38 PM PDTFlash Flood WarningVEFClark112 min

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.