Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 77, NWS Las Vegas, NV

August 4, 2017Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 4, 2017, 1:27 PM PDT for Clark County, Nevada. It was in force for 3 hr. 3 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, 2017, 1:27 PM PDT (20:27 UTC)
Expired
Aug 4, 2017, 4:30 PM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Clark County, NV

What was reported inside it

TimeReportWhereRemark
Aug 4, 1:51 PM PDTFLASH FLOODMt. Charleston, NVFLASH FLOODING AND DEBRIS FLOW ALONG HWY 157, THE FOREST SERVICE CAMPGROUND AND RAINBOW SUBDIVISION IS CURRENTLY OCCURING.
Aug 4, 3:32 PM PDTFLASH FLOOD7 W Red Rock Canyon, NVLOVELL CANYON ROAD CLOSED DUE TO DEBRIS AND FLASH FLOODING.
Aug 4, 4:33 PM PDTFLASH FLOOD6 E Mt. Charleston, NVHARRIS SPRINGS ROAD WASHED OUT FROM FLASH FLOODING.

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, 8.5 hours before the alert went out and 18 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 2017-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 200 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 2017-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 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
200 J/kg
Mixed-layer CIN
-59 J/kg
Mixed-layer LCL
1855 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
15 m²/s²
0-3 km storm-relative helicity
15 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

520 
WGUS55 KVEF 042027
FFWVEF
NVC003-042330-
/O.NEW.KVEF.FF.W.0077.170804T2027Z-170804T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
127 PM PDT FRI AUG 4 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Northwestern Clark County in southern Nevada...

* Until 430 PM PDT

* At 125 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across portions of the Spring Mountains including Mt. 
  Charleston. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Rainbow Canyon, Spring Mountains, Mt. Charleston, Mahogany Grove
  Campground, Mary Jane Falls Campground, Kyle Canyon Campground,
  Dolomite Campground, Fletcher View Campground, Mcwilliams
  Campground, Lovell Canyon Campground, Willow Creek Campground and
  Hilltop Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3632 11590 3644 11590 3648 11550 3623 11539
      3606 11572

$$

ASG
2 follow-up statements
758 
WGUS75 KVEF 042131
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
231 PM PDT FRI AUG 4 2017

NVC003-042330-
/O.CON.KVEF.FF.W.0077.000000T0000Z-170804T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
231 PM PDT FRI AUG 4 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR
NORTHWESTERN CLARK COUNTY...

At 228 PM PDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain portions of the Spring Mountains 
including Mt. Charleston. Rainbow Canyon and Harris Canyon automated 
rain gauges have already received nearly 2 inches of rainfall today 
and additional heavy rain will likely occur. Flash flooding is 
likely.

Some locations that will experience flooding include...
Rainbow Canyon, Spring Mountains, Mt. Charleston, Mahogany Grove
Campground, Mary Jane Falls Campground, Kyle Canyon Campground,
Dolomite Campground, Fletcher View Campground, Mcwilliams Campground,
Lovell Canyon Campground, Willow Creek Campground and Hilltop
Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

&&

LAT...LON 3632 11590 3644 11590 3648 11550 3623 11539
      3606 11572

$$

ASG
408 
WGUS75 KVEF 042326
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
426 PM PDT FRI AUG 4 2017

NVC003-042334-
/O.EXP.KVEF.FF.W.0077.000000T0000Z-170804T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
426 PM PDT FRI AUG 4 2017

...THE FLASH FLOOD WARNING FOR NORTHWESTERN CLARK COUNTY WILL EXPIRE
AT 430 PM PDT...

Heavy rain has ended over the Spring Mountains. Flash flooding is no 
longer expected to pose a threat. However, runoff from earlier heavy 
rains will likely impact the area through the remainder of the 
afternoon. Please continue to heed any remaining road closures.

LAT...LON 3632 11590 3644 11590 3648 11550 3623 11539
      3606 11572

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 3, 7:34 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 4, 1:17 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 4, 2:01 PM PDTAreal Flood AdvisoryVEFNye3 hr
Aug 4, 4:46 PM PDTFlash Flood WarningVEFClark, Nye3 hr

Nearby

Flash Flood Warnings in Nevada, 2017Every flash flood warning in 2017

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.