Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 98, NWS Las Vegas, NV

August 29, 2017Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 29, 2017, 1:48 PM PDT for Clark County, Nevada. It was in force for 3 hr. 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
Aug 29, 2017, 1:48 PM PDT (20:48 UTC)
Expired
Aug 29, 2017, 4:45 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), 91 km from the middle of the area, began a volume at 20:51 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 29, 2:30 PM PDTFLASH FLOOD7 E Mt. Charleston, NVPUBLIC WORKS REPORTS DEBRIS IN ROADS IN MT CHARLESTON SUB-DIVISION VIA WEBEOC.

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, 8.8 hours before the alert went out and 10 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 2017-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 144 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 2017-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -52 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
144 J/kg
Mixed-layer CIN
-344 J/kg
Mixed-layer LCL
3484 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
-52 m²/s²
0-3 km storm-relative helicity
46 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted.

960 
WGUS55 KVEF 292048
FFWVEF
NVC003-292345-
/O.NEW.KVEF.FF.W.0098.170829T2048Z-170829T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
148 PM PDT TUE AUG 29 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  West central Clark County in southern Nevada...

* Until 445 PM PDT

* At 144 PM PDT, Doppler radar continued to indicate heavy rain from 
  thunderstorms and emergency management officials reported a few 
  inches of debris flowing across Kyle and Lee Canyon roads in the 
  Spring Mountains. Between 1 and 2 inches of rain has already 
  fallen and more rain can be expected leading to increased flash 
  flooding.

* Some locations that will experience flooding include...
  Rainbow Canyon and sections of roads in Kyle Canyon and Lee Canyon.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3628 11543 3619 11561 3626 11579 3637 11570
      3641 11556

$$

JA
1 follow-up statement
819 
WGUS75 KVEF 292230
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
330 PM PDT TUE AUG 29 2017

NVC003-292239-
/O.CAN.KVEF.FF.W.0098.000000T0000Z-170829T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
330 PM PDT TUE AUG 29 2017

...THE FLASH FLOOD WARNING FOR WEST CENTRAL CLARK COUNTY IS
CANCELLED...

The heavy rain has on Mount Charleston ended. Flood waters have 
receded. Flooding is no longer expected to pose a threat. Please 
continue to heed any remaining road and campground closures.

LAT...LON 3628 11543 3619 11561 3626 11579 3637 11570
      3641 11556

$$

AA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 1:22 PM PDTAreal Flood AdvisoryVEFClark3 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; radar from the NEXRAD Level II archive.