Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 96, NWS Las Vegas, NV

August 1, 2021Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 1, 2021, 11:37 AM PDT for Clark County, Nevada. It was in force for 114 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 1, 2021, 11:37 AM PDT (18:37 UTC)
Expired
Aug 1, 2021, 1:31 PM PDT
In force
114 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Damage threat
Considerable
Flood severity
None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 78 km from the middle of the area, began a volume at 18:37 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 6.6 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 2021-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 680 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 2021-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.193958Sfc1 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
680 J/kg
Mixed-layer CIN
-99 J/kg
Mixed-layer LCL
1983 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
27 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

625 
WGUS55 KVEF 011837
FFWVEF
NVC003-012145-
/O.NEW.KVEF.FF.W.0096.210801T1837Z-210801T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
1137 AM PDT Sun Aug 1 2021

The National Weather Service in Las Vegas has issued a

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

* Until 245 PM PDT.

* At 1137 AM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain over the Spring Mountains and Red Rock Canyon. Flash 
  flooding is ongoing or expected to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding.

  SOURCE...Radar.

  IMPACT...Life-threatening flash flooding of low-water
           crossings, creeks, normally dry washes and roads.

* Some locations that will experience flash flooding include...
  Rainbow Canyon, Red Rock Canyon, Spring Mountains, Mt. Charleston, 
  Summerlin, Rocky Gap Campground, Lovell Canyon Campground, Kyle 
  Canyon Campground, Fletcher View Campground, Hilltop Campground, 
  Spring Mountain Ranch, Red Rock Canyon Campground and Mary Jane 
  Falls Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3633 11537 3607 11536 3607 11551 3630 11575

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JS
1 follow-up statement
870 
WGUS75 KVEF 012031
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
131 PM PDT Sun Aug 1 2021

NVC003-012041-
/O.CAN.KVEF.FF.W.0096.000000T0000Z-210801T2145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
131 PM PDT Sun Aug 1 2021

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

Thunderstorms that produced heavy rain earlier today have ended and 
flooding is not expected to pose a threat at this time. Please 
continue to heed any road closures.

LAT...LON 3633 11537 3607 11536 3607 11551 3630 11575

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 9:33 AM PDTFlash Flood WatchVEFClark, Lincoln8 hr
Aug 1, 10:59 AM PDTSevere Thunderstorm WarningVEFClark46 min

Nearby

Flash Flood Warnings in Nevada, 2021Every flash flood warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.