Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 69, NWS Las Vegas, NV

July 26, 2021Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 26, 2021, 10:20 AM PDT for Clark County, Nevada. It was in force for 3 hr. 2 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: Jul 26, 2021, 10:20 AM PDT (17:20 UTC)
Expired: Jul 26, 2021, 1:30 PM PDT
In force: 3 hr
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Clark County, NV

What was reported inside it

Time	Report	Where	Remark
Jul 26, 11:30 AM PDT	FLASH FLOOD	2 Ene Red Rock Canyon, NV	VIDEO OF FLOWING WATER OVER CALICO BASIN ROAD WITH MUD...BOULDERS...AND DEBRIS ON THE ROADWAY. REPORT VIA TWITTER VIDEO.
Jul 26, 12:36 PM PDT	FLASH FLOOD	Enterprise, NV	WATER FLOWING ACROSS RAINBOW AT BLUE DIAMOND. ROAD IS CLOSED.

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, 5.3 hours before the alert went out and 38 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 467 J/kg
Mixed-layer CIN: -144 J/kg
Mixed-layer LCL: 1095 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -37 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.3

Open this sounding in Storm Lab

The text

As transmitted.

283 
WGUS55 KVEF 261720
FFWVEF
NVC003-262030-
/O.NEW.KVEF.FF.W.0069.210726T1720Z-210726T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
1020 AM PDT Mon Jul 26 2021

The National Weather Service in Las Vegas has issued a

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

* Until 130 PM PDT.

* At 1020 AM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across Red Rock Canyon and across Southwest Las Vegas. 
  Between 0.5 and 1 inch of rain has fallen. Flash flooding is 
  ongoing or expected to begin shortly. 1 inch of rain was measured 
  at Red Rock Canyon in less than 30 minutes.

  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...
  Las Vegas, Blue Diamond, Mountains Edge, Spring Valley, Summerlin, 
  Enterprise, Red Rock Canyon, Southern Highlands, Red Rock Canyon 
  Campground, Spring Mountain Ranch, Rocky Gap Campground and Sloan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3620 11549 3622 11539 3622 11538 3616 11532
      3601 11519 3597 11516 3593 11516 3589 11520
      3594 11535 3600 11543 3615 11553

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

$$

CO

3 follow-up statements

668 
WGUS75 KVEF 261811
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1111 AM PDT Mon Jul 26 2021

NVC003-262030-
/O.CON.KVEF.FF.W.0069.000000T0000Z-210726T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
1111 AM PDT Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 PM PDT THIS 
AFTERNOON FOR WEST CENTRAL CLARK COUNTY...

At 1111 AM PDT, Heavy rain has begun to lift west and away from Red 
Rock Canyon and southwest Las Vegas. However, several rain gauges 
near Red Rock picked up between 1 and 1.5 inches of rain in less 
than an hour. Additional rain gauges in Southwest Las Vegas picked 
up near .75 inches of rain. Local washes and drainages will 
experience high flows through the early afternoon.

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...
  Las Vegas, Blue Diamond, Mountains Edge, Spring Valley, Summerlin, 
  Enterprise, Red Rock Canyon, Southern Highlands, Red Rock Canyon 
  Campground, Spring Mountain Ranch, Rocky Gap Campground and Sloan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3620 11549 3622 11539 3622 11538 3616 11532
      3601 11519 3597 11516 3593 11516 3589 11520
      3594 11535 3600 11543 3615 11553

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

$$

CO

580 
WGUS75 KVEF 261906
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1206 PM PDT Mon Jul 26 2021

NVC003-262030-
/O.CON.KVEF.FF.W.0069.000000T0000Z-210726T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
1206 PM PDT Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 130 PM PDT THIS 
AFTERNOON FOR WEST CENTRAL CLARK COUNTY...

At 1206 PM PDT, Heaviest rainfall around Red Rock Canyon has begun 
to ease. However, a rain gauge in Brownstone Canyon totaled 2.44 
inches since 10 am and Red Rock Canyon near 2 inches. Water flows 
over local roads around Calico Basin are likely as well as high 
streamflows into the Red Rock Detention Basin.

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...
  Las Vegas, Blue Diamond, Mountains Edge, Spring Valley, Summerlin, 
  Enterprise, Red Rock Canyon, Southern Highlands, Red Rock Canyon 
  Campground, Spring Mountain Ranch, Rocky Gap Campground and Sloan.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3620 11549 3622 11539 3622 11538 3616 11532
      3601 11519 3597 11516 3593 11516 3589 11520
      3594 11535 3600 11543 3615 11553

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

$$

CO

577 
WGUS75 KVEF 262023
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
123 PM PDT Mon Jul 26 2021

NVC003-262033-
/O.EXP.KVEF.FF.W.0069.000000T0000Z-210726T2030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
123 PM PDT Mon Jul 26 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 130 PM PDT THIS AFTERNOON FOR 
WEST CENTRAL CLARK COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

A Flash Flood Watch remains in effect until 1100 PM PDT Monday for 
portions of southeast California and Nevada.

LAT...LON 3620 11549 3622 11539 3622 11538 3616 11532
      3601 11519 3597 11516 3593 11516 3589 11520
      3594 11535 3600 11543 3615 11553

$$

CO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 5:12 PM PDT	Dust Storm Warning	VEF	Clark	63 min
Jul 25, 5:37 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Lincoln	3 hr
Jul 25, 6:01 PM PDT	Severe Thunderstorm Warning	VEF	Clark	59 min
Jul 25, 6:06 PM PDT	Severe Thunderstorm Warning	VEF	Lincoln	39 min
Jul 25, 7:08 PM PDT	Severe Thunderstorm Warning	VEF	Clark	52 min
Jul 25, 7:57 PM PDT	Severe Thunderstorm Warning	VEF	Clark, Lincoln	63 min
Jul 25, 8:09 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 25, 8:59 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 25, 8:59 PM PDT	Severe Thunderstorm Warning	VEF	Clark, Nye	61 min
Jul 25, 9:55 PM PDT	Severe Thunderstorm Warning	VEF	Clark, Nye	50 min
Jul 26, 10:44 AM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 26, 11:32 AM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark, Nye	4 hr
Jul 26, 12:29 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Nye	3 hr
Jul 26, 12:40 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Nye	3 hr
Jul 26, 1:28 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Lincoln	3 hr
Jul 26, 2:05 PM PDT	Severe Thunderstorm Warning	VEF	Lincoln	40 min
Jul 26, 4:30 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Lincoln	2 hr
Jul 26, 4:34 PM PDT	Severe Thunderstorm Warning	VEF	Lincoln	41 min

Nearby

Flash Flood Warnings in Nevada, 2021 Every 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.