Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 19, NWS Las Vegas, NV

July 18, 2021Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 18, 2021, 1:05 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: Jul 18, 2021, 1:05 PM PDT (20:05 UTC)
Expired: Jul 18, 2021, 4:15 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

The radar

The Las Vegas radar (KESX), 117 km from the middle of the area, began a volume at 20:05 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

Time	Report	Where	Remark
Jul 18, 1:30 PM PDT	FLASH FLOOD	12 Ssw Indian Springs, NV	CORRECTS PREVIOUS FLASH FLOOD REPORT FROM 12 SSW INDIAN SPRINGS. FLOODING IN COLD CREEK NV RESULTED IN THE SHOULDERS OF SOME ROADS BEING WASHED OUT. TIME ESTIMATED FROM RADAR.

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, 8.1 hours before the alert went out and 22 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: 424 J/kg
Mixed-layer CIN: -164 J/kg
Mixed-layer LCL: 2704 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: -9 m²/s²
0-3 km storm-relative helicity: 48 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

420 
WGUS55 KVEF 182005
FFWVEF
NVC003-182315-
/O.NEW.KVEF.FF.W.0019.210718T2005Z-210718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
105 PM PDT Sun Jul 18 2021

The National Weather Service in Las Vegas has issued a

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

* Until 415 PM PDT.

* At 105 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly including Lee Canyon Rd, Kyle Canyon Rd, 
  and Cold Creek Rd.

  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...
  Indian Springs, Willow Creek Campground, Mcwilliams Campground and 
  Dolomite Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3662 11589 3662 11561 3646 11537 3630 11567
      3644 11588

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

$$

JV

3 follow-up statements

649 
WGUS75 KVEF 182036
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
136 PM PDT Sun Jul 18 2021

NVC003-182315-
/O.CON.KVEF.FF.W.0019.000000T0000Z-210718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
136 PM PDT Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM PDT THIS 
AFTERNOON FOR NORTHWESTERN CLARK COUNTY...

At 136 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Flash flooding is ongoing or expected 
to begin shortly on Lee Canyon Rd, Kyle Canyon Rd, and Cold Creek 
Rd, as well as portions of Highway 95 from Las Vegas north to 
Highway 160. Flooding in Indian Springs possible.

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...
  Indian Springs, Willow Creek Campground, Mcwilliams Campground and 
  Dolomite Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3662 11589 3662 11561 3646 11537 3630 11567
      3644 11588

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

$$

JV

460 
WGUS75 KVEF 182116
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
216 PM PDT Sun Jul 18 2021

NVC003-182315-
/O.CON.KVEF.FF.W.0019.000000T0000Z-210718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
216 PM PDT Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM PDT THIS 
AFTERNOON FOR NORTHWESTERN CLARK COUNTY...

At 216 PM PDT, Though rainfall has largely ceased in the warned 
area, the threat of flash flooding continues on Lee Canyon Rd, Kyle 
Canyon Rd, and Cold Creek Rd, as well as portions of Highway 95 from 
Las Vegas north to Highway 160 including Indian Springs.

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...
  Indian Springs, Willow Creek Campground, Mcwilliams Campground and 
  Dolomite Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3662 11589 3662 11561 3646 11537 3630 11567
      3644 11588

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

$$

JV

769 
WGUS75 KVEF 182308
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
408 PM PDT Sun Jul 18 2021

NVC003-182318-
/O.EXP.KVEF.FF.W.0019.000000T0000Z-210718T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
408 PM PDT Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 415 PM PDT THIS AFTERNOON FOR 
NORTHWESTERN CLARK COUNTY...

The heavy rain has ended. Widespread flash flooding is no longer a 
threat, though ponding and debris over roadways may persist. Heed 
all road closures, if applicable.

LAT...LON 3662 11589 3662 11561 3646 11537 3630 11567
      3644 11588

$$

JV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 5:33 PM PDT	Severe Thunderstorm Warning	VEF	Clark	57 min
Jul 18, 1:27 PM PDT	Areal Flood Advisory	VEF	Clark	3 hr
Jul 18, 3:46 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	2 hr
Jul 18, 4:01 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	119 min
Jul 18, 4:33 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr

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; radar from the NEXRAD Level II archive.