Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 54, NWS Las Vegas, NV

July 22, 2021Clark County, Lincoln County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 22, 2021, 3:21 PM PDT for Clark County, Lincoln County, Nevada. It was in force for 3 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 22, 2021, 3:21 PM PDT (22:21 UTC)
Expired: Jul 22, 2021, 6:30 PM PDT
In force: 3 hr
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties Clark County, NV, Lincoln County, NV

The radar

The Las Vegas radar (KESX), 145 km from the middle of the area, began a volume at 22:21 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, 10.4 hours before the alert went out and 88 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: 112 J/kg
Mixed-layer CIN: -243 J/kg
Mixed-layer LCL: 2637 m above ground
0-6 km bulk shear: 13 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: -4 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

815 
WGUS55 KVEF 222221
FFWVEF
NVC003-017-230130-
/O.NEW.KVEF.FF.W.0054.210722T2221Z-210723T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
321 PM PDT Thu Jul 22 2021

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  South Central Lincoln County in south central Nevada...
  North Central Clark County in southern Nevada...

* Until 630 PM PDT.

* At 321 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly along Highway 93 south of Alamo as well 
  as State Route 168 north of Moapa.

  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...
  Coyote Springs, Sr 168 Mile Marker 21, and Highway 93 south of 
  Alamo.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3687 11511 3708 11518 3722 11518 3732 11515
      3725 11488 3726 11478 3719 11464 3698 11480
      3687 11486 3685 11483 3681 11476 3676 11479
      3676 11504

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

$$

JV

2 follow-up statements

041 
WGUS75 KVEF 222308
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
408 PM PDT Thu Jul 22 2021

NVC003-017-230130-
/O.CON.KVEF.FF.W.0054.000000T0000Z-210723T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-Lincoln NV-
408 PM PDT Thu Jul 22 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT THIS 
EVENING FOR SOUTH CENTRAL LINCOLN AND NORTH CENTRAL CLARK COUNTIES...

At 408 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain continue to form and move across the warned area. Flash 
flooding is ongoing or expected to begin shortly along Highway 93 
south of Alamo as well as on State Route 168 north of Moapa.

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...
  Coyote Springs, Highway 93 south of Alamo, and Sr 168 Mile Marker 
  21 north of Moapa.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3687 11511 3708 11518 3722 11518 3732 11515
      3725 11488 3726 11478 3719 11464 3698 11480
      3687 11486 3685 11483 3681 11476 3676 11479
      3676 11504

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

$$

JV

975 
WGUS75 KVEF 230120
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
620 PM PDT Thu Jul 22 2021

NVC003-017-230130-
/O.EXP.KVEF.FF.W.0054.000000T0000Z-210723T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-Lincoln NV-
620 PM PDT Thu Jul 22 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 630 PM PDT THIS EVENING FOR 
SOUTH CENTRAL LINCOLN AND NORTH CENTRAL CLARK COUNTIES...

Flood waters have receded. 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 900 PM PDT for portions 
of northwest Arizona and Nevada.

LAT...LON 3687 11511 3708 11518 3722 11518 3732 11515
      3725 11488 3726 11478 3719 11464 3698 11480
      3687 11486 3685 11483 3681 11476 3676 11479
      3676 11504

$$

JV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 22, 10:18 AM PDT	Flash Flood Watch	VEF	Clark, Lincoln, Nye	11 hr
Jul 22, 12:53 PM PDT	Severe Thunderstorm Warning	VEF	Clark	26 min
Jul 22, 1:31 PM PDT	Severe Thunderstorm Warning	VEF	Clark	44 min
Jul 22, 1:35 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Lincoln	3 hr
Jul 22, 1:36 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 22, 1:49 PM PDT	Severe Thunderstorm Warning	VEF	Clark	41 min
Jul 22, 2:20 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 22, 2:32 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Clark	3 hr
Jul 22, 3:03 PM PDT	Severe Thunderstorm Warning	VEF	Clark, Lincoln	42 min
Jul 22, 4:09 PM PDT	Severe Thunderstorm Warning	VEF	Clark	51 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.