Alert archive / Nevada / Flash Flood Warnings in 2021

Flash Flood Warning 87, NWS Las Vegas, NV

July 30, 2021Clark County, Nevada; San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 30, 2021, 4:07 PM PDT for Clark County, Nevada; San Bernardino County, California. 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 30, 2021, 4:07 PM PDT (23:07 UTC)
Expired: Jul 30, 2021, 7:15 PM PDT
In force: 3 hr
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

Counties San Bernardino County, CA, Clark County, NV

The radar

The Las Vegas radar (KESX), 66 km from the middle of the area, began a volume at 23:07 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, 11.1 hours before the alert went out and 63 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: 17 J/kg
Mixed-layer CIN: -233 J/kg
Mixed-layer LCL: 2114 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: -15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

360 
WGUS55 KVEF 302307
FFWVEF
CAC071-NVC003-310215-
/O.NEW.KVEF.FF.W.0087.210730T2307Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
407 PM PDT Fri Jul 30 2021

The National Weather Service in Las Vegas has issued a

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

* Until 715 PM PDT.

* At 407 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 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...
  Sandy Valley and Goodsprings.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3581 11564 3587 11572 3598 11562 3583 11544
      3568 11551 3572 11566

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

$$

DB

2 follow-up statements

677 
WGUS75 KVEF 310042
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
542 PM PDT Fri Jul 30 2021

CAC071-NVC003-310215-
/O.CON.KVEF.FF.W.0087.000000T0000Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
542 PM PDT Fri Jul 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM PDT THIS 
EVENING FOR SAN BERNARDINO AND WEST CENTRAL CLARK COUNTIES...

At 542 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. 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...
  Sandy Valley and Goodsprings.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3581 11564 3587 11572 3598 11562 3583 11544
      3568 11551 3572 11566

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

$$

BKP

350 
WGUS75 KVEF 310212 RRA
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
712 PM PDT Fri Jul 30 2021

CAC071-NVC003-310222-
/O.EXP.KVEF.FF.W.0087.000000T0000Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
712 PM PDT Fri Jul 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 715 PM PDT THIS EVENING FOR 
SAN BERNARDINO AND WEST CENTRAL CLARK COUNTIES...

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 500 AM PDT Sunday for 
portions of northwest Arizona, southeast California and Nevada.

LAT...LON 3581 11564 3587 11572 3598 11562 3583 11544
      3568 11551 3572 11566

$$

BKP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 6:04 PM PDT	Severe Thunderstorm Warning	VEF	Clark	56 min
Jul 29, 8:22 PM PDT	Areal Flood Advisory	VEF	Clark	3 hr
Jul 30, 2:39 PM PDT	Areal Flood Advisory	VEF	Clark	3 hr
Jul 30, 1:14 PM PDT	Severe Thunderstorm Warning	VEF	San Bernardino	61 min
Jul 30, 2:48 PM PDT	Flash Flood Warning Considerable damage threat	VEF	San Bernardino	3 hr
Jul 30, 2:53 PM PDT	Areal Flood Advisory	VEF	Inyo	3 hr
Jul 30, 3:56 PM PDT	Flash Flood Warning Considerable damage threat	VEF	Inyo	5 hr

Nearby

Flash Flood Warnings in Nevada, 2021 Flash Flood Warnings in California, 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.