Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 88, NWS Las Vegas, NV

July 30, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 30, 2021, 4:17 PM MST for Mohave County, Arizona. 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, 4:17 PM MST (23:17 UTC)
Expired: Jul 30, 2021, 7:15 PM MST
In force: 3 hr
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Mohave County, AZ

The radar

The Las Vegas radar (KESX), 93 km from the middle of the area, began a volume at 23:15 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, 11.3 hours before the alert went out and 188 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.

520 
WGUS55 KVEF 302317
FFWVEF
AZC015-310215-
/O.NEW.KVEF.FF.W.0088.210730T2317Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Southwestern Mohave County in northwestern Arizona...

* Until 715 PM MST.

* At 417 PM MST, 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...
  Oatman Highway and Golden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3521 11447 3528 11418 3485 11392 3475 11423
      3491 11436

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

$$

DB

2 follow-up statements

278 
WGUS75 KVEF 310044
FFSVEF

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

AZC015-310215-
/O.CON.KVEF.FF.W.0088.000000T0000Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
544 PM MST Fri Jul 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM MST THIS 
EVENING FOR SOUTHWESTERN MOHAVE COUNTY...

At 544 PM MST, 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...
  Oatman Highway and Golden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3521 11447 3528 11418 3485 11392 3475 11423
      3491 11436

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

$$

BKP

348 
WGUS75 KVEF 310212
FFSVEF

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

AZC015-310222-
/O.EXP.KVEF.FF.W.0088.000000T0000Z-210731T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
712 PM MST Fri Jul 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 715 PM MST THIS EVENING FOR 
SOUTHWESTERN MOHAVE 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 500 AM MST Sunday for 
portions of northwest Arizona, southeast California and Nevada.

LAT...LON 3521 11447 3528 11418 3485 11392 3475 11423
      3491 11436

$$

BKP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 29, 5:12 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	2 hr
Jul 29, 6:04 PM MST	Severe Thunderstorm Warning	VEF	Mohave	56 min
Jul 30, 12:04 PM MST	Areal Flood Advisory	VEF	Mohave	3 hr
Jul 30, 12:36 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 30, 1:14 PM MST	Severe Thunderstorm Warning	VEF	Mohave	61 min
Jul 30, 2:22 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr

Nearby

Flash Flood Warnings in Arizona, 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.