Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 128, NWS Las Vegas, NV

August 31, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 31, 2021, 7:58 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: Aug 31, 2021, 7:58 PM MST (02:58 UTC)
Expired: Aug 31, 2021, 11:00 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), 77 km from the middle of the area, began a volume at 03:02 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 00:00Z, 3.0 hours before the alert went out and 168 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 0 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

108 
WGUS55 KVEF 010258
FFWVEF
AZC015-010600-
/O.NEW.KVEF.FF.W.0128.210901T0258Z-210901T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
758 PM PDT Tue Aug 31 2021

The National Weather Service in Las Vegas has issued a

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

* Until 1100 PM MST.

* At 758 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...
  Windy Point Campground, Chloride, Packsaddle Campground and New 
  Kingman-Butler.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 11427 3547 11418 3553 11405 3540 11398
      3531 11400 3523 11413

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

$$

JV

2 follow-up statements

680 
WGUS75 KVEF 010342
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
842 PM PDT Tue Aug 31 2021

AZC015-010600-
/O.CON.KVEF.FF.W.0128.000000T0000Z-210901T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
842 PM MST Tue Aug 31 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 11 PM MST THIS 
EVENING FOR SOUTHWESTERN MOHAVE COUNTY...

At 842 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area have subsided, but light to moderate 
rain continues to fall. 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...
  Windy Point Campground, Chloride, Packsaddle Campground and New 
  Kingman-Butler.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 11427 3547 11418 3553 11405 3540 11398
      3531 11400 3523 11413

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

$$

JV

006 
WGUS75 KVEF 010558
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1058 PM PDT Tue Aug 31 2021

AZC015-010608-
/O.EXP.KVEF.FF.W.0128.000000T0000Z-210901T0600Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
1058 PM MST Tue Aug 31 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 11 PM MST THIS EVENING FOR 
SOUTHWESTERN MOHAVE COUNTY...

Flooding is no longer expected to pose a threat. Light to moderate 
rain continues over the warned area. Please continue to heed 
remaining road closures, if applicable.

A Flash Flood Watch remains in effect until 500 AM MST Thursday for 
portions of northwest Arizona, southeast California and southern 
Nevada.

LAT...LON 3541 11427 3547 11418 3553 11405 3540 11398
      3531 11400 3523 11413

$$

JV

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 7:11 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 31, 9:38 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Sep 1, 1:08 AM MST	Areal Flood Advisory	VEF	Mohave	3 hr
Sep 1, 10:15 AM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	116 min

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.