Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 45, NWS Las Vegas, NV

July 21, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 21, 2021, 4:18 PM MST for Mohave County, Arizona. It was in force for 2 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 21, 2021, 4:18 PM MST (23:18 UTC)
Expired: Jul 21, 2021, 6:20 PM MST
In force: 2 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), 110 km from the middle of the area, began a volume at 23:16 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

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 11.3 hours before the alert went out and 187 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: 77 J/kg
Mixed-layer CIN: -129 J/kg
Mixed-layer LCL: 1785 m above ground
0-6 km bulk shear: 8 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: -11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

209 
WGUS55 KVEF 212318
FFWVEF
AZC015-220230-
/O.NEW.KVEF.FF.W.0045.210721T2318Z-210722T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
418 PM PDT Wed Jul 21 2021

The National Weather Service in Las Vegas has issued a

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

* Until 730 PM MST.

* At 418 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Emergency Management also 
  reported Flash Flooding at DW Ranch Road. 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...
  Kingman, Dw Ranch Road and Blake Ranch Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3511 11389 3516 11394 3518 11394 3525 11394
      3526 11385 3523 11379 3518 11375 3514 11375

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

$$

AN

2 follow-up statements

306 
WGUS75 KVEF 220039
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
539 PM PDT Wed Jul 21 2021

AZC015-220230-
/O.CON.KVEF.FF.W.0045.000000T0000Z-210722T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
539 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 730 PM MST THIS 
EVENING FOR SOUTHERN MOHAVE COUNTY...

At 539 PM MST, Doppler radar indicated that heavy rainfall had ended 
for this area with only light rain expected in the next hour. 
However, continued runoff from this earlier activity may still be 
resulting in flooding, specifically of DW Ranch Road.

HAZARD...Life-threatening flash flooding of DW Ranch Road and
         other nearby roadways or washes.

SOURCE...Radar and county officials.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Kingman, DW Ranch Road and Blake Ranch Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3511 11389 3516 11394 3518 11394 3525 11394
      3526 11385 3523 11379 3518 11375 3514 11375

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

$$

TB

798 
WGUS75 KVEF 220120
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
620 PM PDT Wed Jul 21 2021

AZC015-220130-
/O.CAN.KVEF.FF.W.0045.000000T0000Z-210722T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
620 PM MST Wed Jul 21 2021

...FLASH FLOOD WARNING IS CANCELLED FOR SOUTHERN MOHAVE COUNTY...

The heavy rain has ended and local officials have confirmed that DW 
Ranch Road is no longer experiencing flooding. Only light to 
moderate rainfall is expected and is not expected to produce 
additional flooding. Thus the warning is cancelled.

LAT...LON 3511 11389 3516 11394 3518 11394 3525 11394
      3526 11385 3523 11379 3518 11375 3514 11375

$$

TB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 6:47 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 21, 12:07 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	4 hr
Jul 21, 1:24 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	5 hr
Jul 21, 2:25 PM MST	Areal Flood Advisory	VEF	Mohave	2 hr
Jul 21, 3:35 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 21, 4:03 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	2 hr
Jul 21, 4:56 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.