Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 30, NWS Las Vegas, NV

July 19, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 19, 2021, 2:31 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 19, 2021, 2:31 PM MST (21:31 UTC)
Expired: Jul 19, 2021, 5:30 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 21:36 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, 9.5 hours before the alert went out and 171 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: 127 J/kg
Mixed-layer CIN: -232 J/kg
Mixed-layer LCL: 1964 m above ground
0-6 km bulk shear: 20 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

395 
WGUS55 KVEF 192131
FFWVEF
AZC015-200030-
/O.NEW.KVEF.FF.W.0030.210719T2131Z-210720T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
231 PM PDT Mon Jul 19 2021

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  West Central Mohave County in northwestern Arizona...

* Until 530 PM MST.

* At 231 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the Black Mountains near Golden Valley. 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...
  Golden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3540 11441 3539 11426 3515 11411 3498 11417
      3498 11429 3503 11437 3511 11438 3533 11444

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

$$

CP

2 follow-up statements

437 
WGUS75 KVEF 192214
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
314 PM PDT Mon Jul 19 2021

AZC015-200030-
/O.CON.KVEF.FF.W.0030.000000T0000Z-210720T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
314 PM MST Mon Jul 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM MST THIS 
AFTERNOON FOR WEST CENTRAL MOHAVE COUNTY...

At 314 PM MST, Doppler radar indicated thunderstorms are continuing 
to develop and train in and around Golden Valley. These 
thunderstorms are producing heavy rain. 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...
  Golden Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3540 11441 3539 11426 3515 11411 3498 11417
      3498 11429 3503 11437 3511 11438 3533 11444

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

$$

CP

141 
WGUS75 KVEF 200029
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
529 PM PDT Mon Jul 19 2021

AZC015-200039-
/O.EXP.KVEF.FF.W.0030.000000T0000Z-210720T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
529 PM MST Mon Jul 19 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 530 PM MST THIS AFTERNOON FOR 
WEST CENTRAL 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 800 PM MST for a portion 
of northwest Arizona.

LAT...LON 3540 11441 3539 11426 3515 11411 3498 11417
      3498 11429 3503 11437 3511 11438 3533 11444

$$

CP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 18, 5:20 PM MST	Severe Thunderstorm Warning	VEF	Mohave	40 min
Jul 18, 5:40 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 18, 6:20 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	6 hr
Jul 19, 2:37 AM MST	Flash Flood Watch	VEF	Mohave	17 hr
Jul 19, 3:31 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.