Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 33, NWS Las Vegas, NV

July 19, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 19, 2021, 5:07 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, 5:07 PM MST (00:07 UTC)
Expired
Jul 19, 2021, 8:15 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), 98 km from the middle of the area, began a volume at 00:04 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, 0.1 hours before the alert went out and 191 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-pSkew-T log-p diagram, Las Vegas, NV at 00:00Z on 2021-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 257 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 00:00Z on 2021-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 12 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
257 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
2423 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
12 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

408 
WGUS55 KVEF 200007
FFWVEF
AZC015-200315-
/O.NEW.KVEF.FF.W.0033.210720T0007Z-210720T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

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

* Until 815 PM MST.

* At 507 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across Warm Springs Wilderness and the Oatman Topock 
  Highway. 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...
  Bullhead City, Oatman, Mesquite Creek, Oatman Road, Oatman Topock 
  Highway and Mohave 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 3487 11429 3481 11428 3472 11447 3472 11449
      3473 11449 3477 11451 3485 11453 3490 11455
      3495 11457 3500 11458 3508 11458 3515 11438
      3514 11438

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

$$

CP
2 follow-up statements
148 
WGUS75 KVEF 200059
FFSVEF

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

AZC015-200315-
/O.CON.KVEF.FF.W.0033.000000T0000Z-210720T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
559 PM MST Mon Jul 19 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM MST THIS 
EVENING FOR SOUTHWESTERN MOHAVE COUNTY...

At 559 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the Black Mountains west and along the Oatman Topock 
Highway. Between 1 and 1.5 inches of rain have fallen. 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...
  Bullhead City, Oatman, Mesquite Creek and Mohave 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 3487 11429 3481 11428 3472 11447 3472 11449
      3473 11449 3477 11451 3485 11453 3490 11455
      3495 11457 3500 11458 3508 11458 3515 11438
      3514 11438

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

$$

CP
001 
WGUS75 KVEF 200308
FFSVEF

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

AZC015-200318-
/O.EXP.KVEF.FF.W.0033.000000T0000Z-210720T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
808 PM MST Mon Jul 19 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 815 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.

LAT...LON 3487 11429 3481 11428 3472 11447 3472 11449
      3473 11449 3477 11451 3485 11453 3490 11455
      3495 11457 3500 11458 3508 11458 3515 11438
      3514 11438

$$

CP

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 3:13 PM MSTFlash Flood Warning Considerable damage threatVEFMohave3 hr
Jul 20, 3:28 PM MSTFlash Flood Warning Considerable damage threatVEFMohave3 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.