Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 78, NWS Las Vegas, NV

July 26, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 26, 2021, 1:51 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 26, 2021, 1:51 PM MST (20:51 UTC)
Expired
Jul 26, 2021, 5:00 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 Cedar City radar (KICX), 122 km from the middle of the area, began a volume at 20:54 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, 8.9 hours before the alert went out and 156 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 12:00Z on 2021-07-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 467 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 12:00Z on 2021-07-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
467 J/kg
Mixed-layer CIN
-144 J/kg
Mixed-layer LCL
1095 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

As transmitted.

937 
WGUS55 KVEF 262051
FFWVEF
AZC015-270000-
/O.NEW.KVEF.FF.W.0078.210726T2051Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
151 PM PDT Mon Jul 26 2021

The National Weather Service in Las Vegas has issued a

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

* Until 500 PM MST.

* At 151 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the Arizona Strip. A rain gauge at Scenic 
  measured near 1 inch of rain in 30 minutes.  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...
  Littlefield, Virgin River Gorge, Beaver Dam and Virgin River 
  Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11360 3689 11358 3681 11365 3667 11403
      3671 11405 3675 11405 3684 11405 3688 11405
      3690 11405 3696 11405 3700 11405 3700 11402
      3700 11397

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

$$

CO
2 follow-up statements
642 
WGUS75 KVEF 262155
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
255 PM PDT Mon Jul 26 2021

AZC015-270000-
/O.CON.KVEF.FF.W.0078.000000T0000Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
255 PM MST Mon Jul 26 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 5 PM MST THIS 
AFTERNOON FOR NORTH CENTRAL MOHAVE COUNTY...

At 255 PM MST, Heavy rain has begun to diminish across the Arizona 
strip but elevated stream flows and areas of flash flooding remain 
possible as runoff continues. Continue to heed any road closures.

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...
  Littlefield, Virgin River Gorge, Beaver Dam and Virgin River 
  Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11360 3689 11358 3681 11365 3667 11403
      3671 11405 3675 11405 3684 11405 3688 11405
      3690 11405 3696 11405 3700 11405 3700 11402
      3700 11397

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

$$

CO
629 
WGUS75 KVEF 262357
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
457 PM PDT Mon Jul 26 2021

AZC015-270007-
/O.EXP.KVEF.FF.W.0078.000000T0000Z-210727T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
457 PM MST Mon Jul 26 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 5 PM MST THIS AFTERNOON FOR 
NORTH CENTRAL 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 3700 11360 3689 11358 3681 11365 3667 11403
      3671 11405 3675 11405 3684 11405 3688 11405
      3690 11405 3696 11405 3700 11405 3700 11402
      3700 11397

$$

BKP

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 25, 5:04 PM MSTFlash Flood Warning Considerable damage threatVEFMohave5 hr
Jul 25, 5:06 PM MSTSevere Thunderstorm WarningVEFMohave54 min
Jul 25, 5:12 PM MSTDust Storm WarningVEFMohave63 min
Jul 25, 5:37 PM MSTFlash Flood Warning Considerable damage threatVEFMohave3 hr
Jul 25, 6:01 PM MSTSevere Thunderstorm WarningVEFMohave59 min
Jul 25, 7:08 PM MSTSevere Thunderstorm WarningVEFMohave52 min
Jul 25, 7:57 PM MSTSevere Thunderstorm WarningVEFMohave63 min
Jul 25, 8:59 PM MSTSevere Thunderstorm WarningVEFMohave61 min
Jul 25, 10:26 PM MSTAreal Flood WarningVEFMohave8 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.