Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 55, NWS Las Vegas, NV

July 23, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 23, 2021, 4:39 PM MST for Mohave County, Arizona. It was in force for 81 min. 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 23, 2021, 4:39 PM MST (23:39 UTC)
Expired
Jul 23, 2021, 6:00 PM MST
In force
81 min
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), 133 km from the middle of the area, began a volume at 23:40 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, 11.7 hours before the alert went out and 160 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, Flgstf/Belemont, AZ at 12:00Z on 2021-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 503 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 12:00Z on 2021-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 square meters per square second.1939Sfc1 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
503 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
915 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

621 
WGUS55 KVEF 232339
FFWVEF
AZC015-240100-
/O.NEW.KVEF.FF.W.0055.210723T2339Z-210724T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
439 PM PDT Fri Jul 23 2021

The National Weather Service in Las Vegas has issued a

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

* Until 600 PM MST.

* At 439 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.75 and 1.5 inches of 
  rain have likely fallen resulting in runoff possibly affecting 
  parts of Interstate 40. 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...
  mainly rural areas of Central Mohave County but including the 
  Interstate 40 corridor east of US 93 interchange.

This includes the following highways...
	Interstate 40 in Arizona between mile markers 74 and 88.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3526 11366 3531 11352 3530 11339 3519 11340
      3512 11352 3508 11365 3514 11366

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

$$

TB
2 follow-up statements
061 
WGUS75 KVEF 240026
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
526 PM PDT Fri Jul 23 2021

AZC015-240100-
/O.CON.KVEF.FF.W.0055.000000T0000Z-210724T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
526 PM MST Fri Jul 23 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 6 PM MST THIS EVENING 
FOR CENTRAL MOHAVE COUNTY...

At 526 PM MST, Public reports of flooding on Interstate 40 were 
received in the last hour. Between 1 and 2 inches of rain have 
fallen in this area and flash flooding is likely ongoing.

HAZARD...Life-threatening flash flooding.

SOURCE...Public reported.

IMPACT...Life-threatening flash flooding of low-water crossings
         along Interstate 40, creeks, normally dry washes and
         roads.

Some locations that will experience flash flooding include...
  mainly rural areas of Central Mohave County along the Interstate 
  40 corridor.

This includes the following highways...
	Interstate 40 in Arizona between mile markers 74 and 89.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3526 11366 3531 11352 3530 11339 3519 11340
      3512 11352 3508 11365 3514 11366

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

TB
353 
WGUS75 KVEF 240056
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
556 PM PDT Fri Jul 23 2021

AZC015-240106-
/O.EXP.KVEF.FF.W.0055.000000T0000Z-210724T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
556 PM MST Fri Jul 23 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM MST THIS EVENING FOR 
CENTRAL MOHAVE COUNTY...

Flood waters have receded and the heavy rain has ended. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures and avoid driving through flooded roadways.

LAT...LON 3526 11366 3531 11352 3530 11339 3519 11340
      3512 11352 3508 11365 3514 11366

$$

TB

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 23, 1:11 PM MSTFlash Flood WatchVEFMohave3 days

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.