Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 124, NWS Las Vegas, NV

August 30, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 30, 2021, 4:35 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
Aug 30, 2021, 4:35 PM MST (23:35 UTC)
Expired
Aug 30, 2021, 7:45 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), 61 km from the middle of the area, began a volume at 23:33 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, 11.6 hours before the alert went out and 114 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 2021-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 37 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 12:00Z on 2021-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
37 J/kg
Mixed-layer CIN
-324 J/kg
Mixed-layer LCL
3297 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

632 
WGUS55 KVEF 302335
FFWVEF
AZC015-310245-
/O.NEW.KVEF.FF.W.0124.210830T2335Z-210831T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
435 PM PDT Mon Aug 30 2021

The National Weather Service in Las Vegas has issued a

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

* Until 745 PM MST.

* At 435 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain south of Temple Bar Road. Water from these storms will 
  flow to Temple Bar Road, and flash flooding is 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...
  Temple Bar Campground and Temple Bar.

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.

&&

LAT...LON 3604 11437 3605 11437 3605 11430 3597 11429
      3598 11437

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

$$

CM
2 follow-up statements
739 
WGUS75 KVEF 310148
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
648 PM PDT Mon Aug 30 2021

AZC015-310245-
/O.CON.KVEF.FF.W.0124.000000T0000Z-210831T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
648 PM MST Mon Aug 30 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM MST THIS 
EVENING FOR NORTHWESTERN MOHAVE COUNTY...

At 648 PM MST, Heavy rain that fell earlier in the hills south of 
Temple Bar is expected to produce flash flooding along sections of 
Temple Bar road until at least 745 PM MST.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Radar.

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

Some locations that will experience flash flooding include...
  Temple Bar Road.

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.

&&

LAT...LON 3604 11437 3605 11437 3605 11430 3597 11429
      3598 11437

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

$$

JA
698 
WGUS75 KVEF 310241
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
741 PM PDT Mon Aug 30 2021

AZC015-310251-
/O.EXP.KVEF.FF.W.0124.000000T0000Z-210831T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
741 PM MST Mon Aug 30 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 745 PM MST THIS EVENING FOR 
NORTHWESTERN MOHAVE COUNTY...

Flood waters in washes around Temple Bar have likely receded. 
Flooding is no longer expected to pose a threat.

LAT...LON 3604 11437 3605 11437 3605 11430 3597 11429
      3598 11437

$$

JA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 5:42 PM MSTSevere Thunderstorm WarningVEFMohave48 min
Aug 30, 3:28 AM MSTFlash Flood WatchVEFMohave59 hr
Aug 30, 4:30 PM MSTFlash Flood Warning Considerable damage threatVEFMohave100 min

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.