Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 116, NWS Las Vegas, NV

August 29, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 29, 2021, 3:43 PM MST for Mohave County, Arizona. It was in force for 3 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Aug 29, 2021, 3:43 PM MST (22:43 UTC)
Expired
Aug 29, 2021, 6:45 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), 115 km from the middle of the area, began a volume at 22:45 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.

What was reported inside it

TimeReportWhereRemark
Aug 29, 4:18 PM MSTFLASH FLOOD2 Ne Hualapai Peak, AZEMERGENCY MANAGERS REPORTED DANGEROUS FLOODING OVER FLAG MINE ROAD AT HUALAPAI MOUNTAIN PARK. THE ROAD IS CLOSED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 12:00Z, 10.7 hours before the alert went out and 188 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 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 21 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 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 1 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
21 J/kg
Mixed-layer CIN
-175 J/kg
Mixed-layer LCL
2328 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
1 m²/s²
0-3 km storm-relative helicity
85 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

494 
WGUS55 KVEF 292243
FFWVEF
AZC015-300145-
/O.NEW.KVEF.FF.W.0116.210829T2243Z-210830T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
343 PM PDT Sun Aug 29 2021

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  The Flag Burn Area in...
  Southern Mohave County in northwestern Arizona...

* Until 645 PM MST.

* At 343 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain over the Flag Burn Area. 
  Between 0.5 and 0.75 inches of rain have fallen. Additional 
  rainfall amounts of 0.5 to 0.75 inches are possible in the warned 
  area. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Flag Burn
           Area.

  SOURCE...Radar and automated gauges.

  IMPACT...Life-threatening flash flooding of areas in and around
           the Flag Burn Area.

* Some locations that will experience flash flooding include...
  Hualapai Mountain Park.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of Wheeler Wash and other washes 
in and around Pine Lake and the Hualapai Mountain Park. Debris flows 
can occur well downstream of the burn area which could potentially 
impact area roads. Watch for falling rocks. If you encounter flood 
waters...climb to safety.

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

&&

LAT...LON 3509 11383 3509 11381 3508 11384 3508 11385
      3508 11386 3508 11387 3507 11388 3508 11390
      3509 11391 3509 11390 3510 11389 3510 11388
      3509 11387 3509 11386 3509 11385

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

$$

BKP
3 follow-up statements
047 
WGUS55 KVEF 292249 CCA
FFWVEF
AZC015-300145-
/O.COR.KVEF.FF.W.0116.210829T2243Z-210830T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning...CORRECTED
National Weather Service Las Vegas NV
349 PM PDT Sun Aug 29 2021

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  The Flag Burn Area in...
  Southern Mohave County in northwestern Arizona...

* Until 645 PM MST.

* At 343 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain over the Flag Burn Area. 
  Between 0.5 and 0.75 inches of rain have fallen. Additional 
  rainfall amounts of 0.5 to 0.75 inches are possible in the warned 
  area. Flash flooding is ongoing or expected to begin shortly.

  HAZARD...Life-threatening flash flooding. Thunderstorms
           producing flash flooding in and around the Flag Burn
           Area.

  SOURCE...Radar and automated gauges.

  IMPACT...Life-threatening flash flooding of areas in and around
           the Flag Burn Area.

* Some locations that will experience flash flooding include...
  Hualapai Mountain Park and Pine Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of Wheeler Wash and other washes 
in and around Pine Lake and the Hualapai Mountain Park. Debris flows 
can occur well downstream of the burn area which could potentially 
impact area roads. Watch for falling rocks. If you encounter flood 
waters...climb to safety.

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

&&

LAT...LON 3509 11383 3509 11381 3508 11384 3508 11385
      3508 11386 3508 11387 3507 11388 3508 11390
      3509 11391 3509 11390 3510 11389 3510 11388
      3509 11387 3509 11386 3509 11385

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

$$

BKP
946 
WGUS75 KVEF 292342
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
442 PM PDT Sun Aug 29 2021

AZC015-300145-
/O.CON.KVEF.FF.W.0116.000000T0000Z-210830T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
442 PM MST Sun Aug 29 2021

...FLASH FLOOD WARNING FOR THE FLAG BURN AREA REMAINS IN EFFECT 
UNTIL 645 PM MST THIS EVENING FOR SOUTHERN MOHAVE COUNTY...

At 442 PM MST, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain over the Flag Burn Area have 
weakened. Mohave County Flood Control gages observed up to 1.30 
inches on the burn scar. Flooding of washes and roads is still 
occurring.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding in and around the Flag Burn Area.

SOURCE...Radar and automated gauges.

IMPACT...Life-threatening flash flooding of areas in and around
         the Flag Burn Area.

Some locations that will experience flash flooding include...
  Hualapai Mountain Park and Pine Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a life-threatening situation. Heavy rainfall will cause 
extensive and severe flash flooding of Wheeler Wash and other washes 
in and around Pine Lake and the Hualapai Mountain Park. Debris flows 
can occur well downstream of the burn area which could potentially 
impact area roads. Watch for falling rocks. If you encounter flood 
waters...climb to safety.

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

&&

LAT...LON 3509 11383 3509 11381 3508 11384 3508 11385
      3508 11386 3508 11387 3507 11388 3508 11390
      3509 11391 3509 11390 3510 11389 3510 11388
      3509 11387 3509 11386 3509 11385

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

$$

BKP
746 
WGUS75 KVEF 300141
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
641 PM PDT Sun Aug 29 2021

AZC015-300151-
/O.EXP.KVEF.FF.W.0116.000000T0000Z-210830T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
641 PM MST Sun Aug 29 2021

...FLASH FLOOD WARNING FOR THE FLAG BURN AREA WILL EXPIRE AT 645 PM 
MST THIS EVENING FOR SOUTHERN 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 3509 11383 3509 11381 3508 11384 3508 11385
      3508 11386 3508 11387 3507 11388 3508 11390
      3509 11391 3509 11390 3510 11389 3510 11388
      3509 11387 3509 11386 3509 11385

$$

BKP

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 29, 3:15 PM MSTSevere Thunderstorm WarningVEFMohave32 min
Aug 29, 4:18 PM MSTFlash Flood Warning Considerable damage threatVEFMohave117 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.