Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 16, NWS Las Vegas, NV

July 17, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 17, 2021, 2:08 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 17, 2021, 2:08 PM MST (21:08 UTC)
Expired: Jul 17, 2021, 5:15 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), 115 km from the middle of the area, began a volume at 21:11 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, 9.1 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 79 J/kg
Mixed-layer CIN: -104 J/kg
Mixed-layer LCL: 1452 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 146 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

870 
WGUS55 KVEF 172108
FFWVEF
AZC015-180015-
/O.NEW.KVEF.FF.W.0016.210717T2108Z-210718T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
208 PM PDT Sat Jul 17 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 515 PM MST.

* At 208 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain over the Flag Burn 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.

  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. Severe ash 
and 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 INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Morgan

2 follow-up statements

172 
WGUS75 KVEF 172211
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
311 PM PDT Sat Jul 17 2021

AZC015-180015-
/O.CON.KVEF.FF.W.0016.000000T0000Z-210718T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
311 PM MST Sat Jul 17 2021

...FLASH FLOOD WARNING FOR THE FLAG BURN AREA REMAINS IN EFFECT 
UNTIL 515 PM MST THIS AFTERNOON FOR SOUTHERN MOHAVE COUNTY...

At 311 PM MST, Doppler radar indicated that heavy rain had moved 
away from the Flag Burn Area. However, an inch of rain fell in only 
30 minutes, and debris flows were ongoing.

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

SOURCE...Radar.

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. Severe ash 
and 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 INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

Morgan

270 
WGUS75 KVEF 180010
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
510 PM PDT Sat Jul 17 2021

AZC015-180020-
/O.EXP.KVEF.FF.W.0016.000000T0000Z-210718T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
510 PM MST Sat Jul 17 2021

...FLASH FLOOD WARNING FOR THE FLAG BURN AREA WILL EXPIRE AT 515 PM 
MST THIS AFTERNOON 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

$$

CP

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 1:32 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	108 min
Jul 17, 3:53 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 17, 4:40 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr

Nearby

Flash Flood Warnings in Arizona, 2021 Every 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.