Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 61, NWS Las Vegas, NV

July 25, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 25, 2021, 4:21 PM MST for Mohave County, Arizona. It was in force for 2 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 25, 2021, 4:21 PM MST (23:21 UTC)
Expired: Jul 25, 2021, 6:23 PM MST
In force: 2 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 23:25 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, 11.4 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: 4 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 803 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

870 
WGUS55 KVEF 252321
FFWVEF
AZC015-260230-
/O.NEW.KVEF.FF.W.0061.210725T2321Z-210726T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
421 PM PDT Sun Jul 25 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 730 PM MST.

* At 421 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain heading towards the Flag Burn Area in the next hour. 
  The expected rainfall rate is 1 to 2 inches per hour. Flash 
  flooding expected to begin in the next hour.

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

  SOURCE...Radar and upstream rain 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 the community of 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. 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
EXPECTED RAINFALL...1-2 INCHES IN 1 HOUR

$$

TB

1 follow-up statement

119 
WGUS75 KVEF 260123
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
623 PM PDT Sun Jul 25 2021

AZC015-260133-
/O.CAN.KVEF.FF.W.0061.000000T0000Z-210726T0230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
623 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING FOR THE FLAG BURN AREA IS CANCELLED FOR 
SOUTHERN MOHAVE COUNTY...

The heavy rain missed the burn scar to the north and only light to 
moderate rainfall occurred. Flooding is no longer expected to pose a 
threat.

A Flash Flood Watch remains in effect until 1200 AM MST for portions 
of northwest Arizona, southeast California and southern Nevada.

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

$$

TB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 2:53 PM MST	Severe Thunderstorm Warning	VEF	Mohave	67 min
Jul 25, 3:44 PM MST	Areal Flood Advisory	VEF	Mohave	3 hr
Jul 25, 3:59 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	2 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.