Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 101, NWS Las Vegas, NV

August 10, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 10, 2021, 2:13 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 10, 2021, 2:13 PM MST (21:13 UTC)
Expired: Aug 10, 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), 93 km from the middle of the area, began a volume at 21:13 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, 9.2 hours before the alert went out and 174 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: 6 J/kg
Mixed-layer CIN: -327 J/kg
Mixed-layer LCL: 3246 m above ground
0-6 km bulk shear: 7 kt
0-1 km storm-relative helicity: -14 m²/s²
0-3 km storm-relative helicity: 22 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

469 
WGUS55 KVEF 102113
FFWVEF
AZC015-110015-
/O.NEW.KVEF.FF.W.0101.210810T2113Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
213 PM PDT Tue Aug 10 2021

The National Weather Service in Las Vegas has issued a

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

* Until 515 PM MST.

* At 213 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in Antares Road. 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...
  Antares Road in Central Mohave County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3549 11377 3541 11397 3559 11409 3565 11398
      3571 11384 3561 11375

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

$$

SC

2 follow-up statements

913 
WGUS75 KVEF 102246
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
346 PM PDT Tue Aug 10 2021

AZC015-110015-
/O.CON.KVEF.FF.W.0101.000000T0000Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
346 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM MST THIS 
AFTERNOON FOR CENTRAL MOHAVE COUNTY...

At 346 PM MST, Doppler radar indicated thunderstorms have diminished 
along Antares Road but rainfall estimated rainfall was between 1.5 
and 2.0 inches. Runoff from the earlier storms is likely continuing 
to produce flash flooding.

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...
  Antares Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3549 11377 3541 11397 3559 11409 3565 11398
      3571 11384 3561 11375

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

$$

SC

529 
WGUS75 KVEF 110014
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
514 PM PDT Tue Aug 10 2021

AZC015-110024-
/O.EXP.KVEF.FF.W.0101.000000T0000Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
514 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM MST THIS AFTERNOON FOR 
CENTRAL 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 3549 11377 3541 11397 3559 11409 3565 11398
      3571 11384 3561 11375

$$

SC

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 10, 12:30 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 10, 1:22 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	2 hr
Aug 10, 1:35 PM MST	Severe Thunderstorm Warning	VEF	Mohave	40 min
Aug 10, 2:05 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 10, 2:06 PM MST	Dust Storm Warning	VEF	Mohave	54 min
Aug 10, 2:50 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 10, 3:25 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 10, 3:51 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 10, 4:59 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.