Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 21, NWS Las Vegas, NV

July 18, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 18, 2021, 3:14 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 18, 2021, 3:14 PM MST (22:14 UTC)
Expired: Jul 18, 2021, 6:15 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), 111 km from the middle of the area, began a volume at 22:15 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, 10.2 hours before the alert went out and 176 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: 191 J/kg
Mixed-layer CIN: -101 J/kg
Mixed-layer LCL: 1511 m above ground
0-6 km bulk shear: 16 kt
0-1 km storm-relative helicity: 14 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

285 
WGUS55 KVEF 182214
FFWVEF
AZC015-190115-
/O.NEW.KVEF.FF.W.0021.210718T2214Z-210719T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
314 PM PDT Sun Jul 18 2021

The National Weather Service in Las Vegas has issued a

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

* Until 615 PM MST.

* At 314 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly, particularly over Hackberry Road 
  between Historic Route 66 and Interstate 40 as well as Antares 
  Road north of Historic Route 66. Road ponding possible along 66 
  through Valentine.

  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...
  Valentine.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3558 11392 3559 11381 3523 11351 3517 11355
      3517 11365

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

$$

JV

2 follow-up statements

888 
WGUS75 KVEF 182315
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
415 PM PDT Sun Jul 18 2021

AZC015-190115-
/O.CON.KVEF.FF.W.0021.000000T0000Z-210719T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
415 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 615 PM MST THIS 
EVENING FOR CENTRAL MOHAVE COUNTY...

At 415 PM MST, Doppler radar indicated thunderstorms produced heavy 
rain across the warned area. Though heavy rain has largely ceased, 
thunderstorm activity in and around the area is expected to continue 
through the afternoon, with the flash flood threat persisting along 
Antares Road and Hackberry Road.

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...
  Valentine.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3558 11392 3559 11381 3523 11351 3517 11355
      3517 11365

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

$$

JV

210 
WGUS75 KVEF 190110
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
610 PM PDT Sun Jul 18 2021

AZC015-190120-
/O.EXP.KVEF.FF.W.0021.000000T0000Z-210719T0115Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
610 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 615 PM MST THIS EVENING FOR 
CENTRAL MOHAVE COUNTY...

Thunderstorms have moved out of the area. Flooding is no longer 
expected to pose a threat. Please continue to heed remaining road 
closures, if applicable.

LAT...LON 3558 11392 3559 11381 3523 11351 3517 11355
      3517 11365

$$

JV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 17, 5:33 PM MST	Severe Thunderstorm Warning	VEF	Mohave	57 min
Jul 18, 1:33 PM MST	Areal Flood Advisory	VEF	Mohave	80 min
Jul 18, 2:51 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Jul 18, 3:07 PM MST	Severe Thunderstorm Warning	VEF	Mohave	23 min
Jul 18, 3:46 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.