Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 17, NWS Las Vegas, NV

July 17, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 17, 2021, 3:53 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, 3:53 PM MST (22:53 UTC)
Expired: Jul 17, 2021, 7:00 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), 129 km from the middle of the area, began a volume at 22:53 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, 10.9 hours before the alert went out and 204 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.

220 
WGUS55 KVEF 172253
FFWVEF
AZC015-180200-
/O.NEW.KVEF.FF.W.0017.210717T2253Z-210718T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
353 PM PDT Sat Jul 17 2021

The National Weather Service in Las Vegas has issued a

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

* Until 700 PM MST.

* At 353 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain east of Yucca, AZ along County Road 15. 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...
  mainly rural areas of South Central Mohave County

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3493 11407 3498 11402 3484 11392 3461 11366
      3454 11379 3473 11403 3485 11414 3486 11414

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

$$

CP

2 follow-up statements

057 
WGUS75 KVEF 180020
FFSVEF

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

AZC015-180200-
/O.CON.KVEF.FF.W.0017.000000T0000Z-210718T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
520 PM MST Sat Jul 17 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 7 PM MST THIS EVENING 
FOR SOUTH CENTRAL MOHAVE COUNTY...

At 520 PM MST, the thunderstorms that produced heavy rainfall have 
moved out of the area. However, radar indicated a large area saw 
over an inch of rainfall along higher terrain east of Yucca, AZ, 
leading to potential flash flooding along County Road 15 and other 
County roads east of Yucca. 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...
  mainly rural areas of South Central Mohave County near Yucca, AZ

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

In hilly terrain there are hundreds of low water crossings which are 
potentially dangerous in heavy rain. Do not attempt to cross flooded 
roads. Find an alternate route.

&&

LAT...LON 3493 11407 3498 11402 3484 11392 3461 11366
      3454 11379 3473 11403 3485 11414 3486 11414

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

$$

CP

328 
WGUS75 KVEF 180155
FFSVEF

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

AZC015-180205-
/O.EXP.KVEF.FF.W.0017.000000T0000Z-210718T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
655 PM MST Sat Jul 17 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 7 PM MST THIS EVENING FOR 
SOUTH 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 3493 11407 3498 11402 3484 11392 3461 11366
      3454 11379 3473 11403 3485 11414 3486 11414

$$

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, 2:08 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.