Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 100, NWS Las Vegas, NV

August 10, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 10, 2021, 2:05 PM MST for Mohave County, Arizona. It was in force for 3 hr. 2 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Aug 10, 2021, 2:05 PM MST (21:05 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), 66 km from the middle of the area, began a volume at 21:04 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.

What was reported inside it

Time	Report	Where	Remark
Aug 10, 2:42 PM MST	FLASH FLOOD	15 Nne Dolan Springs, AZ	PIERCE FERRY ROAD IS CLOSED BETWEEN MP 13 AND ANTARES RD DUE TO HIGH WATER.
Aug 10, 2:56 PM MST	FLASH FLOOD	15 Ne Dolan Springs, AZ	ANTARES RD IS CLOSED BETWEEN HWY 66 AND PIERCE FERRY ROAD DUE TO HIGH WATER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 9.1 hours before the alert went out and 139 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.

941 
WGUS55 KVEF 102105
FFWVEF
AZC015-110015-
/O.NEW.KVEF.FF.W.0100.210810T2105Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

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

* Until 515 PM MST.

* At 205 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain in Pierce Ferry Road, Diamond Bar Road and Lucky 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...
  Pierce Ferry And Antares Roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3578 11421 3594 11420 3594 11403 3570 11407
      3571 11422 3575 11422

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

$$

SC

2 follow-up statements

868 
WGUS75 KVEF 102143
FFSVEF

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

AZC015-110015-
/O.CON.KVEF.FF.W.0100.000000T0000Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
243 PM MST Tue Aug 10 2021

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

At 243 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain in Pierce Ferry Road, Diamond Bar Road and Stockton Hill Road. 
Flash flooding is ongoing or expected to begin shortly.

HAZARD...Life-threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...The Aileron Orchards rain gauge at the intersection of
         Pierce Ferry Road and Stockton Hill Roads has received
         more than 1.5 inches of rain since 145 MST.

IMPACT...Life-threatening flash flooding of low-water crossings,
         creeks, normally dry washes and roads.

Some locations that will experience flash flooding include...
  Pierce Ferry and Stockton Hill Roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3578 11421 3594 11420 3594 11403 3570 11407
      3571 11422 3575 11422

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

$$

SC

581 
WGUS75 KVEF 110013
FFSVEF

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

AZC015-110023-
/O.EXP.KVEF.FF.W.0100.000000T0000Z-210811T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
513 PM MST Tue Aug 10 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 515 PM MST THIS AFTERNOON FOR 
NORTHWESTERN 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 3578 11421 3594 11420 3594 11403 3570 11407
      3571 11422 3575 11422

$$

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, 2:06 PM MST	Dust Storm Warning	VEF	Mohave	54 min
Aug 10, 2:13 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.