Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 127, NWS Las Vegas, NV

August 31, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 31, 2021, 7:11 PM MST for Mohave County, Arizona. It was in force for 3 hr. 1 report 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 31, 2021, 7:11 PM MST (02:11 UTC)
Expired: Aug 31, 2021, 10:15 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), 60 km from the middle of the area, began a volume at 02:14 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 31, 7:50 PM MST	FLASH FLOOD	4 Sw Dolan Springs, AZ	DELAYED REPORT....PIERCE FERRY ROAD WAS DAMAGED BY FLOOD WATERS ALONG MULTIPLE SECTIONS OF ROADWAY BETWEEN US93 AND MILE MARKER 3. AREAS OF CURBSIDE WASHOUTS REQUIRED REPAIR AND A 3 FOOT DEEP HOLE NEEDED PATCHING. TIME ESTIMATED BY RADAR.

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 00:00Z, 2.2 hours before the alert went out and 150 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 0 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: -25 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.1

Open this sounding in Storm Lab

The text

As transmitted.

831 
WGUS55 KVEF 010211
FFWVEF
AZC015-010515-
/O.NEW.KVEF.FF.W.0127.210901T0211Z-210901T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
711 PM PDT Tue Aug 31 2021

The National Weather Service in Las Vegas has issued a

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

* Until 1015 PM MST.

* At 711 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. 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...
  Dolan Springs and Pierce Ferry Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 11427 3543 11428 3555 11437 3559 11437
      3559 11422 3547 11417

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

$$

JV

3 follow-up statements

186 
WGUS75 KVEF 010304 RRA
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
804 PM PDT Tue Aug 31 2021

AZC015-010515-
/O.CON.KVEF.FF.W.0127.000000T0000Z-210901T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
804 PM MST Tue Aug 31 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM MST THIS 
EVENING FOR WEST CENTRAL MOHAVE COUNTY...

At 804 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. 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...
  Dolan Springs and Pierce Ferry Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 11427 3543 11428 3555 11437 3559 11437
      3559 11422 3547 11417

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

$$

JV

012 
WGUS75 KVEF 010421
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
921 PM PDT Tue Aug 31 2021

AZC015-010515-
/O.CON.KVEF.FF.W.0127.000000T0000Z-210901T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
921 PM MST Tue Aug 31 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1015 PM MST THIS 
EVENING FOR WEST CENTRAL MOHAVE COUNTY...

At 921 PM MST, Doppler radar indicated thunderstorms were producing 
heavy rain across the warned area. Local officials confirm 4 to 5 
inches of water flowing over Pierce Ferry Road from mile marker 1 to 
5. Trucks in route to clear debris.

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...
  Dolan Springs and Pierce Ferry Road.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3541 11427 3543 11428 3555 11437 3559 11437
      3559 11422 3547 11417

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

$$

JV

849 
WGUS75 KVEF 010511
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1011 PM PDT Tue Aug 31 2021

AZC015-010521-
/O.EXP.KVEF.FF.W.0127.000000T0000Z-210901T0515Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
1011 PM MST Tue Aug 31 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 1015 PM MST THIS EVENING FOR 
WEST CENTRAL MOHAVE COUNTY...

The heavy rain has ended and flood waters over Pierce Ferry Road 
have receded. Flooding is no longer expected to pose a threat. 
Please continue to heed remaining road closures, if applicable.

A Flash Flood Watch remains in effect until 500 AM MST Thursday for 
portions of northwest Arizona, southeast California and southern 
Nevada.

LAT...LON 3541 11427 3543 11428 3555 11437 3559 11437
      3559 11422 3547 11417

$$

JV

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 31, 7:58 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 31, 9:38 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Sep 1, 1:08 AM MST	Areal Flood Advisory	VEF	Mohave	3 hr
Sep 1, 10:15 AM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	116 min

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.