Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 109, NWS Las Vegas, NV

August 12, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 12, 2021, 5:24 PM MST for Mohave County, Arizona. It was in force for 111 min. 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 12, 2021, 5:24 PM MST (00:24 UTC)
Expired: Aug 12, 2021, 7:15 PM MST
In force: 111 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Damage threat: Considerable
Flood severity: None

County Mohave County, AZ

The radar

The Cedar City radar (KICX), 68 km from the middle of the area, began a volume at 00:25 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 12, 5:35 PM MST	FLASH FLOOD	Colorado City, AZ	RICHARD STREET WAS CLOSED FOR FIVE TO TEN MINUTES DUE TO WATER FROM SHORT CREEK RUNNING OVER THE ROAD AS STORMS MOVED THROUGH THE AREA.

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

The nearest sounding before it

Flgstf/Belemont, AZ (KFGZ), launched 00:00Z, 0.4 hours before the alert went out and 223 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: 2 J/kg
Mixed-layer CIN: -99 J/kg
Mixed-layer LCL: 1844 m above ground
0-6 km bulk shear: 5 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.

813 
WGUS55 KVEF 130024
FFWVEF
AZC015-130330-
/O.NEW.KVEF.FF.W.0109.210813T0024Z-210813T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
524 PM PDT Thu Aug 12 2021

The National Weather Service in Las Vegas has issued a

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

* Until 830 PM MST.

* At 524 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Between 0.5 and 0.75 inches of 
  rain have fallen around the short creek watershed. 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...
  Colorado City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11293 3692 11298 3700 11309 3700 11300
      3700 11299

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

$$

CO

2 follow-up statements

672 
WGUS75 KVEF 130122
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
622 PM PDT Thu Aug 12 2021

AZC015-130330-
/O.CON.KVEF.FF.W.0109.000000T0000Z-210813T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
622 PM MST Thu Aug 12 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 830 PM MST THIS 
EVENING FOR NORTHERN MOHAVE COUNTY...

At 622 PM MST, Heavy rainfall in Colorado City and the Hildale area 
has ended, but areas of excessive runoff continue. Continue to heed 
any local road closures.

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...
  Colorado City.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3700 11293 3692 11298 3700 11309 3700 11300
      3700 11299

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

$$

CO

482 
WGUS75 KVEF 130215
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
715 PM PDT Thu Aug 12 2021

AZC015-130225-
/O.CAN.KVEF.FF.W.0109.000000T0000Z-210813T0330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
715 PM MST Thu Aug 12 2021

...FLASH FLOOD WARNING IS CANCELLED FOR NORTHERN MOHAVE COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining road closures.

LAT...LON 3700 11293 3692 11298 3700 11309 3700 11300
      3700 11299

$$

CO

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 12, 5:43 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 8:17 PM MST	Severe Thunderstorm Warning	VEF	Mohave	58 min
Aug 12, 8:42 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 8:54 PM MST	Flash Flood Warning Considerable damage threat	VEF	Mohave	3 hr
Aug 12, 9:10 PM MST	Severe Thunderstorm Warning	VEF	Mohave	50 min
Aug 12, 10:56 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.