Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 60, NWS Las Vegas, NV

July 25, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 25, 2021, 3:59 PM MST for Mohave County, Arizona. It was in force for 2 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: Jul 25, 2021, 3:59 PM MST (22:59 UTC)
Expired: Jul 25, 2021, 6:00 PM MST
In force: 2 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), 135 km from the middle of the area, began a volume at 22:59 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
Jul 25, 5:00 PM MST	FLASH FLOOD	12 S Valentine, AZ	SOUTH HACKBERRY ROAD FROM US 93 TO EAST AUSTIN PEAK CLOSED DUE TO FLOODING. LOCATION AND TIME WERE ESTIMATED USING RADAR GAUGES AND MAPS.
Jul 25, 5:32 PM MST	FLASH FLOOD	15 Ene Hualapai Peak, AZ	EAST KNIGHT CREEK FROM SOUTH HACKBERRY ROAD TO MILEPOST 4.6 CLOSED DUE TO FLOODING. LOCATION AND TIME WERE ESTIMATED USING RADAR GAUGES AND MAPS.

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 12:00Z, 11.0 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: 4 J/kg
Mixed-layer CIN: -19 J/kg
Mixed-layer LCL: 803 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -30 m²/s²
0-3 km storm-relative helicity: 25 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

284 
WGUS55 KVEF 252259
FFWVEF
AZC015-260100-
/O.NEW.KVEF.FF.W.0060.210725T2259Z-210726T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
359 PM PDT Sun Jul 25 2021

The National Weather Service in Las Vegas has issued a

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

* Until 600 PM MST.

* At 359 PM MST, Doppler radar and automated rain gauges indicated 
  thunderstorms producing heavy rain across the warned area. Between 
  1 and 1.5 inches of rain have fallen with rain rates over 3 inches 
  per hour. Flash flooding is ongoing or expected to begin shortly.

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

  SOURCE...Radar and automated gauges.

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

* Some locations that will experience flash flooding include...
  Valentine, Diamond M Ranch, Diamond Creek Campground and Peach 
  Springs.

Flooding is likely also to effect Interstate 40 east of the Highway 
93 interchange. Do not attempt to drive through flooded roadways!

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Be aware of your surroundings and do not drive on flooded roads.

Please report observed flooding to local emergency services or law 
enforcement and request they pass this information to the National 
Weather Service when you can do so safely.

&&

LAT...LON 3483 11333 3484 11374 3547 11380 3598 11332
      3596 11332 3595 11333 3592 11333 3589 11331
      3586 11331 3584 11333 3580 11333

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

$$

TB

1 follow-up statement

966 
WGUS75 KVEF 260053
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
553 PM PDT Sun Jul 25 2021

AZC015-260103-
/O.EXP.KVEF.FF.W.0060.000000T0000Z-210726T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
553 PM MST Sun Jul 25 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 6 PM MST THIS EVENING FOR 
CENTRAL MOHAVE COUNTY...

Flood waters have receded and the heavy rain has ended. Flooding is 
no longer expected to pose a threat. Please continue to heed 
remaining road closures.

A Flash Flood Watch remains in effect until 1200 AM MST Monday for 
portions of northwest Arizona, southeast California and southern 
Nevada.

LAT...LON 3483 11333 3484 11374 3547 11380 3598 11332
      3596 11332 3595 11333 3592 11333 3589 11331
      3586 11331 3584 11333 3580 11333

$$

TB

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 2:53 PM MST	Severe Thunderstorm Warning	VEF	Mohave	67 min
Jul 25, 3:44 PM MST	Areal Flood Advisory	VEF	Mohave	3 hr
Jul 25, 4:21 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.