Alert archive / Arizona / Flash Flood Warnings in 2021

Flash Flood Warning 27, NWS Las Vegas, NV

July 18, 2021Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 18, 2021, 5:40 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
Jul 18, 2021, 5:40 PM MST (00:40 UTC)
Expired
Jul 18, 2021, 8:45 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), 71 km from the middle of the area, began a volume at 00:41 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

TimeReportWhereRemark
Jul 18, 6:15 PM MSTFLASH FLOOD2 Ne Meadview, AZSPOTTER IN MEADVIEW REPORTED THAT WATER WASHED OUT SPENCER DRIVE AND LEFT QUITE A BIT OF MUD OVER THE ROAD. ALSO REPORTED THAT THE WASH HAD CROSSED OVER PIERCE FERRY ROAD YESTERDAY.

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, 0.7 hours before the alert went out and 136 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-pSkew-T log-p diagram, Las Vegas, NV at 00:00Z on 2021-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 470 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Las Vegas, NV at 00:00Z on 2021-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -43 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
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
470 J/kg
Mixed-layer CIN
-221 J/kg
Mixed-layer LCL
2357 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-43 m²/s²
0-3 km storm-relative helicity
-38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

052 
WGUS55 KVEF 190040
FFWVEF
AZC015-190345-
/O.NEW.KVEF.FF.W.0027.210719T0040Z-210719T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
540 PM PDT Sun Jul 18 2021

The National Weather Service in Las Vegas has issued a

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

* Until 845 PM MST.

* At 540 PM MST, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. Flash flooding is ongoing or 
  expected to begin shortly in Meadview impacting Pierce Ferry Road.

  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, Grand Canyon Ranch, Meadview and 
  Dolan Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3598 11423 3608 11401 3584 11392 3567 11419
      3584 11431

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

$$

JV
2 follow-up statements
190 
WGUS75 KVEF 190137
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
637 PM PDT Sun Jul 18 2021

AZC015-190345-
/O.CON.KVEF.FF.W.0027.000000T0000Z-210719T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
637 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM MST THIS 
EVENING FOR WEST CENTRAL MOHAVE COUNTY...

At 637 PM MST, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Flash flooding is ongoing or expected 
to begin shortly in Meadview impacting Pierce Ferry Road. Meadview 
sensor has measured over an inch of rainfall, and rain continues to 
fall.

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, Grand Canyon Ranch, Meadview and 
  Dolan Springs.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3598 11423 3608 11401 3584 11392 3567 11419
      3584 11431

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

$$

JV
050 
WGUS75 KVEF 190339
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
839 PM PDT Sun Jul 18 2021

AZC015-190349-
/O.EXP.KVEF.FF.W.0027.000000T0000Z-210719T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Mohave AZ-
839 PM MST Sun Jul 18 2021

...FLASH FLOOD WARNING WILL EXPIRE AT 845 PM MST THIS EVENING FOR 
WEST CENTRAL MOHAVE COUNTY...

Flood waters have receded. Isolated moderate rainfall, nuisance 
flooding and roadway ponding expected to continue over the next 
hour. Heed all road closures, if applicable.

LAT...LON 3598 11423 3608 11401 3584 11392 3567 11419
      3584 11431

$$

JV

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 5:20 PM MSTSevere Thunderstorm WarningVEFMohave40 min
Jul 18, 6:20 PM MSTFlash Flood Warning Considerable damage threatVEFMohave6 hr
Jul 19, 2:37 AM MSTFlash Flood WatchVEFMohave17 hr
Jul 19, 2:31 PM MSTFlash Flood Warning Considerable damage threatVEFMohave3 hr
Jul 19, 3:31 PM MSTFlash Flood Warning Considerable damage threatVEFMohave3 hr

Nearby

Flash Flood Warnings in Arizona, 2021Every 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.