Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 135, NWS Las Vegas, NV

August 20, 2012Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 20, 2012, 6:09 PM MST for Mohave County, Arizona. It was in force for 2 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 20, 2012, 6:09 PM MST (01:09 UTC)
Expired
Aug 20, 2012, 8:10 PM MST
In force
2 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Mohave County, AZ

The radar

The Las Vegas radar (KESX), 154 km from the middle of the area, began a volume at 01:10 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
Aug 20, 6:15 PM MSTHEAVY RAIN 1.427 Wsw Wikieup, AZA MOHAVE COUNTY ALERT GAUGE LOCATED ON TOP OF AUBREY PEAK MEASURED A 30 MINUTE RAINFALL TOTAL OF 1.42 INCHES.

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, 1.2 hours before the alert went out and 185 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, Flgstf/Belemont, AZ at 00:00Z on 2012-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 217 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Flgstf/Belemont, AZ at 00:00Z on 2012-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 square meters per square second.1939Sfc1 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
217 J/kg
Mixed-layer CIN
-45 J/kg
Mixed-layer LCL
1521 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-9 m²/s²
0-3 km storm-relative helicity
19 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

651 
WGUS55 KVEF 210109
FFWVEF
AZC015-210315-
/O.NEW.KVEF.FF.W.0135.120821T0109Z-120821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
609 PM MST MON AUG 20 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL MOHAVE COUNTY IN NORTHWEST ARIZONA...

* UNTIL 815 PM MST.

* AT 559 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 7 MILES SOUTHWEST OF WIKIEUP.
  THE STORM PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  WIKIEUP.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO CROSS A FLOODED
ROADWAY OR WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

REPORT FLOODING BY POSTING YOUR REPORT TO THE LAS VEGAS NATIONAL
WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER HASHTAG...
NWSVEGAS.

&&

LAT...LON 3477 11383 3479 11361 3459 11353 3456 11380

$$

ASG
2 follow-up statements
530 
WGUS75 KVEF 210153
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
653 PM MST MON AUG 20 2012

AZC015-210315-
/O.CON.KVEF.FF.W.0135.000000T0000Z-120821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
653 PM MST MON AUG 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 815 PM MST FOR SOUTH
CENTRAL MOHAVE COUNTY...

AT 644 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING VERY HEAVY RAIN...MAINLY WEST OF 
WIKIEUP OVER THE HUALAPAI MOUNTAINS. RUNOFF FROM THIS STORM IS 
LIKELY TO AFFECT CHICKEN SPRINGS ROAD WHICH LEADS INTO WIKIEUP.   
THE THUNDERSTORM WITH EXCESSIVE RAIN WAS MOVING SLOWLY WEST. 

LOCATIONS IMPACTED INCLUDE...
WIKIEUP...CHICKEN SPRINGS ROAD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO CROSS A FLOODED
ROADWAY OR WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

REPORT FLOODING BY POSTING YOUR REPORT TO THE LAS VEGAS NATIONAL
WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER HASHTAG...
NWSVEGAS.

&&

LAT...LON 3477 11383 3479 11361 3459 11353 3456 11380

$$

ASG
139 
WGUS75 KVEF 210310
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
810 PM MST MON AUG 20 2012

AZC015-210315-
/O.CAN.KVEF.FF.W.0135.000000T0000Z-120821T0315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
810 PM MST MON AUG 20 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTH CENTRAL
MOHAVE COUNTY...

THUNDERSTORMS NEAR WIKIEUP HAVE DISSIPATED AND FLASH FLOODING IS NO 
LONGER EXPECTED. HOWEVER DUE TO THE AMOUNT OF RAIN THAT FELL 
EARLIER...MOTORISTS SHOULD USE CAUTION WHILE TRAVELING ALONG CHICKEN 
RANCH ROAD WEST OF WIKIEUP THIS EVENING AND BE ALERT FOR WATER OVER 
THE ROADWAY AND OTHER POTENTIAL PROBLEMS CAUSED BY THE EARLIER HEAVY 
RAIN.

LAT...LON 3477 11383 3479 11361 3459 11353 3456 11380

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 20, 5:51 PM MSTSevere Thunderstorm WarningVEFMohave39 min
Aug 20, 7:37 PM MSTFlash Flood WarningVEFMohave4 hr
Aug 20, 8:01 PM MSTFlash Flood WarningVEFMohave119 min
Aug 21, 11:39 AM MSTFlash Flood WatchVEFMohave36 hr
Aug 21, 1:43 PM MSTSevere Thunderstorm WarningVEFMohave32 min
Aug 21, 3:16 PM MSTFlash Flood WarningVEFMohave119 min

Nearby

Flash Flood Warnings in Arizona, 2012Every flash flood warning in 2012

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.