Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 73, NWS Las Vegas, NV

July 31, 2012Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 31, 2012, 1:55 PM MST for Mohave County, Arizona. It was in force for 2 hr. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 31, 2012, 1:55 PM MST (20:55 UTC)
Expired
Jul 31, 2012, 4:00 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), 99 km from the middle of the area, began a volume at 20:55 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 8.9 hours before the alert went out and 160 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 12:00Z on 2012-07-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 121 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 12:00Z on 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -5 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
121 J/kg
Mixed-layer CIN
-75 J/kg
Mixed-layer LCL
1334 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-5 m²/s²
0-3 km storm-relative helicity
-43 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.

706 
WGUS55 KVEF 312055
FFWVEF
AZC015-312300-
/O.NEW.KVEF.FF.W.0073.120731T2055Z-120731T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
155 PM MST TUE JUL 31 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 400 PM MST.

* AT 143 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER CENTRAL MOHAVE COUNTY...OR
  50 MILES NORTH OF KINGMAN OR 8 MILES SOUTHWEST OF THE GRAND CANYON 
  SKYWALK. THE STORM PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  MAINLY RURAL AREAS OF CENTRAL MOHAVE COUNTY.

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 3601 11394 3600 11374 3592 11370 3582 11388

$$

SC
2 follow-up statements
861 
WGUS75 KVEF 312154
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
254 PM MST TUE JUL 31 2012

AZC015-312300-
/O.CON.KVEF.FF.W.0073.000000T0000Z-120731T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
254 PM MST TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 400 PM MST FOR
CENTRAL MOHAVE COUNTY...

AT 244 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE 
ORIGINAL THUNDERSTORM HAS MOVED TO THE NORTH OF THE AREA...HOWEVER 
ADDITIONAL THUNDERSTORMS ARE MOVING INTO THE WARNED AREA FROM THE 
SOUTH. RUNOFF FROM THE EARLIER THUNDERSTORM IS STILL LIKELY CAUSING 
FLOODING.

LOCATIONS IMPACTED INCLUDE...
RURAL AREAS OF MOHAVE COUNTY...JUST SOUTH OF THE GRAND CANYON 
SKYWALK. 

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 3601 11394 3600 11374 3592 11370 3582 11388

$$

SC
862 
WGUS75 KVEF 312259
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
359 PM MST TUE JUL 31 2012

AZC015-312306-
/O.EXP.KVEF.FF.W.0073.000000T0000Z-120731T2300Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
359 PM MST TUE JUL 31 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 400 PM MST FOR CENTRAL
MOHAVE COUNTY...

RUNOFF FROM EARLIER THUNDERSTORMS SHOULD HAVE DIMINISHED AND ANY 
FLASH FLOODING SHOULD HAVE ENDED. THE FLASH FLOOD WARNING WILL BE 
ALLOWED TO EXPIRE AT 400 PM MST. 

LAT...LON 3601 11394 3600 11374 3592 11370 3582 11388

$$

SC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 31, 2:29 AM MSTFlash Flood WatchVEFMohave19 hr
Jul 31, 12:14 PM MSTAreal Flood AdvisoryVEFMohave83 min
Jul 31, 2:21 PM MSTFlash Flood WarningVEFMohave114 min
Jul 31, 2:42 PM MSTFlash Flood WarningVEFMohave3 hr
Jul 31, 2:48 PM MSTFlash Flood WarningVEFMohave3 hr
Jul 31, 3:12 PM MSTAreal Flood AdvisoryVEFMohave113 min
Jul 31, 3:24 PM MSTFlash Flood WarningVEFMohave111 min
Jul 31, 4:15 PM MSTFlash Flood WarningVEFMohave2 hr
Jul 31, 4:29 PM MSTFlash Flood WarningVEFMohave2 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.