Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 75, NWS Las Vegas, NV

July 31, 2012Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Jul 31, 2012, 2:21 PM MST for Mohave County, Arizona. It was in force for 114 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
Jul 31, 2012, 2:21 PM MST (21:21 UTC)
Expired
Jul 31, 2012, 4:15 PM MST
In force
114 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Mohave County, AZ

The radar

The Las Vegas radar (KESX), 84 km from the middle of the area, began a volume at 21:22 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 31, 3:07 PM MSTFLASH FLOODSsw Oatman, AZA SPOTTER REPORTED BOULDERS IN THE ROAD ALONG HIGHWAY 66. PORTIONS OF THE ROAD FROM BULLHEAD CITY TO OATMAM HAS BEEN WASHED OUT. IN ADDITION THE SPOTTER RECEIVED 1.80 INCHES OF RAIN IN ABOUT 1 HOUR.

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 12:00Z, 9.4 hours before the alert went out and 179 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.

283 
WGUS55 KVEF 312121
FFWVEF
AZC015-312315-
/O.NEW.KVEF.FF.W.0075.120731T2121Z-120731T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 415 PM MST.

* AT 213 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR OATMAN...OR 15 MILES
  SOUTHEAST OF BULLHEAD CITY...MOVING NORTH AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
  OATMAN.

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 3509 11452 3515 11432 3496 11430 3493 11450

$$

SC
2 follow-up statements
993 
WGUS75 KVEF 312135
FFSVEF

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

AZC015-312315-
/O.CON.KVEF.FF.W.0075.000000T0000Z-120731T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
235 PM MST TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MST FOR WEST
CENTRAL MOHAVE COUNTY...

AT 226 PM MST...THE PUBLIC REPORTED A THUNDERSTORM PRODUCING VERY 
HEAVY RAIN IN OATMAN AND ALL WASHES WERE RUNNING RAPIDLY. 
ADDITIONALLY...TWO RAIN GAGES IN THE VICINITY OF OATMAN HAVE 
RECEIVED GREATER THAN ONE HALF INCH OF RAINFALL IN 15 MINUTES. THIS 
STORM IS CAPABLE OF PRODUCING IN EXCESS ONE INCH OF RAINFALL IN 30 
MINUTES OR LESS. THIS STORM WAS LOCATED JUST NORTH OF OATMAN...OR 10 
MILES SOUTHEAST OF BULLHEAD CITY...MOVING NORTH AT 10 MPH.

LOCATIONS IMPACTED INCLUDE...
OATMAN

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 3509 11452 3515 11432 3496 11430 3493 11450

$$

SC
143 
WGUS75 KVEF 312226
FFSVEF

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

AZC015-312315-
/O.CON.KVEF.FF.W.0075.000000T0000Z-120731T2315Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
326 PM MST TUE JUL 31 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 415 PM MST FOR WEST
CENTRAL MOHAVE COUNTY...

AT 314 PM MST...NATIONAL WEATHER SERVICE RADAR INDICATED THE 
HEAVIEST RAIN HAS MOVED TO THE NORTH. A TRAINED WEATHER SPOTTER 
REPORTED 1.80 INCHES OF RAINFALL IN ONE HOUR IN OATMAN. ROCKS AND 
DEBRIS HAVE BEEN REPORTED ACROSS ROUTE 66 AND THE ROAD IS CLOSED TO 
BULLHEAD CITY.

LOCATIONS IMPACTED INCLUDE...

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 3509 11452 3515 11432 3496 11430 3493 11450

$$

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, 1:55 PM MSTFlash Flood WarningVEFMohave2 hr
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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.