Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 137, NWS Las Vegas, NV

August 20, 2012Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood warning at Aug 20, 2012, 7:37 PM MST for Mohave County, Arizona. It was in force for 4 hr. 3 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
Aug 20, 2012, 7:37 PM MST (02:37 UTC)
Expired
Aug 20, 2012, 11:30 PM MST
In force
4 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), 103 km from the middle of the area, began a volume at 02:40 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, 8:00 PM MSTHEAVY RAIN 2.765 Wnw Hualapai Mountain, AZTHE LAZY Y U MOHAVE COUNTY ALERT GAGE MEASURED 1.93 INCHES OF RAIN BETWEEN 7 AND 8 PM WITH A STORM TOTAL OF 2.76 INCHES BY 10 PM.
Aug 20, 8:15 PM MSTFLASH FLOOD5 Se Kingman, AZTRAINED SPOTTER REPORTED VERY HEAVY RAIN WITH A LOT OF WATER AND DEBRIS ON HUALAPAI ROAD BETWEEN MILE MARKERS 5 AND 6. THE ROAD WAS REPORTED AS IMPASSABLE FOR LOW CLEARANCE VEHICLES.
Aug 20, 8:24 PM MSTHEAVY RAIN 02 Sse Kingman, AZTRAINED SPOTTER REPORTED VERY HEAVY RAIN, RUNNING WATER AND LOW VISIBILITY ON HUALAPAI ROAD. WIND SPEEDS WERE ESTIMATED AT 40 TO 50 MPH.

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, 2.6 hours before the alert went out and 197 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 2012-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 633 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 2012-08-21The 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
633 J/kg
Mixed-layer CIN
-150 J/kg
Mixed-layer LCL
2388 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
30 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.

179 
WGUS55 KVEF 210237
FFWVEF
AZC015-210430-
/O.NEW.KVEF.FF.W.0137.120821T0237Z-120821T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 930 PM MST.

* AT 727 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM 6 MILES NORTHWEST OF           
  HUALAPAI MOUNTAIN PARK...OR 6 MILES SOUTHEAST OF KINGMAN ALONG THE 
  HUALAPAI MOUNTAIN ROAD. THE STORM PRODUCING VERY HEAVY RAIN WAS    
  NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
AREAS NEAR AND ALONG HUALAPAI MOUNTAIN ROAD.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. 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.

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 3519 11408 3517 11385 3505 11383 3505 11411

$$

JS
4 follow-up statements
934 
WGUS75 KVEF 210348
FFSVEF

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

AZC015-210430-
/O.CON.KVEF.FF.W.0137.000000T0000Z-120821T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
848 PM MST MON AUG 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 930 PM MST FOR
CENTRAL MOHAVE COUNTY...

AT 836 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING VERY HEAVY RAIN IN THE HUALAPAI 
MOUNTAIN ROAD AREA. THIS STORM WAS LOCATED NEAR HUALAPAI MOUNTAIN 
PARK...OR 12 MILES SOUTHEAST OF KINGMAN. A TRAINED WEATHER SPOTTER 
IN THE AREA REPORTED FLASH FLOODING AND DEBRIS ON HUALAPAI MOUNTAIN 
ROAD. THE THUNDERSTORM WITH EXCESSIVE RAIN WAS NEARLY STATIONARY.

LOCATIONS IMPACTED INCLUDE...
SOUTHEAST KINGMAN...HUALAPAI MOUNTAIN ROAD AND COUNTY ROAD 259.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. 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 3519 11408 3517 11385 3505 11383 3505 11411

$$

JS
297 
WGUS55 KVEF 210429
FFWVEF
AZC015-210630-
/O.EXT.KVEF.FF.W.0137.000000T0000Z-120821T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS EXTENDED THE

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

* UNTIL 1130 PM MST.

* AT 915 PM MST...DOPPLER RADER CONTINUED TO SHOW MODERATE TO HEAVY  
  RAIN SOUTHEAST OF KINGMAN OVER THE HUALAPAI MOUNTAIN ROAD. TRAINED 
  WEATHER SPOTTERS AND LAW ENFORCEMENT REPORTED VERY HEAVY RAIN AND  
  FLOODING IN THIS AREA. MOTORISTS SHOULD AVOID FLOODED ROADWAYS AND 
  WAIT FOR WATER TO RECEDE.

* LOCATIONS IMPACTED INCLUDE...
  AREAS SURROUNDING HUALAPAI MOUNTAIN ROAD SOUTHEAST OF KINGMAN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. 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 3519 11408 3517 11385 3505 11383 3505 11411

$$

JS
111 
WGUS75 KVEF 210554
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1054 PM MST MON AUG 20 2012

AZC015-210630-
/O.CON.KVEF.FF.W.0137.000000T0000Z-120821T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
1054 PM MST MON AUG 20 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1130 PM MST FOR
CENTRAL MOHAVE COUNTY...

AT 1041 PM MST...ONLY LIGHT RAIN WAS INDICATED OVER THE NORTHERN 
HUALAPAI MOUNTAINS BUT THE EARLIER HEAVY RAIN COULD STILL BE CAUSING 
FLOOD RELATED PROBLEMS ALONG HUALAPAI MOUNTAIN AND SECONDARY 
ROADWAYS. THE STORMS THIS EVENING PRODUCED ABUNDANT RAINFALL WITH 
MEASURED AMOUNTS IN EXCESS OF AN INCH OVER A WIDESPREAD AREA WITH 
HIGHER AMOUNTS SUCH AS 2.76 INCHES MEASURED BY THE MOHAVE COUNTY 
ALERT SYSTEM AT LAZY Y U. MOTORISTS THROUGHOUT THIS AREA SHOULD USE 
CAUTION AND REMAIN ALERT FOR WATER CROSSING THE ROADWAYS.

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 3519 11408 3517 11385 3505 11383 3505 11411

$$

JS
698 
WGUS75 KVEF 210624
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1124 PM MST MON AUG 20 2012

AZC015-210632-
/O.EXP.KVEF.FF.W.0137.000000T0000Z-120821T0630Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-
1124 PM MST MON AUG 20 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1130 PM MST FOR CENTRAL 
MOHAVE COUNTY.

HEAVY RAIN IN THE WARNED AREA HAS ENDED AND FLASH FLOODING IS NO 
LONGER EXPECTED. THE WARNING WILL BE ALLOWED TO EXPIRE ON TIME 
HOWEVER...AREA WASHES COULD STILL BE EXPERIENCING ELEVATED WATER 
LEVELS AND THERE COULD BE PONDING OF WATER ON AREAS ROADWAYS.

LAT...LON 3519 11408 3517 11385 3505 11383 3505 11411

$$

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, 6:09 PM MSTFlash Flood WarningVEFMohave2 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.