Alert archive / Arizona / Flash Flood Warnings in 2012

Flash Flood Warning 209, NWS Las Vegas, NV

September 11, 2012Mohave County, Arizona; Clark County, Nevada; San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Sep 11, 2012, 5:43 PM MST for Mohave County, Arizona; Clark County, Nevada; San Bernardino County, California. 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
Sep 11, 2012, 5:43 PM MST (00:43 UTC)
Expired
Sep 11, 2012, 7:45 PM MST
In force
2 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

Counties Mohave County, AZ, San Bernardino County, CA, Clark County, NV

The radar

The Las Vegas radar (KESX), 75 km from the middle of the area, began a volume at 00:45 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
Sep 11, 7:00 PM MSTFLASH FLOOD2 Nne Mohave Valley, AZSPOTTER REPORTED WATER AND DEBRIS FLOWING ACROSS HIGHWAY 95 IN MULTIPLE PLACES WHERE WASHES FLOW ACROSS THE HIGHWAY.

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 166 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 2012-09-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 352 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 2012-09-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -59 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
352 J/kg
Mixed-layer CIN
-73 J/kg
Mixed-layer LCL
827 m above ground
0-6 km bulk shear
32 kt
0-1 km storm-relative helicity
-59 m²/s²
0-3 km storm-relative helicity
0 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

553 
WGUS55 KVEF 120043
FFWVEF
AZC015-CAC071-NVC003-120245-
/O.NEW.KVEF.FF.W.0209.120912T0043Z-120912T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
543 PM PDT TUE SEP 11 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTHWESTERN MOHAVE COUNTY IN NORTHWEST ARIZONA...
  EAST CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...
  EXTREME SOUTH CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...

* UNTIL 745 PM PDT/745 PM MST/.

* AT 541 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A LINE OF THUNDERSTORMS FROM LAUGHLIN TO 
  NEEDLES. THESE THUNDERSTORMS WERE MOVING SOUTHEAST AT 10 MPH.

* LOCATIONS IMPACTED INCLUDE...
  RIVERSIDE ADVENTURE RV PARK...HIGHWAY 95 AND I-40...MOHAVE
  VALLEY...NEEDLES KOA CAMPGROUND AND NEEDLES.

THIS INCLUDES INTERSTATE 40 IN CALIFORNIA BETWEEN MILE MARKERS 130
AND 145.

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 3506 11489 3526 11477 3523 11453 3481 11449
      3481 11482

$$

JA
2 follow-up statements
201 
WGUS75 KVEF 120131
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
631 PM PDT TUE SEP 11 2012

AZC015-CAC071-NVC003-120245-
/O.CON.KVEF.FF.W.0209.000000T0000Z-120912T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-SAN BERNARDINO CA-CLARK NV-
631 PM PDT TUE SEP 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 745 PM PDT /745 PM 
MST/ FOR EXTREME SOUTH CENTRAL CLARK...EAST CENTRAL SAN BERNARDINO 
AND SOUTHWESTERN MOHAVE COUNTIES...

AT 624 PM...DOPPLER RADAR INDICATED THUNDERSTORMS PRODUCING VERY
HEAVY RAIN WILL MOVE TO THE SOUTHEAST AT 10 MPH AND EXIT THE AREA 
FROM BULLHEAD CITY DOWN THROUGH MOHAVE VALLEY AND NEEDLES BY 730 PM.
RAINFALL AMOUNTS OVER ONE INCH IN 30 MINUTES CAN BE EXPECTED WITH 
THESE STORMS WHICH WILL RESULT IN FLASH FLOODING ALONG STATE ROUTE 
95 BETWEEN NEEDLES AND BULLHEAD CITY. OTHER LOCATIONS IMPACTED 
INCLUDE NEEDLES...MOHAVE VALLEY...FORT MOHAVE...LAUGHLIN AND 
BULLHEAD CITY.

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 3506 11489 3526 11477 3523 11453 3481 11449
      3481 11482

$$

JA
952 
WGUS75 KVEF 120241
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
741 PM PDT TUE SEP 11 2012

AZC015-CAC071-NVC003-120250-
/O.EXP.KVEF.FF.W.0209.000000T0000Z-120912T0245Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-SAN BERNARDINO CA-CLARK NV-
741 PM PDT TUE SEP 11 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 745 PM PDT/745 PM MST/ FOR 
EXTREME SOUTH CENTRAL CLARK - EAST CENTRAL SAN BERNARDINO AND 
SOUTHWESTERN MOHAVE COUNTIES...

AT 740 PM PDT...RADAR INDICATED THAT RAIN HAD ENDED NEAR THE ARIZONA 
CALIFORNIA NEVADA TRIPLE POINT. THEREFORE...THE FLASH FLOOD WARNING 
WILL BE ALLOWED TO EXPIRE.

AT 700 PM...A SPOTTER IN MOHAVE VALLEY REPORTED WATER AND DEBRIS 
FLOWING ACROSS ARIZONA HIGHWAY 95.

LAT...LON 3506 11489 3526 11477 3523 11453 3481 11449
      3481 11482

$$

MORGAN

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 6:11 PM MSTAreal Flood WarningVEFClark10 hr
Sep 11, 5:25 PM MSTSevere Thunderstorm WarningVEFSan Bernardino35 min
Sep 11, 5:54 PM MSTSevere Thunderstorm WarningVEFSan Bernardino19 min
Sep 11, 6:41 PM MSTFlash Flood WarningVEFInyo2 hr
Sep 11, 7:54 PM MSTFlash Flood WarningVEFInyo71 min
Sep 11, 8:36 PM MSTSevere Thunderstorm WarningVEFSan Bernardino39 min
Sep 11, 9:59 PM MSTSevere Thunderstorm WarningVEFSan Bernardino76 min
Sep 11, 11:02 PM MSTFlash Flood WarningVEFSan Bernardino118 min

Nearby

Flash Flood Warnings in Arizona, 2012Flash Flood Warnings in Nevada, 2012Flash Flood Warnings in California, 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.