Alert archive / Arizona / Flash Flood Warnings in 2014

Flash Flood Warning 99, NWS Las Vegas, NV

August 12, 2014Mohave County, Arizona; San Bernardino County, California; Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 12, 2014, 4:14 PM MST for Mohave County, Arizona; San Bernardino County, California; Clark County, Nevada. It was in force for 3 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
Aug 12, 2014, 4:14 PM MST (23:14 UTC)
Expired
Aug 12, 2014, 7:15 PM MST
In force
3 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), 84 km from the middle of the area, began a volume at 23:17 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, 11.2 hours before the alert went out and 176 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 2014-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 2014-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -29 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
17 J/kg
Mixed-layer CIN
-366 J/kg
Mixed-layer LCL
2049 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
-29 m²/s²
0-3 km storm-relative helicity
94 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.4

Open this sounding in Storm Lab

The text

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

479 
WGUS55 KVEF 122314
FFWVEF
AZC015-CAC071-NVC003-130215-
/O.NEW.KVEF.FF.W.0099.140812T2314Z-140813T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
414 PM PDT TUE AUG 12 2014

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 715 PM PDT/715 PM MST/

* AT 411 PM PDT...TRAINED WEATHER SPOTTERS REPORTED FLASH FLOODING
  FROM THUNDERSTORMS ALONG A LINE EXTENDING FROM 6 MILES NORTHEAST OF
  HIGHWAY 95 AND I-40 TO NEEDLES...OR ALONG A LINE EXTENDING FROM 14
  MILES SOUTHWEST OF LAUGHLIN TO 8 MILES NORTHWEST OF TOPOCK. THE
  STORMS PRODUCING FLASH FLOODING WERE NEARLY STATIONARY.

* LOCATIONS IMPACTED INCLUDE...
  MOHAVE VALLEY...NEEDLES AND HIGHWAY 95.

THIS INCLUDES INTERSTATE 40 IN CALIFORNIA BETWEEN MILE MARKERS 132
AND 148.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON ROADS...IN NORMALLY DRY WASHES AND LOW
LYING AREAS. NEVER TRY TO CROSS A FLOODED ROAD OR ENTER A FLOOD
CHANNEL. TURN AROUND...DONT DROWN!

REPORT FLOODING TO THE LAS VEGAS NATIONAL WEATHER SERVICE VIA
FACEBOOK OR TWITTER.

&&

LAT...LON 3511 11466 3496 11461 3496 11456 3479 11451
      3473 11475 3510 11487

$$

JH
2 follow-up statements
204 
WGUS75 KVEF 130032
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
532 PM PDT TUE AUG 12 2014

AZC015-CAC071-NVC003-130215-
/O.CON.KVEF.FF.W.0099.000000T0000Z-140813T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-SAN BERNARDINO CA-CLARK NV-
532 PM PDT TUE AUG 12 2014

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 715 PM PDT/715 PM
MST/ FOR EXTREME SOUTH CENTRAL CLARK...EAST CENTRAL SAN BERNARDINO
AND SOUTHWESTERN MOHAVE COUNTIES...

TRAINED SPOTTERS REPORTED FLOODING IN THE NEEDLES AREA. A FEW 
THUNDERSTORMS CONTINUE TO MOVE INTO THE AREA. RAINFALL FROM THESE 
STORMS COMBINED WITH RUNOFF FROM EARLIER HEAVY RAIN COULD STILL 
CAUSE FLOODING.  

LOCATIONS IMPACTED INCLUDE...
NEEDLES...NEEDLES KOA CAMPGROUND AND MOHAVE VALLEY AND HIGHWAY 95 
FROM NEEDLES TO EXTREME SOUTHERN CLARK COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
ROADS. TO ESCAPE RISING WATER...MOVE TO HIGHER GROUND. NEVER TRY TO
CROSS A FLOODED ROAD OR ENTER A FLOOD CHANNEL. TURN AROUND...DONT
DROWN!

REPORT FLOODING TO THE LAS VEGAS NATIONAL WEATHER SERVICE VIA
FACEBOOK OR TWITTER.

&&

LAT...LON 3511 11466 3496 11461 3496 11456 3479 11451
      3473 11475 3510 11487

$$

JH
511 
WGUS75 KVEF 130220
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
720 PM PDT TUE AUG 12 2014

AZC015-CAC071-NVC003-130229-
/O.EXP.KVEF.FF.W.0099.000000T0000Z-140813T0215Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
MOHAVE AZ-SAN BERNARDINO CA-CLARK NV-
720 PM PDT TUE AUG 12 2014

...THE FLASH FLOOD WARNING HAS EXPIRED FOR EXTREME SOUTH CENTRAL
CLARK...EAST CENTRAL SAN BERNARDINO AND SOUTHWESTERN MOHAVE
COUNTIES...

THERE HAS BEEN NO SIGNIFICANT RAINFALL IN THE WARNING AREA FOR A 
WHILE. THERE IS STILL POTENTIAL FOR MORE STORMS TO DEVELOP THIS 
EVENING HOWEVER.

LAT...LON 3511 11466 3496 11461 3496 11456 3479 11451
      3473 11475 3510 11487

$$

JH

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 5:19 PM MSTFlash Flood WarningVEFMohave3 hr
Aug 11, 6:22 PM MSTFlash Flood WatchVEFMohave38 hr
Aug 12, 2:55 PM MSTFlash Flood WarningVEFMohave3 hr
Aug 12, 2:59 PM MSTSevere Thunderstorm WarningVEFMohave46 min
Aug 12, 3:40 PM MSTSevere Thunderstorm WarningVEFMohave40 min
Aug 12, 4:02 PM MSTFlash Flood WarningVEFMohave3 hr
Aug 12, 4:05 PM MSTSevere Thunderstorm WarningVEFMohave40 min
Aug 12, 4:43 PM MSTFlash Flood WarningVEFMohave3 hr
Aug 12, 12:40 PM MSTFlash Flood WarningVEFSan Bernardino3 hr
Aug 12, 1:16 PM MSTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 12, 2:28 PM MSTFlash Flood WarningVEFSan Bernardino3 hr
Aug 12, 2:42 PM MSTFlash Flood WarningVEFInyo3 hr
Aug 12, 4:20 PM MSTFlash Flood WarningVEFSan Bernardino3 hr
Aug 12, 4:25 PM MSTFlash Flood WarningVEFSan Bernardino3 hr
Aug 12, 4:51 PM MSTFlash Flood WarningVEFSan Bernardino3 hr
Aug 11, 8:06 PM MSTAreal Flood AdvisoryVEFClark84 min
Aug 12, 2:13 PM MSTAreal Flood AdvisoryVEFClark3 hr
Aug 12, 2:44 PM MSTFlash Flood WarningVEFClark3 hr

Nearby

Flash Flood Warnings in Arizona, 2014Flash Flood Warnings in California, 2014Flash Flood Warnings in Nevada, 2014Every flash flood warning in 2014

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.