Alert archive / Nevada / Flash Flood Watches in 2012

Flash Flood Watch 2, NWS Las Vegas, NV

July 15, 2012San Bernardino County, California; Clark County, Lincoln County, Nye County, Nevada; Mohave County, Arizona

NWS Las Vegas, NV issued this flash flood watch at Jul 15, 2012, 10:14 AM PDT for San Bernardino County, California; Clark County, Lincoln County, Nye County, Nevada; Mohave County, Arizona. It was in force for 11 hr.

The area

The counties it named.

The facts

Issued
Jul 15, 2012, 10:14 AM PDT (17:14 UTC)
Expired
Jul 15, 2012, 9:00 PM PDT
In force
11 hr
Issued by
NWS Las Vegas, NV
Flood severity
None

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

The radar

The Las Vegas radar (KESX), 94 km from the middle of the area, began a volume at 17:15 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, 5.2 hours before the alert went out and 28 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 2012-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 335 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 2012-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 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
335 J/kg
Mixed-layer CIN
-212 J/kg
Mixed-layer LCL
1353 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
8 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.

230 
WGUS65 KVEF 151714
FFAVEF

URGENT - IMMEDIATE BROADCAST REQUESTED
FLOOD WATCH
NATIONAL WEATHER SERVICE LAS VEGAS NV
1014 AM PDT SUN JUL 15 2012

.CONDITIONS REMAIN FAVORABLE FOR NUMEROUS HEAVY RAIN PRODUCING
THUNDERSTORMS TO DEVELOP OVER FAR SOUTHERN NEVADA...EASTERN SAN
BERNARDINO COUNTY CALIFORNIA AND NORTHWEST ARIZONA THROUGH THIS
EVENING.

AZZ001>003-036-CAZ524>527-NVZ016-018>022-152330-
/O.NEW.KVEF.FF.A.0002.120715T1714Z-120716T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTHWEST PLATEAU-LAKE HAVASU AND FORT MOHAVE-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN MOJAVE DESERT-
MORONGO BASIN-CADIZ BASIN-SAN BERNARDINO COUNTY-
UPPER COLORADO RIVER VALLEY-NORTHEAST CLARK COUNTY-SHEEP RANGE-
SPRING MOUNTAINS-RED ROCK CANYON-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
1014 AM PDT SUN JUL 15 2012 /1014 AM MST SUN JUL 15 2012/

...FLASH FLOOD WATCH IN EFFECT UNTIL 9 PM PDT /9 PM MST/ THIS
EVENING...

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WATCH FOR PORTIONS OF NORTHWEST ARIZONA... 
  CALIFORNIA AND SOUTHERN NEVADA...INCLUDING THE FOLLOWING 
  AREAS...IN NORTHWEST ARIZONA...LAKE HAVASU AND FORT MOHAVE... 
  LAKE MEAD NATIONAL RECREATION AREA...NORTHWEST DESERTS AND 
  NORTHWEST PLATEAU. IN CALIFORNIA...CADIZ BASIN...EASTERN 
  MOJAVE DESERT...MORONGO BASIN AND SAN BERNARDINO COUNTY-UPPER 
  COLORADO RIVER VALLEY. IN SOUTHERN NEVADA...LAKE MEAD NATIONAL 
  RECREATION AREA...LAS VEGAS VALLEY...NORTHEAST CLARK COUNTY... 
  SHEEP RANGE...SOUTHERN CLARK COUNTY AND SPRING MOUNTAINS-RED 
  ROCK CANYON. 

* UNTIL 9 PM PDT /9 PM MST/ THIS EVENING

* A DEEP MOIST AND UNSTABLE AIR MASS WILL REMAIN IN PLACE OVER THE
  WATCH AREA TODAY WHILE A LOW PRESSURE SYSTEM CIRCULATES ALONG
  THE CENTRAL CALIFORNIA COAST. DISTURBANCES EJECTING OUT OF THE
  SYSTEM WILL LIKELY AID THE DEVELOPMENT OF HEAVY RAIN PRODUCING
  THUNDERSTORMS THIS AFTERNOON AND EVENING. BETWEEN ONE AND TWO
  INCHES OF RAINFALL CAN BE EXPECTED WITH THE STRONGEST STORMS.

* TRAVELERS SHOULD BE ALERT FOR THE POTENTIAL FOR WATER TO COVER
  LOW SPOTS INCLUDING ANY ROADS THAT RUN THROUGH WASHES. ROCKS AND
  MUD MAY WASH ONTO ROADS DUE TO RUNOFF. DIRT AND GRAVEL SECONDARY
  ROADS MAY WASH OUT OR BE IMPASSIBLE. STORM DRAINS AND FLOOD
  CONTROL CHANNELS COULD SEE RAPIDLY FLOWING WATER IN THEM ALONG
  WITH THE POTENTIAL FOR DEBRIS TO COLLECT IN THEM. IN ADDITION...
  RUNOFF MAY CAUSE FLOODING WELL DOWNSTREAM FROM WHERE ANY RAIN
  FALLS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION
AND PERSONS IN AND NEAR THE WATCH AREA SHOULD BE ALERT TO THE
POTENTIAL FOR HEAVY RAINFALL.

&&

$$
2 follow-up statements
922 
WGUS65 KVEF 152312
FFAVEF

FLOOD WATCH
NATIONAL WEATHER SERVICE LAS VEGAS NV
412 PM PDT SUN JUL 15 2012

.CONDITIONS REMAIN FAVORABLE FOR NUMEROUS HEAVY RAIN PRODUCING
THUNDERSTORMS TO DEVELOP OVER FAR SOUTHERN NEVADA...EASTERN SAN
BERNARDINO COUNTY CALIFORNIA AND NORTHWEST ARIZONA THROUGH THIS
EVENING.

AZZ001>003-036-CAZ524>527-NVZ016-018>022-160400-
/O.CON.KVEF.FF.A.0002.000000T0000Z-120716T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTHWEST PLATEAU-LAKE HAVASU AND FORT MOHAVE-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN MOJAVE DESERT-
MORONGO BASIN-CADIZ BASIN-SAN BERNARDINO COUNTY-
UPPER COLORADO RIVER VALLEY-NORTHEAST CLARK COUNTY-SHEEP RANGE-
SPRING MOUNTAINS-RED ROCK CANYON-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
412 PM PDT SUN JUL 15 2012 /412 PM MST SUN JUL 15 2012/

...FLASH FLOOD WATCH REMAINS IN EFFECT UNTIL 9 PM PDT /9 PM MST/
THIS EVENING...

THE FLASH FLOOD WATCH CONTINUES FOR

* PORTIONS OF NORTHWEST ARIZONA...CALIFORNIA AND SOUTHERN 
  NEVADA...INCLUDING THE FOLLOWING AREAS...IN NORTHWEST 
  ARIZONA...LAKE HAVASU AND FORT MOHAVE...LAKE MEAD NATIONAL 
  RECREATION AREA...NORTHWEST DESERTS AND NORTHWEST PLATEAU. IN 
  CALIFORNIA...CADIZ BASIN...EASTERN MOJAVE DESERT...MORONGO 
  BASIN AND SAN BERNARDINO COUNTY-UPPER COLORADO RIVER VALLEY. 
  IN SOUTHERN NEVADA...LAKE MEAD NATIONAL RECREATION AREA...LAS 
  VEGAS VALLEY...NORTHEAST CLARK COUNTY...SHEEP RANGE...SOUTHERN 
  CLARK COUNTY AND SPRING MOUNTAINS-RED ROCK CANYON. 

* UNTIL 9 PM PDT /9 PM MST/ THIS EVENING

* A DEEP MOIST AND UNSTABLE AIR MASS WILL REMAIN OVER THE WATCH
  AREA WHILE A LOW PRESSURE SYSTEM CIRCULATES ALONG THE CENTRAL
  CALIFORNIA COAST. DISTURBANCES EJECTING OUT OF THE SYSTEM WILL
  LIKELY AID THE DEVELOPMENT OF HEAVY RAIN PRODUCING THUNDERSTORMS
  THROUGH THIS EVENING. BETWEEN ONE AND TWO INCHES OF RAINFALL
  CAN BE EXPECTED WITH THE STRONGEST STORMS.

* TRAVELERS SHOULD BE ALERT FOR THE POTENTIAL FOR WATER TO COVER 
  LOW SPOTS INCLUDING ANY ROADS THAT RUN THROUGH WASHES. ROCKS 
  AND MUD MAY WASH ONTO ROADS DUE TO RUNOFF. DIRT AND GRAVEL 
  SECONDARY ROADS MAY WASH OUT OR BE IMPASSIBLE. STORM DRAINS 
  AND FLOOD CONTROL CHANNELS COULD SEE RAPIDLY FLOWING WATER IN 
  THEM ALONG WITH THE POTENTIAL FOR DEBRIS TO COLLECT IN THEM. 
  IN ADDITION... RUNOFF MAY CAUSE FLOODING WELL DOWNSTREAM FROM 
  WHERE ANY RAIN FALLS. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD
TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION
AND PERSONS IN AND NEAR THE WATCH AREA SHOULD BE ALERT TO THE
POTENTIAL FOR HEAVY RAINFALL.

&&

$$

JA
507 
WGUS65 KVEF 160340
FFAVEF

FLOOD WATCH
NATIONAL WEATHER SERVICE LAS VEGAS NV
840 PM PDT SUN JUL 15 2012

AZZ001>003-036-CAZ524>527-NVZ016-018>022-160445-
/O.EXP.KVEF.FF.A.0002.000000T0000Z-120716T0400Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
NORTHWEST PLATEAU-LAKE HAVASU AND FORT MOHAVE-NORTHWEST DESERTS-
LAKE MEAD NATIONAL RECREATION AREA-EASTERN MOJAVE DESERT-
MORONGO BASIN-CADIZ BASIN-SAN BERNARDINO COUNTY-
UPPER COLORADO RIVER VALLEY-NORTHEAST CLARK COUNTY-SHEEP RANGE-
SPRING MOUNTAINS-RED ROCK CANYON-LAS VEGAS VALLEY-
SOUTHERN CLARK COUNTY-
840 PM PDT SUN JUL 15 2012 /840 PM MST SUN JUL 15 2012/

...FLASH FLOOD WATCH WILL EXPIRE AT 9 PM PDT /9 PM MST/ THIS
EVENING...

THE FLASH FLOOD WATCH FOR PORTIONS OF NORTHWEST ARIZONA...
CALIFORNIA AND SOUTHERN NEVADA WILL EXPIRE AT 9 PM PDT /9 PM MST/
THIS EVENING. 

THUNDERSTORM ACTIVITY HAS DECREASED SIGNIFICANTLY THIS EVENING. ISOLATED
THUNDERSTORMS ARE STILL POSSIBLE TONIGHT BUT THE THREAT OF
WIDESPREAD FLASH FLOODING HAS ENDED.

$$

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 14, 7:25 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 14, 8:50 PM PDTAreal Flood AdvisoryVEFSan Bernardino27 min
Jul 14, 9:16 PM PDTFlash Flood WarningVEFSan Bernardino119 min
Jul 14, 11:35 PM PDTSevere Thunderstorm WarningVEFSan Bernardino40 min
Jul 15, 12:29 AM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 15, 11:52 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 15, 11:59 AM PDTFlash Flood WarningVEFInyo2 hr
Jul 15, 2:20 PM PDTAreal Flood AdvisoryVEFSan Bernardino115 min
Jul 15, 3:07 PM PDTSevere Thunderstorm WarningVEFSan Bernardino38 min
Jul 15, 4:52 PM PDTSevere Thunderstorm WarningVEFSan Bernardino38 min
Jul 14, 6:02 PM PDTAreal Flood AdvisoryVEFClark116 min
Jul 14, 8:41 PM PDTAreal Flood AdvisoryVEFClark16 min
Jul 14, 8:56 PM PDTFlash Flood WarningVEFClark109 min
Jul 15, 10:30 AM PDTFlash Flood WarningVEFLincoln4 hr
Jul 15, 1:12 PM PDTFlash Flood WarningVEFClark2 hr
Jul 15, 1:24 PM PDTFlash Flood WarningVEFNye4 hr
Jul 15, 1:58 PM PDTFlash Flood WarningVEFLincoln82 min
Jul 15, 2:16 PM PDTSevere Thunderstorm WarningVEFClark44 min
Jul 15, 2:41 PM PDTAreal Flood AdvisoryVEFClark3 hr
Jul 15, 3:01 PM PDTFlash Flood WarningVEFLincoln6 hr
Jul 15, 4:40 PM PDTFlash Flood WarningVEFClark65 min
Jul 15, 4:58 PM PDTFlash Flood WarningVEFClark92 min
Jul 14, 5:10 PM PDTFlash Flood WarningVEFMohave3 hr
Jul 14, 5:30 PM PDTFlash Flood WarningVEFMohave2 hr
Jul 14, 6:36 PM PDTFlash Flood WarningVEFMohave114 min
Jul 14, 8:20 PM PDTFlash Flood WarningVEFMohave115 min
Jul 14, 10:01 PM PDTFlash Flood WarningVEFMohave3 hr
Jul 15, 12:53 PM PDTFlash Flood WarningVEFMohave2 hr

Nearby

Flash Flood Watches in Nevada, 2012Flash Flood Watches in California, 2012Flash Flood Watches in Arizona, 2012Every flash flood watch 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.