Alert archive / Nevada / Flash Flood Warnings in 2007

Flash Flood Warning 40, NWS Las Vegas, NV

August 27, 2007Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 27, 2007, 8:42 AM PDT for Clark County, Nevada. It took effect at Aug 27, 2007, 8:48 AM PDT. It was in force for 117 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
Aug 27, 2007, 8:42 AM PDT (15:42 UTC)
In effect from
Aug 27, 2007, 8:48 AM PDT
Expired
Aug 27, 2007, 10:45 AM PDT
In force
117 min
Issued by
NWS Las Vegas, NV
Area
Whole counties

County Clark County, NV

The radar

The Las Vegas radar (KESX), 58 km from the middle of the area, began a volume at 15:45 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.

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 3.7 hours before the alert went out and 99 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, Mercury/Desert R, NV at 12:00Z on 2007-08-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 85 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, Mercury/Desert R, NV at 12:00Z on 2007-08-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 75 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
85 J/kg
Mixed-layer CIN
-197 J/kg
Mixed-layer LCL
1937 m above ground
0-6 km bulk shear
24 kt
0-1 km storm-relative helicity
75 m²/s²
0-3 km storm-relative helicity
148 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
WGUS55 KVEF 271548
FFWVEF
NVC003-271745-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
842 AM PDT MON AUG 27 2007

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS EXTENDED THE

* FLASH FLOOD WARNING FOR...
  CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...

* UNTIL 1045 AM PDT.

* AT 839 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  MODERATE TO HEAVY RAINFALL FROM A THUNDERSTORM OVER THE SOUTHWEST  
  PORTION OF THE LAS VEGAS VALLEY NEAR SPRING VALLEY. THE STORM WAS  
  MOVING NORTHEAST AT 15 MPH AND WILL IMPACT THE LAS VEGAS STRIP AND 
  DOWNTOWN BETWEEN 900 AND 930 AM PDT. THIS ADDITIONAL RAINFALL WILL 
  AGGRAVATE THOSE AREAS THAT HAVE ALREADY OBSERVED FLASH FLOODING. 
  RUNOFF FROM EARLIER RAINFALL CONTINUES TO PRODUCE FLOODING         
  PARTICULARLY ALONG KOVAL LANE JUST TO THE EAST OF THE LAS VEGAS    
  STRIP.

* OTHER LOCATIONS IMPACTED INCLUDE...DOWNTOWN LAS VEGAS...NWS LAS
  VEGAS...SPRING VALLEY...STRATOSPHERE TOWER...THE LAKES...THE STRIP
  AND UNLV.

ADDITIONAL RAINFALL AMOUNTS OF ONE QUARTER TO ONE HALF INCH ARE 
LIKELY WITH LOCALIZED HIGHER AMOUNTS IN THE WARNED AREA.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE WATER COVERS THE ROADWAY.
THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS SAFELY.
TURN AROUND...DONT DROWN.

DO NOT UNDERESTIMATE THE POWER OF FLOOD WATERS. SEVERAL INCHES OF
RAPIDLY FLOWING WATER CAN QUICKLY CARRY AWAY YOUR VEHICLE. TURN
AROUND...DONT DROWN.

LAT...LON 3596 11534 3611 11506 3624 11510 3616 11534

$$
SC
2 follow-up statements
000
WGUS75 KVEF 271706
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
955 AM PDT MON AUG 27 2007

NVC003-271745-
CLARK NV-
955 AM PDT MON AUG 27 2007

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1045 AM PDT FOR
CENTRAL CLARK COUNTY...

AT 955 AM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED THE 
MAIN AREA OF THUNDERSTORMS IS CONTINUING TO MOVE AWAY FROM THE LAS 
VEGAS VALLEY AND INTO ARIZONA. RUNOFF CONTINUES TO PRODUCE FLOODING 
FROM EARLIER RAINFALL BUT THIS FLOODING HAS BEEN SUBSIDING AND THAT 
TREND IS EXPECTED TO CONTINUE. THE FLAMINGO AND TROPICANA WASHES 
CONTINUE TO RUN VERY HIGH IN AND AROUND THE LAS VEGAS STRIP. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO THE LAKES AND
THE LAS VEGAS VEGAS STRIP.

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE 
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS 
SAFELY. MOVE TO HIGHER GROUND.

LAT...LON 3596 11534 3611 11506 3624 11510 3616 11534

$$

SC
000
WGUS75 KVEF 271743
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
1043 AM PDT MON AUG 27 2007

NVC003-271748-
CLARK NV-
1043 AM PDT MON AUG 27 2007

...THE FLASH FLOOD WARNING WILL EXPIRE AT 1045 AM PDT(1045 AM MST)
FOR CENTRAL CLARK COUNTY...

THUNDERSTORM ACTIVITY HAS ENDED ACROSS CENTRAL CLARK COUNTY WITH 
LITTLE ADDITIONAL RAINFALL BEING REPORTED DURING THE PAST HOUR. THIS 
HAS ALLOWED FOR THE ENDING OF THE FLOOD WARNING FOR THE AREA.

ALTHOUGH THE FLASH FLOOD WARNING HAS BEEN ALLOWED TO EXPIRE...MANY 
OF THE AREAS WASHES ESPECIALLY OVER THE EASTERN PORTION OF THE LAS 
VEGAS VALLEY...WILL CONTINUE TO CONTAIN RUNOFF THROUGH THE REMAINDER 
OF THE MORNING AND INTO EARLY AFTERNOON. IN ADDITION...PONDING OF 
WATER WILL LIKELY BE ENCOUNTERED FOR SEVERAL HOURS.

MOTORIST ARE STILL URGED TO USE CAUTION THROUGH THE AFTERNOON AS THE 
WATER RECEDES FROM THE AREA.

LAT...LON 3596 11534 3611 11506 3624 11510 3616 11534

$$

JENSEN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 3:12 AM PDTFlash Flood WarningVEFClark93 min
Aug 27, 3:54 AM PDTFlash Flood WarningVEFClark2 hr
Aug 27, 4:40 AM PDTFlash Flood WarningVEFClark2 hr
Aug 27, 6:44 AM PDTFlash Flood WarningVEFClark2 hr

Nearby

Flash Flood Warnings in Nevada, 2007Every flash flood warning in 2007

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.