Alert archive / Nevada / Flash Flood Warnings in 2008

Flash Flood Warning 49, NWS Las Vegas, NV

August 7, 2008Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Aug 7, 2008, 3:37 PM PDT for Clark County, Nevada. It was in force for 83 min. 4 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 7, 2008, 3:37 PM PDT (22:37 UTC)
Expired: Aug 7, 2008, 5:00 PM PDT
In force: 83 min
Issued by: NWS Las Vegas, NV
Area: Storm-based polygon
Flood severity: None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 50 km from the middle of the area, began a volume at 22:39 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

Time	Report	Where	Remark
Aug 7, 3:40 PM PDT	FLASH FLOOD	East Las Vegas, NV	BROADCAST MEDIA IN LAS VEGAS REPORTED THAT SEVERAL ROADS WERE FLOODED NEAR THE SAMS TOWN CASINO. THE TIME OF THIS EVENT WAS ESTIMATED.
Aug 7, 3:43 PM PDT	FLASH FLOOD	East Las Vegas, NV	SWIFT WATER RESCUE AT US 95 AND EAST FLAMINGO.
Aug 7, 3:45 PM PDT	FLASH FLOOD	2 Nnw East Las Vegas, NV	WATER IS 10 INCHES DEEP AT HARMON AND BOULDER. CARS ARE STALLING.
Aug 7, 3:45 PM PDT	FLASH FLOOD	East Las Vegas, NV	SWIFT WATER RESCUE AT BOULDER HIGHWAY AND EAST TROPICANA.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Mercury/Desert R, NV (KDRA), launched 12:00Z, 10.6 hours before the alert went out and 100 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 37 J/kg
Mixed-layer CIN: -225 J/kg
Mixed-layer LCL: 2630 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 6 m²/s²
0-3 km storm-relative helicity: 39 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.

000 
WGUS55 KVEF 072237
FFWVEF
NVC003-080030-
/O.NEW.KVEF.FF.W.0049.080807T2237Z-080808T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
337 PM PDT THU AUG 7 2008

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 530 PM PDT.

* AT 331 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER THE WARNED AREA.

* LOCATIONS IMPACTED INCLUDE...EAST LAS VEGAS...SAMS TOWN...THE
  SILVER BOWL AND UNLV.

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.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY. DO
NOT ATTEMPT TO CROSS SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN
DEPTH BY FOOT OR BY AUTOMOBILE. TURN AROUND...DONT DROWN.

LAT...LON 3617 11509 3618 11498 3609 11496 3609 11507
      3610 11514

$$
SC

2 follow-up statements

000
WGUS75 KVEF 072326
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
426 PM PDT THU AUG 7 2008

NVC003-080030-
/O.CON.KVEF.FF.W.0049.000000T0000Z-080808T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
426 PM PDT THU AUG 7 2008

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM PDT FOR
CENTRAL CLARK COUNTY...

AT 420 PM PDT...FLASH FLOODING CONTINUES IN THE EASTERN PORTIONS OF 
THE LAS VEGAS VALLEY. THE HEAVY RAINFALL HAS ENDED...BUT RUNOFF FROM 
THE EARLIER HEAVY RAIN WILL CONTINUE TO PRODUCE FLASH FLOODING. ONE 
PRIMARY AREA OF FLOODING HAS BEEN ALONG BOULDER HIGHWAY WITH SWIFT 
WATER RESCUES HAVING OCCURRED OR IN PROGRESS AT TROPICANA...FLAMINGO 
AND ENGLISH AVENUES. ADDITIONAL FLOODING AND SWIFT WATER RESCUES 
HAVE OCCURRED AT EASTERN AND HARMON AVENUE. FLASH FLOODING FROM 
RUNOFF IS EXPECTED TO CONTINUE THROUGH 530 PM.

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.

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

LAT...LON 3617 11509 3618 11498 3609 11496 3609 11507
      3610 11514

$$

SC

000
WGUS75 KVEF 080000
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
500 PM PDT THU AUG 7 2008

NVC003-080008-
/O.CAN.KVEF.FF.W.0049.000000T0000Z-080808T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
500 PM PDT THU AUG 7 2008

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR CENTRAL CLARK
COUNTY...

RUNOFF HAS BEEN DIMINISHING ACROSS THE AREA AND SHOULD NOW ONLY BE 
LIMITED TO NUISANCE FLOODING ALONG SOME ROADWAYS. EXTRA CAUTION WILL 
STILL NEED TO BE TAKEN FOR THE REMAINDER OF THE EVENING ESPECIALLY 
ALONG BOULDER HIGHWAY BETWEEN TROPICANA AND FLAMINGO...BUT THE 
THREAT OF FLASH FLOODING HAS ENDED. THEREFORE...THE FLASH FLOOD 
WARNING FOR CENTRAL CLARK COUNTY HAS BEEN CANCELLED.

LAT...LON 3617 11509 3618 11498 3609 11496 3609 11507
      3610 11514

$$

SC

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 6, 6:36 PM PDT	Flash Flood Warning	VEF	Lincoln	86 min
Aug 6, 7:52 PM PDT	Areal Flood Advisory	VEF	Clark	62 min
Aug 6, 8:27 PM PDT	Flash Flood Warning	VEF	Clark	50 min
Aug 7, 1:51 PM PDT	Areal Flood Advisory	VEF	Clark, Nye	18 min
Aug 7, 2:00 PM PDT	Flash Flood Warning	VEF	Clark	108 min
Aug 7, 2:17 PM PDT	Severe Thunderstorm Warning	VEF	Clark	23 min
Aug 7, 2:58 PM PDT	Severe Thunderstorm Warning	VEF	Clark	47 min
Aug 7, 3:05 PM PDT	Flash Flood Warning	VEF	Clark	115 min
Aug 7, 4:08 PM PDT	Flash Flood Warning	VEF	Clark	75 min

Nearby

Flash Flood Warnings in Nevada, 2008 Every flash flood warning in 2008

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.