Alert archive / Nevada / Flash Flood Warnings in 2011

Flash Flood Warning 37, NWS Las Vegas, NV

July 7, 2011Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 7, 2011, 4:37 PM PDT for Clark County, Nevada. It was in force for 53 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued: Jul 7, 2011, 4:37 PM PDT (23:37 UTC)
Expired: Jul 7, 2011, 5:30 PM PDT
In force: 53 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), 28 km from the middle of the area, began a volume at 23:40 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, 11.6 hours before the alert went out and 71 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: 34 J/kg
Mixed-layer CIN: -208 J/kg
Mixed-layer LCL: 2113 m above ground
0-6 km bulk shear: 18 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 114 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.

057 
WGUS55 KVEF 072337
FFWVEF
NVC003-080130-
/O.NEW.KVEF.FF.W.0037.110707T2337Z-110708T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
437 PM PDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  CENTRAL CLARK COUNTY IN SOUTHERN NEVADA...
  INCLUDING PORTIONS OF THE HENDERSON AND BOULDER CITY AREA

* UNTIL 630 PM PDT.

* AT 431 PM PDT...BOULDER CITY POLICE REPORTED MUD AND DEBRIS 
FLOWING ACROSS HIGHWAY 95 AT MILE MARKER 46.  ADDITIONAL HEAVY RAIN 
IS MOVING INTO THE SOUTHEASTERN HENDERSON AND BOULDER CITY AREA AND 
WILL AGGRAVATE EXISTING FLOODING AND LIKELY CAUSE NEW FLOODING. 

* LOCATIONS IMPACTED INCLUDE...HENDERSON AND BLACK MTN.

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3609 11500 3607 11490 3600 11495 3590 11482
      3576 11479 3576 11513

$$

JGG

1 follow-up statement

116 
WGUS75 KVEF 080030
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
530 PM PDT THU JUL 7 2011

NVC003-080040-
/O.CAN.KVEF.FF.W.0037.000000T0000Z-110708T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
CLARK NV-
530 PM PDT THU JUL 7 2011

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

RAINFALL HAS ENDED IN THE AREA AND LOCAL LAW ENFORCEMENT REPORT NO 
CONTINUING FLASH FLOOD PROBLEMS. THEREFORE THE WARNING IS CANCELLED.

LAT...LON 3609 11500 3607 11490 3600 11495 3590 11482
      3576 11479 3576 11513

$$

JGG

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 6, 5:48 PM PDT	Areal Flood Advisory	VEF	Clark, Nye	71 min
Jul 7, 1:01 PM PDT	Areal Flood Advisory	VEF	Clark	43 min
Jul 7, 1:16 PM PDT	Flash Flood Warning	VEF	Clark	119 min
Jul 7, 2:54 PM PDT	Severe Thunderstorm Warning	VEF	Clark	51 min
Jul 7, 3:01 PM PDT	Severe Thunderstorm Warning	VEF	Clark	33 min
Jul 7, 3:18 PM PDT	Severe Thunderstorm Warning	VEF	Clark	42 min
Jul 7, 3:32 PM PDT	Severe Thunderstorm Warning	VEF	Clark	43 min
Jul 7, 3:35 PM PDT	Flash Flood Warning	VEF	Clark	114 min
Jul 7, 4:26 PM PDT	Areal Flood Advisory	VEF	Clark	74 min
Jul 7, 4:29 PM PDT	Severe Thunderstorm Warning	VEF	Clark	46 min
Jul 7, 4:52 PM PDT	Flash Flood Warning	VEF	Clark	113 min

Nearby

Flash Flood Warnings in Nevada, 2011 Every flash flood warning in 2011

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.