Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 16, NWS Las Vegas, NV

July 19, 2017Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 19, 2017, 6:49 AM PDT for Clark County, Nevada. It was in force for 3 hr. 2 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
Jul 19, 2017, 6:49 AM PDT (13:49 UTC)
Expired
Jul 19, 2017, 9:45 AM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County Clark County, NV

The radar

The Las Vegas radar (KESX), 52 km from the middle of the area, began a volume at 13:53 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

TimeReportWhereRemark
Jul 19, 7:12 AM PDTFLASH FLOOD2 Nw Railroad Pass, NVNEVADA DEPARTMENT OF TRANSPORTATION REPORTED SOUTHBOUND US 95 OFF-RAMP TO WAGON WHEEL IN HENDERSON CLOSED DUE TO FLOODING.
Jul 19, 7:30 AM PDTFLASH FLOOD3 Se Henderson, NVWATER WASHED MUD OVER ROADS NEAR EQUESTRIAN DR AND MAGIC WAY. TIME ESTIMATED FROM RADAR.

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

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 1.8 hours before the alert went out and 56 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 2017-07-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 539 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 2017-07-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -39 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
539 J/kg
Mixed-layer CIN
-200 J/kg
Mixed-layer LCL
2329 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-39 m²/s²
0-3 km storm-relative helicity
67 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

790 
WGUS55 KVEF 191349
FFWVEF
NVC003-191645-
/O.NEW.KVEF.FF.W.0016.170719T1349Z-170719T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
649 AM PDT WED JUL 19 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Central Clark County in southern Nevada...

* Until 945 AM PDT

* At 647 AM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across southeast Henderson and additional thunderstorms 
  moving into the northeast Las Vegas Valley. Rainfall rates up to 2 
  inches per hour are estimated with these storms. Flash flooding is 
  expected to begin shortly over parts of the the east side of the 
  Las Vegas Valley.

* Some locations that will experience flooding include...
  Las Vegas, Henderson, North Las Vegas, Boulder City, Anthem, Lake
  Las Vegas, Nellis AFB, Green Valley, East Las Vegas, Sam Boyd
  Stadium, The Motor Speedway, Paradise, Railroad Pass, Las Vegas Bay
  Campground, Black Mtn, Sunrise Mtn and Frenchman Mtn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3635 11487 3590 11486 3591 11511 3633 11513

$$

JA
3 follow-up statements
269 
WGUS75 KVEF 191452
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
752 AM PDT WED JUL 19 2017

NVC003-191645-
/O.CON.KVEF.FF.W.0016.000000T0000Z-170719T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
752 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 AM PDT FOR
CENTRAL CLARK COUNTY...

At 748 AM PDT, automated rain gages reported around 1 inch of rain 
had fallen in parts of Henderson and local law enforcement reported 
flash flooding near Wagon Wheel Drive and Highway 95. Thunderstorms 
with heavy rain were expanding over the east central part of the Las 
Vegas and flash flooding will become more extensive.

Some locations that will experience flooding include...
Anthem, Lake Las Vegas, Green Valley, East Las Vegas, Railroad Pass, 
Black Mountain, Sunrise Mountain and Frenchman Mountain.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3635 11487 3590 11486 3591 11511 3633 11513

$$

JA
726 
WGUS75 KVEF 191540
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
840 AM PDT WED JUL 19 2017

NVC003-191645-
/O.CON.KVEF.FF.W.0016.000000T0000Z-170719T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
840 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 945 AM PDT FOR
CENTRAL CLARK COUNTY...

At 836 AM PDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain over the warned area with Anthem, 
Madeira Canyon, Seven Hills and Inspirada receiving on average 1.00 
to 1.50 inches of rain so far. 

Some locations that will experience flooding include...
Las Vegas, Henderson, North Las Vegas, Boulder City, Anthem, Lake Las
Vegas, Nellis AFB, Green Valley, East Las Vegas, Sam Boyd Stadium,
The Motor Speedway, Paradise, Railroad Pass, Las Vegas Bay
Campground, Black Mtn, Sunrise Mtn and Frenchman Mtn.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood
deaths occur in vehicles.

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, urban areas, highways, streets and underpasses as
well as other drainage areas and low lying spots.

&&

LAT...LON 3635 11487 3590 11486 3591 11511 3633 11513

$$

Czyzyk
104 
WGUS75 KVEF 191643
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
943 AM PDT WED JUL 19 2017

NVC003-191646-
/O.EXP.KVEF.FF.W.0016.000000T0000Z-170719T1645Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
943 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING FOR CENTRAL CLARK COUNTY WILL EXPIRE AT
945 AM PDT...

The heavy rain has ended across much of the Las Vegas Valley 
although lighter rain continues across much of Henderson and the 
southern portions of the valley. Flood waters are receding but 
ponded water and minor flooding will continue for the remainder of 
the morning. The flash flood warning for central Clark County will 
be allowed to expire at 945 AM PDT, but a separate flash flood 
warning remains in effect for the far southern portions of the Las 
Vegas Valley, primarily along and south of St. Rose Parkway. Please 
continue to heed any remaining road closures.

LAT...LON 3635 11487 3590 11486 3591 11511 3633 11513

$$

Czyzyk

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 5:14 PM PDTSevere Thunderstorm WarningVEFClark35 min
Jul 18, 6:01 PM PDTFlash Flood WarningVEFClark3 hr
Jul 19, 5:30 AM PDTAreal Flood AdvisoryVEFClark3 hr
Jul 19, 6:23 AM PDTFlash Flood WarningVEFClark5 hr
Jul 19, 8:32 AM PDTFlash Flood WarningVEFClark3 hr
Jul 19, 8:53 AM PDTFlash Flood WarningVEFClark3 hr
Jul 19, 9:57 AM PDTFlash Flood WarningVEFClark3 hr

Nearby

Flash Flood Warnings in Nevada, 2017Every flash flood warning in 2017

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.