Alert archive / Nevada / Flash Flood Warnings in 2018

Flash Flood Warning 87, NWS Las Vegas, NV

July 29, 2018Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 29, 2018, 3:28 PM PDT for Clark County, Nevada. It was in force for 3 hr. 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
Jul 29, 2018, 3:28 PM PDT (22:28 UTC)
Expired
Jul 29, 2018, 6:30 PM 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), 54 km from the middle of the area, began a volume at 22:32 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 29, 3:44 PM PDTHEAVY RAIN 1.024 Ene Spring Mountain R, NV1.02 INCHES OF RAIN FELL IN 30 MINUTES ON BLUE DIAMOND RIDGE.
Jul 29, 4:10 PM PDTFLASH FLOOD3 Ese Spring Mountain R, NVSR 159 0.5 MILE WEST OF BLUE DIAMOND HAS 4 TO 6 INCHES OF MUD...ROCKS...WATER FLOWING SWIFTLY ACROSS ROAD.
Jul 29, 4:10 PM PDTFLASH FLOOD3 Ese Spring Mountain R, NVSR 159 1/2 MILE WEST OF BLUE DIAMOND HAS 4-6 INCHES OF MUD...ROCKS...WATER FLOWING SWIFTLY ACROSS ROAD.
Jul 29, 5:00 PM PDTFLASH FLOOD4 Ese Spring Mountain R, NVFLASH FLOOD ON ARROYO RD IN BLUE DIAMOND. REPORTED VIA TWITTER.

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, 10.5 hours before the alert went out and 43 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 2018-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 835 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 2018-07-29The 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
835 J/kg
Mixed-layer CIN
-233 J/kg
Mixed-layer LCL
2562 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
77 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

173 
WGUS55 KVEF 292228
FFWVEF
NVC003-300130-
/O.NEW.KVEF.FF.W.0087.180729T2228Z-180730T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
328 PM PDT SUN JUL 29 2018

The National Weather Service in Las Vegas has issued a

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

* Until 630 PM PDT.

* At 327 PM PDT, Doppler radar indicated thunderstorms producing
  heavy rain across the warned area. Flash flooding is expected to
  begin shortly.

* Some locations that will experience flooding include...
  Blue Diamond, Enterprise, Mountains Edge, Red Rock Canyon, Spring
  Valley, Summerlin and Spring Mountain Ranch.

Additional rainfall amounts of one to two inches are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3605 11527 3597 11521 3589 11537 3599 11545
      3611 11548 3611 11534

$$

AB
3 follow-up statements
982 
WGUS75 KVEF 292302
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
402 PM PDT SUN JUL 29 2018

NVC003-300130-
/O.CON.KVEF.FF.W.0087.000000T0000Z-180730T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
402 PM PDT SUN JUL 29 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT FOR
CENTRAL CLARK COUNTY...

At 401 PM PDT, Rain gauges have reported up to one inch of rain so 
far. Flash flooding is expected to begin shortly.

Some locations that will experience flooding include...
Blue Diamond, Enterprise, Mountains Edge, Red Rock Canyon, Spring
Valley, Summerlin and Spring Mountain Ranch.

Additional rainfall amounts up to an inche are possible in the 
warned area.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3605 11527 3597 11521 3589 11537 3599 11545
      3611 11548 3611 11534

$$

AB
743 
WGUS75 KVEF 300008
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
508 PM PDT SUN JUL 29 2018

NVC003-300130-
/O.CON.KVEF.FF.W.0087.000000T0000Z-180730T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
508 PM PDT SUN JUL 29 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 630 PM PDT FOR
CENTRAL CLARK COUNTY...

At 505 PM PDT, National Weather Service radar indicted the 
thunderstorms have diminished, but the flash flooding threat 
continues. The public reported mud, rocks and debris flow swiftly 
across state route 159 one half mile west of Blue Diamond. 

Some locations that will experience flooding include...
Blue Diamond, Enterprise, Mountains Edge, Red Rock Canyon, Spring
Valley, Summerlin and Spring Mountain Ranch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3605 11527 3597 11521 3589 11537 3599 11545
      3611 11548 3611 11534

$$

SC
474 
WGUS75 KVEF 300128
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
628 PM PDT SUN JUL 29 2018

NVC003-300133-
/O.EXP.KVEF.FF.W.0087.000000T0000Z-180730T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
628 PM PDT SUN JUL 29 2018

...THE FLASH FLOOD WARNING FOR CENTRAL CLARK COUNTY WILL EXPIRE AT
630 PM PDT...

Washes will continue to be running for the next few hours. Runoff 
and ponding of water from the earlier heavy rain will continue to 
cause minor flooding issues. Flash flooding is no longer expected to 
pose a threat. Please continue to heed any remaining road closures.

LAT...LON 3605 11527 3597 11521 3589 11537 3599 11545
      3611 11548 3611 11534

$$

SC

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 2:39 PM PDTAreal Flood AdvisoryVEFClark2 hr
Jul 29, 2:51 PM PDTAreal Flood AdvisoryVEFClark39 min
Jul 29, 2:55 PM PDTSevere Thunderstorm WarningVEFClark50 min
Jul 29, 3:02 PM PDTFlash Flood WarningVEFClark3 hr

Nearby

Flash Flood Warnings in Nevada, 2018Every flash flood warning in 2018

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.