Alert archive / Nevada / Flash Flood Warnings in 2018

Flash Flood Warning 86, NWS Las Vegas, NV

July 29, 2018Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 29, 2018, 3:02 PM PDT for Clark County, Nevada. It was in force for 3 hr. 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 29, 2018, 3:02 PM PDT (22:02 UTC)
Expired
Jul 29, 2018, 6:00 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), 40 km from the middle of the area, began a volume at 22:04 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, 10.0 hours before the alert went out and 65 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.

845 
WGUS55 KVEF 292202
FFWVEF
NVC003-300100-
/O.NEW.KVEF.FF.W.0086.180729T2202Z-180730T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

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

* Until 600 PM PDT.

* At 301 PM PDT, Doppler radar and automated rain gauges indicated
  thunderstorms producing heavy rain across the warned area. Up to
  one inch of rain has already fallen. Flash flooding is expected to
  begin shortly.

* Some locations that will experience flooding include...
  Jean and Goodsprings. 

Additional rainfall amounts of an inch are possible in the warned 
area.

This includes Interstate 15 in Nevada between mile markers 10 and 19.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3585 11522 3573 11530 3577 11545 3588 11539

$$

AB
1 follow-up statement
991 
WGUS75 KVEF 300051
FFSVEF

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

NVC003-300100-
/O.EXP.KVEF.FF.W.0086.000000T0000Z-180730T0100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
551 PM PDT SUN JUL 29 2018

...THE FLASH FLOOD WARNING FOR SOUTHWESTERN CLARK COUNTY WILL EXPIRE
AT 600 PM PDT...

Any flooding that occurred should have receded. Flooding is no 
longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3585 11522 3573 11530 3577 11545 3588 11539

$$

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, 3:28 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.