Alert archive / Nevada / Flash Flood Warnings in 2018

Flash Flood Warning 89, NWS Las Vegas, NV

July 30, 2018Clark County, Nevada

NWS Las Vegas, NV issued this flash flood warning at Jul 30, 2018, 2:16 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 30, 2018, 2:16 PM PDT (21:16 UTC)
Expired
Jul 30, 2018, 5:15 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), 93 km from the middle of the area, began a volume at 21:15 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, 9.3 hours before the alert went out and 7 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 2018-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1226 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 2018-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 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
1226 J/kg
Mixed-layer CIN
-226 J/kg
Mixed-layer LCL
2495 m above ground
0-6 km bulk shear
8 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
25 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

899 
WGUS55 KVEF 302116
FFWVEF
NVC003-310015-
/O.NEW.KVEF.FF.W.0089.180730T2116Z-180731T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
216 PM PDT MON JUL 30 2018

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  West central Clark County in southern Nevada...

* Until 515 PM PDT.

* At 215 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across the warned area. One to two inches of rain has 
  already fallen. Flash flooding is expected to begin shortly.

* Some locations that will experience flooding include...
  Rainbow Canyon, Spring Mountains, Mt. Charleston, Mahogany Grove 
  Campground, Mary Jane Falls Campground, Kyle Canyon Campground, 
  State Highway 156, State Highway 157, Dolomite Campground, 
  Fletcher View Campground, Mcwilliams Campground and Hilltop 
  Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3642 11557 3626 11539 3620 11567 3631 11571

$$

KG
2 follow-up statements
433 
WGUS75 KVEF 302238
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
338 PM PDT MON JUL 30 2018

NVC003-310015-
/O.CON.KVEF.FF.W.0089.000000T0000Z-180731T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
338 PM PDT MON JUL 30 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 515 PM PDT FOR
WEST CENTRAL CLARK COUNTY...

At 337 PM PDT, Doppler radar and automated rain gauges indicated 
thunderstorms producing heavy rain over the warned area. One to two 
inches of rain has already fallen. Flash flooding is expected to 
begin shortly.

Some locations that will experience flooding include...
Rainbow Canyon, Spring Mountains, Mt. Charleston, Mahogany Grove
Campground, Mary Jane Falls Campground, Kyle Canyon Campground,
Dolomite Campground, Fletcher View Campground, Mcwilliams Campground
and Hilltop Campground.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Flooding is occurring or is imminent. It is important to know where
you are relative to streams, rivers, or creeks which can become
killers in heavy rains. Campers and hikers should avoid streams or
creeks.

&&

LAT...LON 3642 11557 3626 11539 3620 11567 3631 11571

$$

KG
830 
WGUS75 KVEF 310006
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
506 PM PDT MON JUL 30 2018

NVC003-310015-
/O.EXP.KVEF.FF.W.0089.000000T0000Z-180731T0015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Clark NV-
506 PM PDT MON JUL 30 2018

...THE FLASH FLOOD WARNING FOR WEST CENTRAL CLARK COUNTY WILL EXPIRE
AT 515 PM PDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3642 11557 3626 11539 3620 11567 3631 11571

$$

KG

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 2:01 PM PDTAreal Flood AdvisoryVEFClark3 hr
Jul 30, 4:07 PM PDTAreal Flood AdvisoryVEFClark3 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.