Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 89, NWS Las Vegas, NV

August 11, 2017Clark County, Nevada; San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 11, 2017, 3:51 PM PDT for Clark County, Nevada; San Bernardino County, California. 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
Aug 11, 2017, 3:51 PM PDT (22:51 UTC)
Expired
Aug 11, 2017, 6:45 PM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

Counties San Bernardino County, CA, Clark County, NV

The radar

The Las Vegas radar (KESX), 40 km from the middle of the area, began a volume at 22:53 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.

The nearest sounding before it

Las Vegas, NV (KVEF), launched 12:00Z, 10.9 hours before the alert went out and 109 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 2017-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 285 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 2017-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
285 J/kg
Mixed-layer CIN
-224 J/kg
Mixed-layer LCL
2578 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
-38 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

015 
WGUS55 KVEF 112251
FFWVEF
CAC071-NVC003-120145-
/O.NEW.KVEF.FF.W.0089.170811T2251Z-170812T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
351 PM PDT FRI AUG 11 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  North central San Bernardino County in southern California...
  Southern Clark County in southern Nevada...

* Until 645 PM PDT

* At 349 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain near Nipton. Flash flooding is expected to begin 
  shortly. This will also affect portions of Highway 164 in Clark 
  County and Nipton Road in California. 

* Some locations that will experience flooding include...
  Nipton, Nipton And Ivanpah Roads and Nipton Road Mile Marker 3. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3557 11507 3532 11495 3516 11523 3534 11550
      3566 11536

$$

ASG
2 follow-up statements
074 
WGUS75 KVEF 120039
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
539 PM PDT FRI AUG 11 2017

CAC071-NVC003-120145-
/O.CON.KVEF.FF.W.0089.000000T0000Z-170812T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
539 PM PDT FRI AUG 11 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 645 PM PDT FOR
NORTH CENTRAL SAN BERNARDINO AND SOUTHERN CLARK COUNTIES...

At 538 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain near Nipton. Flash flooding is likely to occur in this area. A 
spotter in Nipton reported water over Nipton Road between Interstate 
15 and Nipton. 

Some locations that will experience flooding include...
Nipton, Nipton And Ivanpah Roads and Nipton Road Mile Marker 3. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3557 11507 3532 11495 3516 11523 3534 11550
      3566 11536

$$

ASG
286 
WGUS75 KVEF 120141
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
641 PM PDT FRI AUG 11 2017

CAC071-NVC003-120150-
/O.EXP.KVEF.FF.W.0089.000000T0000Z-170812T0145Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
641 PM PDT FRI AUG 11 2017

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO AND
SOUTHERN CLARK COUNTIES WILL EXPIRE AT 645 PM PDT...

The heavy rain has ended. However, standing water is likely along 
Nipton Road between Interstate 15 and Nipton. Please heed any 
remaining road closures.

LAT...LON 3557 11507 3532 11495 3516 11523 3534 11550
      3566 11536

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 12:47 PM PDTSevere Thunderstorm WarningVEFClark43 min
Aug 11, 3:00 PM PDTAreal Flood AdvisoryVEFClark3 hr
Aug 11, 3:10 PM PDTSevere Thunderstorm WarningVEFClark50 min
Aug 11, 4:32 PM PDTSevere Thunderstorm WarningVEFClark17 min
Aug 11, 1:56 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 11, 2:42 PM PDTSevere Thunderstorm WarningVEFSan Bernardino48 min
Aug 11, 2:47 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash Flood Warnings in Nevada, 2017Flash Flood Warnings in California, 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.