Alert archive / Nevada / Flash Flood Warnings in 2017

Flash Flood Warning 20, NWS Las Vegas, NV

July 19, 2017Clark County, Nevada; San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 19, 2017, 8:53 AM 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
Jul 19, 2017, 8:53 AM PDT (15:53 UTC)
Expired
Jul 19, 2017, 11:45 AM 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), 27 km from the middle of the area, began a volume at 15:56 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, 3.9 hours before the alert went out and 72 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.

530 
WGUS55 KVEF 191553
FFWVEF
CAC071-NVC003-191845-
/O.NEW.KVEF.FF.W.0020.170719T1553Z-170719T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

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

The National Weather Service in Las Vegas has issued a

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

* Until 1145 AM PDT

* At 851 AM 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...
  Interstate 15 from St. Rose to Primm, Henderson, Primm, Jean, 
  Enterprise, Paradise, Sloan, Seven Hills and Henderson Executive 
  Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3600 11511 3591 11511 3590 11491 3565 11497
      3561 11515 3553 11530 3569 11549 3596 11528

$$

Czyzyk
2 follow-up statements
201 
WGUS75 KVEF 191721
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1021 AM PDT WED JUL 19 2017

CAC071-NVC003-191845-
/O.CON.KVEF.FF.W.0020.000000T0000Z-170719T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
1021 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1145 AM PDT FOR
NORTH CENTRAL SAN BERNARDINO AND CENTRAL CLARK COUNTIES...

At 1018 AM PDT, Doppler radar indicated thunderstorms producing 
heavy rain primarily along Interstate 15 from Jean to Primm. Runoff 
and flooding from the earlier rain will continue through 1145 AM 
PDT. 

Some locations that will experience flooding include... Henderson, 
Primm, Jean, Enterprise, Paradise, Sloan, Seven Hills and Henderson 
Executive Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3600 11511 3591 11511 3590 11491 3565 11497
      3561 11515 3553 11530 3569 11549 3596 11528

$$

Czyzyk
205 
WGUS75 KVEF 191838
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1138 AM PDT WED JUL 19 2017

CAC071-NVC003-191848-
/O.EXP.KVEF.FF.W.0020.000000T0000Z-170719T1845Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
1138 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO AND
CENTRAL CLARK COUNTIES WILL EXPIRE AT 1145 AM PDT...

Only light rain was falling over southwest Clark County, so the 
warning will be allowed to expire. Please continue to heed any 
remaining road closures.

LAT...LON 3600 11511 3591 11511 3590 11491 3565 11497
      3561 11515 3553 11530 3569 11549 3596 11528

$$

Morgan

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, 6:49 AM PDTFlash Flood WarningVEFClark3 hr
Jul 19, 8:32 AM PDTFlash Flood WarningVEFClark3 hr
Jul 19, 9:57 AM PDTFlash Flood WarningVEFClark3 hr
Jul 18, 7:58 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 19, 7:53 AM 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.