Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 21, NWS Las Vegas, NV

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

NWS Las Vegas, NV issued this flash flood warning at Jul 19, 2017, 9:57 AM PDT for San Bernardino County, California; 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 19, 2017, 9:57 AM PDT (16:57 UTC)
Expired
Jul 19, 2017, 1:00 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), 50 km from the middle of the area, began a volume at 16:59 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, 5.0 hours before the alert went out and 94 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.

957 
WGUS55 KVEF 191657
FFWVEF
CAC071-NVC003-192000-
/O.NEW.KVEF.FF.W.0021.170719T1657Z-170719T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
957 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...
  Southern Clark County in southern Nevada...

* Until 100 PM PDT

* At 957 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...
  Cima, Mountain Pass, Nipton, Nipton Road Mile Marker 3 and Nipton
  And Ivanpah Roads.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3561 11515 3541 11502 3518 11547 3545 11572
      3573 11582 3579 11563 3553 11530

$$

Czyzyk
2 follow-up statements
115 
WGUS75 KVEF 191829
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1129 AM PDT WED JUL 19 2017

CAC071-NVC003-192000-
/O.CON.KVEF.FF.W.0021.000000T0000Z-170719T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
1129 AM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 100 PM PDT FOR
NORTH CENTRAL SAN BERNARDINO AND SOUTHERN CLARK COUNTIES...

At 1127 AM PDT, Doppler radar indicated thunderstorms continuing to 
produce heavy rain in the Mojave Preserve and Mountain Pass area. 
Radar estimated that one to two inches had fallen so far, and the 
additional heavy rain will keep flash flooding likely.

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

In hilly terrain there are hundreds of low water crossings which are
potentially dangerous in heavy rain. Do not attempt to cross flooded
roads. Find an alternate route.

&&

LAT...LON 3561 11515 3541 11502 3518 11547 3545 11572
      3573 11582 3579 11563 3553 11530

$$

Morgan
167 
WGUS75 KVEF 191952
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
1252 PM PDT WED JUL 19 2017

CAC071-NVC003-192000-
/O.EXP.KVEF.FF.W.0021.000000T0000Z-170719T2000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-Clark NV-
1252 PM PDT WED JUL 19 2017

...THE FLASH FLOOD WARNING FOR NORTH CENTRAL SAN BERNARDINO AND
SOUTHERN CLARK COUNTIES WILL EXPIRE AT 100 PM PDT...

Only light rain was falling over far southwest Clark and far 
northeast San Bernardino County. The heavy rain had ended, so the 
warning will be allowed to expire. Please continue to heed any 
remaining road closures and drive safely, as several crashes had 
been reported on Interstate 15 near Mountain Pass.

LAT...LON 3561 11515 3541 11502 3518 11547 3545 11572
      3573 11582 3579 11563 3553 11530

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 18, 6:01 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 18, 7:58 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 19, 7:53 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 19, 8:53 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 18, 5:14 PM PDTSevere Thunderstorm WarningVEFClark35 min
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

Nearby

Flash Flood Warnings in California, 2017Flash Flood Warnings in Nevada, 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.