Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 46, NWS Las Vegas, NV

July 25, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 25, 2017, 1:28 PM PDT for 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 25, 2017, 1:28 PM PDT (20:28 UTC)
Expired
Jul 25, 2017, 4:30 PM PDT
In force
3 hr
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

The radar

The Las Vegas radar (KESX), 86 km from the middle of the area, began a volume at 20:31 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, 8.5 hours before the alert went out and 123 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 2017-07-25Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 916 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 2017-07-25The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 149 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
916 J/kg
Mixed-layer CIN
-51 J/kg
Mixed-layer LCL
897 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
149 m²/s²
0-3 km storm-relative helicity
167 m²/s²
Significant tornado parameter
0.5
Supercell composite
3.2

Open this sounding in Storm Lab

The text

As transmitted.

475 
WGUS55 KVEF 252028
FFWVEF
CAC071-252330-
/O.NEW.KVEF.FF.W.0046.170725T2028Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
128 PM PDT TUE JUL 25 2017

The National Weather Service in Las Vegas has issued a

* Flash Flood Warning for...
  Central San Bernardino County in southern California...

* Until 430 PM PDT

* At 125 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain across northern portions of the Mojave Preserve. 
  Thunderstorms will likely develop and spread farther southwestward 
  over time.

* Some locations that will experience flooding include...
  Cima Road and Mountain Pass. Kelbaker Road is likely to experience 
  flooding in the next three hours as well with additional 
  thunderstorm activity.
  

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3526 11607 3540 11578 3548 11563 3549 11546
      3561 11539 3552 11529 3527 11555 3474 11556
      3474 11606

$$

STEELE
2 follow-up statements
299 
WGUS75 KVEF 252232
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
332 PM PDT TUE JUL 25 2017

CAC071-252330-
/O.CON.KVEF.FF.W.0046.000000T0000Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
332 PM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR
CENTRAL SAN BERNARDINO COUNTY...

At 330 PM PDT, Doppler radar indicated thunderstorms producing heavy 
rain developing near Kelso.  Flash flooding is expected to begin in 
that shortly. Flooding is likely ongoing further north near Ivanpah 
due to runoff from previous storms.

Some locations that will experience flooding include...
Kelso, Mountain Pass and Nipton And Ivanpah Roads, Kelso Cima Road, 
Cima Road, and Morningstar Mine Road. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for flooding even in locations not receiving rain.
Arroyos, streams, and rivers can become raging killer currents in a
matter of minutes, even from distant rainfall.

&&

LAT...LON 3526 11607 3540 11578 3548 11563 3549 11546
      3561 11539 3552 11529 3527 11555 3474 11556
      3474 11606

$$

STEELE
298 
WGUS75 KVEF 252308
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
408 PM PDT TUE JUL 25 2017

CAC071-252317-
/O.CAN.KVEF.FF.W.0046.000000T0000Z-170725T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
408 PM PDT TUE JUL 25 2017

...THE FLASH FLOOD WARNING FOR CENTRAL SAN BERNARDINO COUNTY IS
CANCELLED...

This warning has been replaced by a new warning valid until 7 PM. 
Heavy rain poses a threat for flooding near Kelso and Amboy, as well 
as on Highway 127 north of Baker.

LAT...LON 3526 11607 3540 11578 3548 11563 3549 11546
      3561 11539 3552 11529 3527 11555 3474 11556
      3474 11606

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 6:30 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 24, 6:54 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 24, 7:40 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 24, 11:59 PM PDTFlash Flood WatchVEFSan Bernardino20 hr
Jul 25, 11:06 AM PDTFlash Flood WarningVEFSan Bernardino6 hr
Jul 25, 11:39 AM PDTFlash Flood WarningVEFInyo3 hr
Jul 25, 4:07 PM PDTFlash Flood WarningVEFSan Bernardino3 hr

Nearby

Flash 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.