Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 30, NWS Las Vegas, NV

July 24, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 24, 2017, 4:31 PM PDT for San Bernardino County, California. It was in force for 119 min. 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 24, 2017, 4:31 PM PDT (23:31 UTC)
Expired
Jul 24, 2017, 6:30 PM PDT
In force
119 min
Issued by
NWS Las Vegas, NV
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 152 km from the middle of the area, began a volume at 23:34 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

San Diego, CA (KNKX), launched 12:00Z, 11.5 hours before the alert went out and 183 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, San Diego, CA at 12:00Z on 2017-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, San Diego, CA at 12:00Z on 2017-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1776 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
7 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

177 
WGUS55 KVEF 242331
FFWVEF
CAC071-250130-
/O.NEW.KVEF.FF.W.0030.170724T2331Z-170725T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
431 PM PDT MON JUL 24 2017

The National Weather Service in Las Vegas has issued a

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

* Until 630 PM PDT

* At 430 PM PDT, Doppler radar indicated thunderstorms producing 
  heavy rain near Twentynine Palms. A spotter reported flooding at 
  Amboy Road and Utah Trail.

* Some locations that will experience flooding include...
  Twentynine Palms, Twentynine Palms Base and Twentynine Palms
  Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Excessive runoff from heavy rainfall will cause flooding of small
creeks and streams, country roads, farmland, and other low lying 
spots. If you encounter a flooded road, turn around and find another 
route.

&&

LAT...LON 3407 11600 3408 11604 3410 11604 3411 11605
      3412 11605 3412 11620 3431 11620 3431 11585
      3403 11586 3403 11600

$$

Morgan
1 follow-up statement
827 
WGUS75 KVEF 250025
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
525 PM PDT MON JUL 24 2017

CAC071-250035-
/O.CAN.KVEF.FF.W.0030.000000T0000Z-170725T0130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
525 PM PDT MON JUL 24 2017

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

Heavy rain has ended in the Twentynine Palms area, and flooding is 
no longer expected to pose a threat. Please continue to heed any 
remaining road closures.

LAT...LON 3407 11600 3408 11604 3410 11604 3411 11605
      3412 11605 3412 11620 3431 11620 3431 11585
      3403 11586 3403 11600

$$

Morgan

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 3:44 AM PDTFlash Flood WatchVEFSan Bernardino40 hr
Jul 24, 12:31 PM PDTFlash Flood WarningVEFInyo, San Bernardino4 hr
Jul 24, 2:28 PM PDTFlash Flood WarningVEFInyo3 hr
Jul 24, 4:09 PM PDTFlash Flood WarningVEFInyo, San 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.