Alert archive / California / Flash Flood Warnings in 2017

Flash Flood Warning 73, NWS Las Vegas, NV

August 3, 2017San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 3, 2017, 2:00 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
Aug 3, 2017, 2:00 PM PDT (21:00 UTC)
Expired
Aug 3, 2017, 5:00 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 Santa Ana Mts radar (KSOX), 118 km from the middle of the area, began a volume at 21:03 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, 9.0 hours before the alert went out and 168 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 2017-08-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 527 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, San Diego, CA at 12:00Z on 2017-08-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -10 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
527 J/kg
Mixed-layer CIN
-342 J/kg
Mixed-layer LCL
1297 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-10 m²/s²
0-3 km storm-relative helicity
1 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

911 
WGUS55 KVEF 032100
FFWVEF
CAC071-040000-
/O.NEW.KVEF.FF.W.0073.170803T2100Z-170804T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
Flash Flood Warning
National Weather Service Las Vegas NV
200 PM PDT THU AUG 3 2017

The National Weather Service in Las Vegas has issued a

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

* Until 500 PM PDT

* At 159 PM 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...
  Yucca Valley, Joshua Tree Lake Campground, Joshua Tree and Morongo
  Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3410 11660 3414 11647 3421 11644 3426 11644
      3432 11648 3435 11642 3433 11624 3412 11620
      3412 11626 3408 11627 3408 11644 3403 11648
      3403 11661

$$

ASG
2 follow-up statements
722 
WGUS75 KVEF 032234
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
334 PM PDT THU AUG 3 2017

CAC071-040000-
/O.CON.KVEF.FF.W.0073.000000T0000Z-170804T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
334 PM PDT THU AUG 3 2017

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 500 PM PDT FOR
SOUTH CENTRAL SAN BERNARDINO COUNTY...

At 332 PM PDT, Doppler radar indicated thunderstorms west of Morongo 
Valley approaching the area. This additional heavy rain will likely 
cause additional flooding across the warned area through 500 pm. 

Some locations that will experience flooding include...
Yucca Valley, Joshua Tree Lake Campground, Joshua Tree and Morongo
Valley.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3410 11660 3414 11647 3421 11644 3426 11644
      3432 11648 3435 11642 3433 11624 3412 11620
      3412 11626 3408 11627 3408 11644 3403 11648
      3403 11661

$$

ASG
138 
WGUS75 KVEF 032356
FFSVEF

Flash Flood Statement
National Weather Service Las Vegas NV
456 PM PDT THU AUG 3 2017

CAC071-040006-
/O.EXP.KVEF.FF.W.0073.000000T0000Z-170804T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
San Bernardino CA-
456 PM PDT THU AUG 3 2017

...THE FLASH FLOOD WARNING FOR SOUTH CENTRAL SAN BERNARDINO COUNTY
WILL EXPIRE AT 500 PM PDT...

The heavy rain has ended. Flooding is no longer expected to pose a
threat. Please continue to heed any remaining road closures.

LAT...LON 3410 11660 3414 11647 3421 11644 3426 11644
      3432 11648 3435 11642 3433 11624 3412 11620
      3412 11626 3408 11627 3408 11644 3403 11648
      3403 11661

$$

ASG

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 2, 5:53 PM PDTFlash Flood WarningVEFInyo2 hr
Aug 2, 7:19 PM PDTSevere Thunderstorm WarningVEFSan Bernardino26 min
Aug 2, 7:36 PM PDTFlash Flood WarningVEFInyo3 hr
Aug 2, 8:09 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 2, 8:19 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 2, 8:57 PM PDTAreal Flood AdvisoryVEFInyo3 hr
Aug 2, 9:54 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 2, 10:04 PM PDTFlash Flood WarningVEFInyo, San Bernardino3 hr
Aug 2, 11:36 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Aug 3, 2:27 AM PDTFlash Flood WatchVEFInyo, San Bernardino21 hr
Aug 3, 6:02 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 3, 7:41 AM PDTFlash Flood WarningVEFSan Bernardino3 hr
Aug 3, 8:59 AM 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.