Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 79, NWS Las Vegas, NV

July 31, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 31, 2012, 3:05 PM PDT for San Bernardino County, California. It was in force for 42 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 31, 2012, 3:05 PM PDT (22:05 UTC)
Expired
Jul 31, 2012, 3:47 PM PDT
In force
42 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), 151 km from the middle of the area, began a volume at 22:05 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, 10.1 hours before the alert went out and 184 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 2012-07-31Temperature 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 2012-07-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -27 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
1285 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
72 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

698 
WGUS55 KVEF 312205
FFWVEF
CAC071-010000-
/O.NEW.KVEF.FF.W.0079.120731T2205Z-120801T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
305 PM PDT TUE JUL 31 2012

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 301 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR TWENTYNINE PALMS. THE 
  STORM WAS MOVING SOUTH AT 10 MPH...AND WILL PRODUCE VERY HEAVY 
  RAIN IN THE TWENTYNINE PALMS AREA AND ON HIGHWAY 62.

* LOCATIONS IMPACTED INCLUDE...
  TWENTYNINE PALMS.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED ON AREA ROADWAYS...AROUND UNDERPASSES...
AND IN NORMALLY DRY WASHES AND LOW LYING AREAS. FLASH FLOODING IS
NATURES NUMBER ONE KILLER. NEVER TRY TO CROSS A FLOODED ROADWAY OR
WALK THROUGH FLOODWATERS. TURN AROUND...DONT DROWN!

REPORT FLOODING BY POSTING YOUR REPORT TO THE LAS VEGAS NATIONAL
WEATHER SERVICE FACEBOOK PAGE...OR BY USING THE TWITTER HASHTAG...
NWSVEGAS.

&&

LAT...LON 3411 11605 3412 11606 3412 11618 3413 11619
      3429 11619 3426 11584 3410 11584 3410 11603

$$

MORGAN
1 follow-up statement
828 
WGUS75 KVEF 312247
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
347 PM PDT TUE JUL 31 2012

CAC071-312257-
/O.CAN.KVEF.FF.W.0079.000000T0000Z-120801T0000Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
347 PM PDT TUE JUL 31 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR SOUTH CENTRAL SAN
BERNARDINO COUNTY...

AT 345 PM PDT...RADAR INDICATED THAT THE THUNDERSTORM MOVING INTO 
TWENTYNINE PALMS HAD WEAKENED RAPIDLY. THEREFORE...THE FLASH FLOOD 
WARNING HAS BEEN CANCELLED.

LAT...LON 3411 11605 3412 11606 3412 11618 3413 11619
      3429 11619 3426 11584 3410 11584 3410 11603

$$

MORGAN

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 30, 5:54 PM PDTSevere Thunderstorm WarningVEFSan Bernardino51 min
Jul 31, 2:29 AM PDTFlash Flood WatchVEFSan Bernardino19 hr
Jul 31, 10:00 AM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 31, 10:08 AM PDTFlash Flood WarningVEFSan Bernardino112 min
Jul 31, 10:38 AM PDTFlash Flood WarningVEFSan Bernardino94 min
Jul 31, 11:58 AM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 31, 12:03 PM PDTFlash Flood WarningVEFSan Bernardino3 hr
Jul 31, 1:30 PM PDTFlash Flood WarningVEFSan Bernardino49 min
Jul 31, 2:00 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 31, 3:25 PM PDTFlash Flood WarningVEFSan Bernardino65 min

Nearby

Flash Flood Warnings in California, 2012Every flash flood warning in 2012

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.