Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 69, NWS Las Vegas, NV

August 1, 2011San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 1, 2011, 3:47 PM PDT for San Bernardino County, California. It was in force for 67 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
Aug 1, 2011, 3:47 PM PDT (22:47 UTC)
Expired
Aug 1, 2011, 4:54 PM PDT
In force
67 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), 146 km from the middle of the area, began a volume at 22:48 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, 10.8 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 2011-08-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 80 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 2011-08-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 34 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
80 J/kg
Mixed-layer CIN
-587 J/kg
Mixed-layer LCL
938 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
34 m²/s²
0-3 km storm-relative helicity
94 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.

920 
WGUS55 KVEF 012247
FFWVEF
CAC071-020045-
/O.NEW.KVEF.FF.W.0069.110801T2247Z-110802T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
347 PM PDT MON AUG 1 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  SOUTH CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 545 PM PDT.

* AT 345 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR WEST WIND AERO...OR 6   
  MILES SOUTHEAST OF TWENTYNINE PALMS...MOVING NORTH AT 5 MPH. 
  ANOTHER STORM WITH HEAVY RAIN WAS EXPANDING FROM JOHNSON VALLEY 
  TOWARD JOSHUA TREE.

* LOCATIONS IMPACTED INCLUDE...TWENTYNINE PALMS...TWENTYNINE PALMS
  MCAS...WEST WIND AERO AND JOSHUA TREE LAKE CAMPGROUND.

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3404 11600 3408 11600 3408 11603 3412 11606
      3412 11614 3431 11645 3434 11645 3436 11641
      3454 11642 3423 11567 3402 11587 3403 11598

$$

JA
2 follow-up statements
799 
WGUS75 KVEF 012302
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
402 PM PDT MON AUG 1 2011

CAC071-020045-
/O.CON.KVEF.FF.W.0069.000000T0000Z-110802T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
402 PM PDT MON AUG 1 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

AT 354 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS PRODUCING VERY HEAVY RAIN.  ONE STORM WAS 
LOCATED NEAR WEST WIND AERO...OR 9 MILES SOUTHEAST OF TWENTYNINE 
PALMS...MOVING NORTHEAST AT 10 TO 15 MPH. THE OTHER STORM WAS 
BETWEEN JOSHUA TREE AND JOHNSON VALLEY...TO THE NORTHEAST OF STATE 
ROUTE 247. THESE STORMS ARE CAPABLE OF PRODUCING OVER AN INCH OF 
RAIN IN 30 MINUTES WHICH WILL RESULT IN FLASH FLOODING ALONG STATE 
ROUTE 62 AND SECONDARY ROADS IN THE WARNING AREA.

LOCATIONS IMPACTED INCLUDE...TWENTYNINE PALMS...TWENTYNINE PALMS 
CORPS AIR STATION...AND SECTIONS OF STATE ROUTE 62 EAST OF 
TWENTYNINE PALMS TO AROUND MILE MARKER 50.

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 TWITTER #NWSVEGAS.

&&

LAT...LON 3404 11600 3408 11600 3408 11603 3412 11606
      3412 11614 3431 11645 3434 11645 3436 11641
      3454 11642 3423 11567 3402 11587 3403 11598

$$

JA
471 
WGUS75 KVEF 012354
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
454 PM PDT MON AUG 1 2011

CAC071-020000-
/O.CAN.KVEF.FF.W.0069.000000T0000Z-110802T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
454 PM PDT MON AUG 1 2011

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

THUNDERSTORMS HAVE MOVED AWAY FROM THE AREA AROUND TWENTYNINE PALMS 
AND NEARBY SECTIONS OF STATE ROUTE 62 AND THE HEAVY RAIN SHOWERS 
ENDED SHORTLY AFTER 4 PM PDT. DUE TO THE BRIEF PERIOD OF HEAVY 
RAIN...THE THREAT OF SIGNIFICANT FLOODING HAS ENDED.

LAT...LON 3404 11600 3408 11600 3408 11603 3412 11606
      3412 11614 3431 11645 3434 11645 3436 11641
      3454 11642 3423 11567 3402 11587 3403 11598

$$

JA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 1, 4:43 PM PDTFlash Flood WarningVEFInyo2 hr
Aug 1, 4:45 PM PDTSevere Thunderstorm WarningVEFSan Bernardino45 min

Nearby

Flash Flood Warnings in California, 2011Every flash flood warning in 2011

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.