Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 44, NWS Las Vegas, NV

July 8, 2011San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 8, 2011, 2:26 PM PDT for San Bernardino County, California. It was in force for 79 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 8, 2011, 2:26 PM PDT (21:26 UTC)
Expired
Jul 8, 2011, 3:45 PM PDT
In force
79 min
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), 65 km from the middle of the area, began a volume at 21:27 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, 9.4 hours before the alert went out and 129 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 2011-07-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 44 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 2011-07-08The 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
44 J/kg
Mixed-layer CIN
-297 J/kg
Mixed-layer LCL
2374 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-27 m²/s²
0-3 km storm-relative helicity
39 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

899 
WGUS55 KVEF 082126
FFWVEF
CAC071-082330-
/O.NEW.KVEF.FF.W.0044.110708T2126Z-110708T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
226 PM PDT FRI JUL 8 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 430 PM PDT.

* AT 217 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM OVER EAST CENTRAL SAN          
  BERNARDINO COUNTY IN THE MOJAVE NATIONAL PRESERVE...OR 12 MILES    
  EAST OF CIMA. THE STORM PRODUCING VERY HEAVY RAIN WAS NEARLY       
  STATIONARY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

FLASH FLOODING IS EXPECTED IN WASHES...LOW WATER CROSSINGS AND ON
AREA ROADWAYS. FLASH FLOODING IS NATURES NUMBER ONE KILLER. TO ESCAPE
RISING WATER...MOVE TO HIGHER GROUND. 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.

CAMPERS AND HIKERS SHOULD BE ALERT TO THE POSSIBILITY OF RAPIDLY
RISING WATER AND BE PREPARED TO MOVE QUICKLY TO HIGHER GROUND IF
FLASH FLOODING IS OBSERVED.

&&

LAT...LON 3529 11545 3535 11519 3514 11514 3508 11537

$$

JS
1 follow-up statement
926 
WGUS75 KVEF 082245
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
345 PM PDT FRI JUL 8 2011

CAC071-082250-
/O.CAN.KVEF.FF.W.0044.000000T0000Z-110708T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
345 PM PDT FRI JUL 8 2011

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

AT 340 PM...DOPPLER RADAR INDICATED THAT THUNDERSTORMS THAT PROMPTED 
THE WARNING HAVE DIMINISHED AND FLASH FLOODING IS NOT LONGER 
EXPECTED. HOWEVER...A FLOOD ADVISORY REMAINS IN EFFECT FOR THE 
MOJAVE NATIONAL PRESERVE THROUGH 415 PM. WASHES COULD REMAIN 
ELEVATED THROUGH THE REST OF THE AFTERNOON CAUSING FLOODING OF LOW 
WATER CROSSINGS ON AREA ROADWAYS.

LAT...LON 3529 11545 3535 11519 3514 11514 3508 11537

$$

JS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 7, 5:57 PM PDTFlash Flood WarningVEFInyo3 hr
Jul 7, 6:05 PM PDTAreal Flood AdvisoryVEFSan Bernardino56 min
Jul 8, 1:24 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 8, 3:10 PM PDTFlash Flood WarningVEFInyo2 hr
Jul 8, 3:32 PM PDTAreal Flood AdvisoryVEFInyo118 min
Jul 8, 3:35 PM PDTFlash Flood WarningVEFSan Bernardino66 min
Jul 8, 4:18 PM PDTAreal Flood AdvisoryVEFInyo117 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.