Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 33, NWS Las Vegas, NV

July 7, 2011San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Jul 7, 2011, 3:25 PM PDT for San Bernardino County, California. It was in force for 2 hr. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Jul 7, 2011, 3:25 PM PDT (22:25 UTC)
Expired
Jul 7, 2011, 5:30 PM PDT
In force
2 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), 150 km from the middle of the area, began a volume at 22:29 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.

What was reported inside it

TimeReportWhereRemark
Jul 7, 4:08 PM PDTFLASH FLOODTwentynine Palms, CACHP REPORTED POLE LINE ROAD FROM MELDORA TO SUNRISE FLOODED AND CLOSED. THEY ALSO REPORTED LOTS OF DEBRIS AND A SWEEPER WILL BE NEEDED FOR COUNTY ROADS.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 10.4 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 2011-07-07Temperature 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 2011-07-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -19 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
1301 m above ground
0-6 km bulk shear
12 kt
0-1 km storm-relative helicity
-19 m²/s²
0-3 km storm-relative helicity
12 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.

878 
WGUS55 KVEF 072225
FFWVEF
CAC071-080030-
/O.NEW.KVEF.FF.W.0033.110707T2225Z-110708T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
325 PM PDT THU JUL 7 2011

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 530 PM PDT.

* AT 315 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  VERY HEAVY RAIN FROM A THUNDERSTORM NEAR TWENTYNINE PALMS. THE
  STORM PRODUCING VERY HEAVY RAIN WAS NEARLY STATIONARY.

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

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.

&&

LAT...LON 3403 11599 3408 11599 3409 11603 3413 11604
      3414 11627 3435 11627 3434 11594 3404 11593

$$

JS
2 follow-up statements
435 
WGUS75 KVEF 072317
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
417 PM PDT THU JUL 7 2011

CAC071-080030-
/O.CON.KVEF.FF.W.0033.000000T0000Z-110708T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
417 PM PDT THU JUL 7 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 530 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

AT 411 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING MODERATE TO HEAVY RAIN IN THE 
TWENTY NINE PALMS AREA. THIS STORM WAS NEARLY STATIONARY.

LOCATIONS IMPACTED INCLUDE...TWENTYNINE PALMS...TWENTYNINE PALMS MCAS
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 3403 11599 3408 11599 3409 11603 3413 11604
      3414 11627 3435 11627 3434 11594 3404 11593

$$

JH
760 
WGUS75 KVEF 080022
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
522 PM PDT THU JUL 7 2011

CAC071-080031-
/O.EXP.KVEF.FF.W.0033.000000T0000Z-110708T0030Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
522 PM PDT THU JUL 7 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 530 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

RAINFALL HAD ENDED OR SIGNIFICANTLY DECREASED IN THE TWENTY NINE 
PALMS AREA AS OF 5 PM. THE THREAT OF ADDITIONAL FLOODING HAS ENDED. 

LAT...LON 3403 11599 3408 11599 3409 11603 3413 11604
      3414 11627 3435 11627 3434 11594 3404 11593

$$

JH

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 5:04 PM PDTSevere Thunderstorm WarningVEFSan Bernardino41 min
Jul 6, 5:29 PM PDTAreal Flood AdvisoryVEFInyo, San Bernardino3 hr
Jul 7, 2:36 PM PDTAreal Flood AdvisoryVEFSan Bernardino3 hr
Jul 7, 3:45 PM PDTFlash Flood WarningVEFSan Bernardino2 hr
Jul 7, 3:49 PM PDTFlash Flood WarningVEFInyo3 hr

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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.