Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 111, NWS Las Vegas, NV

August 11, 2012San Bernardino County, California

NWS Las Vegas, NV issued this flash flood warning at Aug 11, 2012, 2:49 PM PDT for San Bernardino County, California. It was in force for 116 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 11, 2012, 2:49 PM PDT (21:49 UTC)
Expired: Aug 11, 2012, 4:45 PM PDT
In force: 116 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), 123 km from the middle of the area, began a volume at 21:50 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, 9.8 hours before the alert went out and 172 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 268 J/kg
Mixed-layer CIN: -713 J/kg
Mixed-layer LCL: 1560 m above ground
0-6 km bulk shear: 12 kt
0-1 km storm-relative helicity: 21 m²/s²
0-3 km storm-relative helicity: 30 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.

863 
WGUS55 KVEF 112149
FFWVEF
CAC071-112345-
/O.NEW.KVEF.FF.W.0111.120811T2149Z-120811T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE LAS VEGAS NV
249 PM PDT SAT AUG 11 2012

THE NATIONAL WEATHER SERVICE IN LAS VEGAS HAS ISSUED A

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

* UNTIL 445 PM PDT.

* AT 244 PM PDT...TRAINED WEATHER SPOTTERS REPORTED ABOUT 6 INCHES 
OF WATER FLOWING IN BUENA VISTA ROAD IN YUCCA VALLEY FROM A 
THUNDERSTORM 6 MILES NORTHWEST OF JOSHUA TREE...OR 20 MILES WEST OF 
TWENTYNINE PALMS...MOVING NORTHWEST AT 5 MPH.

* LOCATIONS IMPACTED INCLUDE...YUCCA MESA...YUCCA VALLEY AND LANDERS.
  

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 3412 11641 3418 11646 3426 11644 3427 11643
      3426 11626 3409 11626

$$

PIERCE

3 follow-up statements

149 
WGUS75 KVEF 112228
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
328 PM PDT SAT AUG 11 2012

CAC071-112345-
/O.CON.KVEF.FF.W.0111.000000T0000Z-120811T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
328 PM PDT SAT AUG 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

AT 322 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE THUNDERSTORMS THAT COULD MOVE INTO THE WARNED AREA DURING 
THE NEXT HOUR. THUNDERSTORMS PRODUCING HEAVY RAIN WERE LOCATED OVER 
THE NORTHERN SECTION OF JOSHUA TREE NATIONAL PARK. THESE STORMS WERE 
LOCATED 8 MILES SOUTHEAST OF JOSHUA TREE...OR 10 MILES SOUTHWEST OF 
TWENTYNINE PALMS...MOVING NORTHWEST AT 10 MPH TOWARD YUCCA VALLEY.

LOCATIONS IMPACTED INCLUDE...YUCCA VALLEY...YUCCA MESA...LANDERS AND 
JOSHUA TREE.

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 3412 11641 3418 11646 3426 11644 3427 11643
      3426 11626 3409 11626

$$

PIERCE

711 
WGUS75 KVEF 112252
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
352 PM PDT SAT AUG 11 2012

CAC071-112345-
/O.CON.KVEF.FF.W.0111.000000T0000Z-120811T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
352 PM PDT SAT AUG 11 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 445 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

AT 347 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING FLASH FLOODING MOVING OUT OF 
JOSHUA TREE NATIONAL PARK AND APPROACHING THE TOWN OF JOSHUA TREE AND 
STATE ROUTE 62. THIS STORM WAS LOCATED NEAR JOSHUA TREE...OR 12 
MILES WEST OF TWENTYNINE PALMS...MOVING NORTHWEST AT 10 MPH.

LOCATIONS IMPACTED INCLUDE...JOSHUA TREE...YUCCA VALLEY...YUCCA MESA.

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 3412 11641 3418 11646 3426 11644 3427 11643
      3426 11626 3409 11626

$$

PIERCE

626 
WGUS75 KVEF 112341
FFSVEF

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE LAS VEGAS NV
441 PM PDT SAT AUG 11 2012

CAC071-112346-
/O.EXP.KVEF.FF.W.0111.000000T0000Z-120811T2345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.IO/
SAN BERNARDINO CA-
441 PM PDT SAT AUG 11 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 445 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

A THUNDERSTORM WITH HEAVY RAIN HAS REMAINED GENERALLY OVER THE 
EXTREME NORTHWEST PORTION OF JOSHUA TREE NATIONAL PARK...JUST 
SKIRTING ALONG THE MOUNTAINS TO THE SOUTH OF JOSHUA TREE AND YUCCA 
VALLEY. 

THE STORM WAS MOVING TO THE WEST AND MAY CROSS HIGHWAY 62 BETWEEN 
MORONGO VALLEY AND YUCCA VALLEY AFTER 5 PM PDT.

LAT...LON 3412 11641 3418 11646 3426 11644 3427 11643
      3426 11626 3409 11626

$$

PIERCE

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 11, 2:36 PM PDT	Areal Flood Advisory	VEF	San Bernardino	114 min
Aug 11, 4:14 PM PDT	Areal Flood Advisory	VEF	San Bernardino	98 min
Aug 11, 4:43 PM PDT	Areal Flood Advisory	VEF	Inyo	2 hr

Nearby

Flash Flood Warnings in California, 2012 Every 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.