Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 27, NWS San Diego, CA

September 10, 2011San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Sep 10, 2011, 6:44 PM PDT for San Bernardino County, California. It was in force for 2 hr. 2 reports 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
Sep 10, 2011, 6:44 PM PDT (01:44 UTC)
Expired
Sep 10, 2011, 8:45 PM PDT
In force
2 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

What was reported inside it

TimeReportWhereRemark
Sep 10, 7:12 PM PDTFLASH FLOODLucerne Valley, CA4 TO 5 INCHES OF STANDING WATER ON HIGHWAY 18 BETWEEN DEAD MANS POINT AND HIGHWAY 247. MULTIPLE VEHICLES STALLED DUE TO WATER INTAKE.
Sep 10, 7:20 PM PDTFLASH FLOOD2 E Apple Valley, CAHIGHWAY 18 CLOSED AT BEAR VALLEY ROAD JUST EAST OF APPLE VALLEY DUE TO 1-2 FEET OF WATER ON THE ROADWAY BETWEEN HIGH ROAD AND MILE MARKER 80. NUMEROUS VEHICLES STALLED DUE TO WATER INTAKE.

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 00:00Z, 1.7 hours before the alert went out and 191 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 00:00Z on 2011-09-11Temperature 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 00:00Z on 2011-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 65 square meters per square second.19395878Sfc1 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
972 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
65 m²/s²
0-3 km storm-relative helicity
60 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

190 
WGUS56 KSGX 110144
FFWSGX
CAC071-110345-
/O.NEW.KSGX.FF.W.0027.110911T0144Z-110911T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
644 PM PDT SAT SEP 10 2011

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL SAN BERNARDINO COUNTY IN SOUTHERN CALIFORNIA...
  THIS INCLUDES THE CITIES OF...VICTORVILLE...HESPERIA...APPLE
  VALLEY...

* UNTIL 845 PM PDT

* AT 636 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR AND LAW     
  ENFORCEMENT INDICATED FLASH FLOODING FROM A STORM OVER THE WARNED  
  AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ORO GRANDE 
  LUCERNE VALLEY...APPLE VALLEY...HESPERIA...AND VICTORVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3453 11735 3470 11733 3471 11712 3468 11687
      3434 11689 3433 11710 3435 11730

$$

SS
2 follow-up statements
702 
WGUS76 KSGX 110236
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
736 PM PDT SAT SEP 10 2011

CAC071-110345-
/O.CON.KSGX.FF.W.0027.000000T0000Z-110911T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
736 PM PDT SAT SEP 10 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 845 PM PDT FOR WEST
CENTRAL SAN BERNARDINO COUNTY...

AT 724 PM PDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED HEAVY RAIN 
PRODUCING FLASH FLOODING OVER THE WARNED AREA.

CALIFORNIA HIGHWAY PATROL REPORTED FLOODING ALONG HIGHWAY 18 IN 
LUCERNE VALLEY. THERE WAS 1-2 FEET OF WATER ON THE HIGHWAY BETWEEN 
HIGH ROAD AND MILE MARKER 80. OTHER INTERSECTIONS IN LUCERNE VALLEY 
WERE ALSO FLOODED. THERE WAS ALSO A SPOTTER REPORT OF A FLOODED HOME 
IN LUCERNE VALLEY.

WHILE THESE STORMS HAVE WEAKENED SIGNIFICANTLY...CONTINUED RAINFALL 
ON ALREADY SATURATED GROUND WILL PRODUCE ADDITIONAL RUNOFF OVER THE 
AREA...WITH WATER GRADUALLY FLOWING WEST TOWARDS APPLE 
VALLEY...HESPERIA...AND VICTORVILLE. EVEN AFTER THE RAIN 
ENDS...ROADS THAT ARE ALREADY FLOODED WILL CONTINUE TO POSE A THREAT 
TO MOTORISTS.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO 
VICTORVILLE...HESPERIA...APPLE VALLEY...AND LUCERNE VALLEY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DO NOT DRIVE YOUR VEHICLE INTO AREAS WHERE THE WATER COVERS THE
ROADWAY. THE WATER DEPTH MAY BE TOO GREAT TO ALLOW YOUR CAR TO CROSS
SAFELY. MOVE TO HIGHER GROUND.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE.

&&

LAT...LON 3453 11735 3470 11733 3471 11712 3468 11687
      3434 11689 3433 11710 3435 11730

$$

SS
328 
WGUS76 KSGX 110339
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
839 PM PDT SAT SEP 10 2011

CAC071-110348-
/O.EXP.KSGX.FF.W.0027.000000T0000Z-110911T0345Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
839 PM PDT SAT SEP 10 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 845 PM PDT FOR WEST CENTRAL
SAN BERNARDINO COUNTY...

RAINFALL IN THE AREA HAS DISSIPATED AND THE THREAT OF FLASH FLOODING 
HAS ENDED...THEREFORE THE FLASH FLOOD WARNING WILL BE ALLOWED TO 
EXPIRE AT 845 PM.

LAT...LON 3453 11735 3470 11733 3471 11712 3468 11687
      3434 11689 3433 11710 3435 11730

$$

SS

The office that day

Everything else NWS San Diego, CA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 10, 5:33 PM PDTSpecial Weather StatementSGX57 min
Sep 10, 5:37 PM PDTSpecial Weather StatementSGX83 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive.