Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 4, NWS San Diego, CA

July 6, 2011Riverside County, San Diego County, California

NWS San Diego, CA issued this flash flood warning at Jul 6, 2011, 1:31 PM PDT for Riverside County, San Diego County, California. It was in force for 59 min. 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 6, 2011, 1:31 PM PDT (20:31 UTC)
Expired
Jul 6, 2011, 2:30 PM PDT
In force
59 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

Counties Riverside County, CA, San Diego County, CA

The radar

The San Diego radar (KNKX), 60 km from the middle of the area, began a volume at 20:33 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 6, 1:45 PM PDTHEAVY RAIN 0Warner Springs, CAREPORTS OF 1 TO 2 INCHES WATER ON ROAD BUT NO SIGNIFICANT FLOODING ON HIGHWAY 79.

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, 8.5 hours before the alert went out and 79 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 2011-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 27 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 2011-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -15 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
27 J/kg
Mixed-layer CIN
-481 J/kg
Mixed-layer LCL
924 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-15 m²/s²
0-3 km storm-relative helicity
48 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.

807 
WGUS56 KSGX 062031
FFWSGX
CAC065-073-062130-
/O.NEW.KSGX.FF.W.0004.110706T2031Z-110706T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
131 PM PDT WED JUL 6 2011

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  EXTREME SOUTH CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...
  NORTH CENTRAL SAN DIEGO COUNTY IN SOUTHWEST CALIFORNIA...

* UNTIL 230 PM PDT

* AT 118 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  VERY HEAVY RAIN FROM A STORM NORTH OF WARNER SPRINGS...JUST EAST   
  OF PALOMAR MOUNTAIN AND OAK GROVE...MOVING NORTH AT 5 MPH.

* THE NEARLY STATIONARY MOVEMENT COUPLED WITH HEAVY RAIN INDICATES A 
  HIGH PROBABILITY FOR FLASH FLOODING.


PRECAUTIONARY/PREPAREDNESS ACTIONS...

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.

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

&&

LAT...LON 3346 11685 3351 11655 3325 11650 3320 11679

$$

TS
3 follow-up statements
173 
WGUS76 KSGX 062059
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
159 PM PDT WED JUL 6 2011

CAC065-073-062130-
/O.CON.KSGX.FF.W.0004.000000T0000Z-110706T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-RIVERSIDE CA-
159 PM PDT WED JUL 6 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR
EXTREME SOUTH CENTRAL RIVERSIDE AND NORTH CENTRAL SAN DIEGO
COUNTIES...

AT 156 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE STORMS PRODUCING HEAVY RAIN.  THIS STORM WAS LOCATED NEAR 
OAK GROVE...MOVING NORTH AT 5 MPH.

THESE THUNDERSTORMS ARE BEGINNING TO WEAKEN AND RECOMBINE OUTSIDE 
THE WARNED AREA...HOWEVER RUNOFF AND CONTINUED RAIN WILL KEEP THE THREAT 
FOR FLASH FLOODING. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN HILLY TERRAIN THERE ARE HUNDREDS OF LOW WATER CROSSINGS WHICH ARE
POTENTIALLY DANGEROUS IN HEAVY RAIN. DO NOT ATTEMPT TO TRAVEL ACROSS
FLOODED ROADS. FIND ALTERNATE ROUTES. IT TAKES ONLY A FEW INCHES OF
SWIFTLY FLOWING WATER TO CARRY VEHICLES AWAY.

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 3346 11685 3351 11655 3325 11650 3320 11679

$$

TS
563 
WGUS76 KSGX 062123
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
223 PM PDT WED JUL 6 2011

CAC065-073-062130-
/O.CON.KSGX.FF.W.0004.000000T0000Z-110706T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-RIVERSIDE CA-
223 PM PDT WED JUL 6 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 230 PM PDT FOR
EXTREME SOUTH CENTRAL RIVERSIDE AND NORTH CENTRAL SAN DIEGO
COUNTIES...

AT 218 PM PDT...THUNDERSTORMS HAVE WEAKENED OVER THE HIGH
TERRAIN BUT LIGHT TO MODERATE RAIN CONTINUES.

THE THREAT FOR FLASH FLOODING HAS DIMINISHED.

LAT...LON 3346 11685 3351 11655 3325 11650 3320 11679

$$

TARDY
874 
WGUS76 KSGX 062136
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
236 PM PDT WED JUL 6 2011

CAC065-073-062145-
/O.EXP.KSGX.FF.W.0004.000000T0000Z-110706T2130Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-RIVERSIDE CA-
236 PM PDT WED JUL 6 2011

...THE FLASH FLOOD WARNING HAS EXPIRED FOR EXTREME SOUTH CENTRAL
RIVERSIDE AND NORTH CENTRAL SAN DIEGO COUNTIES...

THE RAINFALL HAS DIMINISHED IN INTENSITY SINCE 130 PM. 
HOWEVER...SOME LOW LYING AREAS MAY STILL HAVE WATER OVER THE 
ROADWAYS.

LAT...LON 3346 11685 3351 11655 3325 11650 3320 11679

$$

MAXWELL

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 5, 5:12 PM PDTSevere Thunderstorm WarningSGXSan Diego48 min
Jul 6, 12:14 PM PDTSpecial Weather StatementSGXSan Diego61 min
Jul 6, 12:52 PM PDTFlash Flood WarningSGXSan Bernardino100 min
Jul 6, 12:55 PM PDTFlash Flood WarningSGXSan Diego50 min
Jul 6, 1:01 PM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego7 hr
Jul 6, 1:15 PM PDTSevere Thunderstorm WarningSGXSan Bernardino45 min
Jul 6, 1:48 PM PDTFlash Flood WarningSGXSan Bernardino87 min
Jul 6, 2:48 PM PDTSevere Thunderstorm WarningSGXRiverside42 min
Jul 6, 2:56 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino2 hr
Jul 6, 4:00 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino90 min
Jul 6, 4:27 PM PDTSpecial Weather StatementSGXSan Diego63 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; radar from the NEXRAD Level II archive.