Alert archive / California / Flash Flood Warnings in 2011

Flash Flood Warning 22, NWS San Diego, CA

August 28, 2011Riverside County, San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 28, 2011, 1:39 PM PDT for Riverside County, San Diego County, California. It was in force for 81 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 28, 2011, 1:39 PM PDT (20:39 UTC)
Expired
Aug 28, 2011, 3:00 PM PDT
In force
81 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), 70 km from the middle of the area, began a volume at 20:40 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, 8.7 hours before the alert went out and 90 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 2011-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 19 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 2011-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -42 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
19 J/kg
Mixed-layer CIN
-740 J/kg
Mixed-layer LCL
2184 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
-42 m²/s²
0-3 km storm-relative helicity
33 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.

160 
WGUS56 KSGX 282039
FFWSGX
CAC065-073-282200-
/O.NEW.KSGX.FF.W.0022.110828T2039Z-110828T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
139 PM PDT SUN AUG 28 2011

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 300 PM PDT

* AT 124 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED 
VERY STRONG STORMS OVER THE MOUNTAINS OF NORTHERN SAN DIEGO COUNTY 
AND SOUTHERN RIVERSIDE COUNTY. THIS STORM COMPLEX WILL PRODUCE VERY 
HEAVY RAIN AND DANGEROUS CLOUD TO GROUND LIGHTNING. TRAINED WEATHER 
SPOTTERS ARE ENCOURAGED TO REPORT FLOODING IN THE WARNED AREA. 

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WARNER 
SPRINGS AND ANZA.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IN ADDITION TO FLASH FLOODING...RAINFALL IS EXPECTED TO CAUSE DEBRIS 
FLOWS IN RECENT BURN AREAS ACCORDING TO THRESHOLDS PROVIDED BY THE 
USGS.

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 3347 11650 3329 11644 3311 11655 3320 11681
      3373 11676 3367 11652

$$

MOKER/SMALL
2 follow-up statements
065 
WGUS76 KSGX 282132
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
232 PM PDT SUN AUG 28 2011

CAC065-073-282200-
/O.CON.KSGX.FF.W.0022.000000T0000Z-110828T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-RIVERSIDE CA-
232 PM PDT SUN AUG 28 2011

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 300 PM PDT FOR SOUTH
CENTRAL RIVERSIDE AND NORTH CENTRAL SAN DIEGO COUNTIES...

AT 224 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A THUNDERSTORM PRODUCING HEAVY RAIN NEAR WARNER SPRINGS.

LOCATIONS IN THE WARNED AREA INCLUDE BUT ARE NOT LIMITED TO ANZA 
AND WARNER SPRINGS.

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.

&&

LAT...LON 3347 11650 3329 11644 3320 11681 3373 11676
      3367 11652

$$

MOKER/SMALL
154 
WGUS76 KSGX 282151
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
251 PM PDT SUN AUG 28 2011

CAC065-073-282201-
/O.EXP.KSGX.FF.W.0022.000000T0000Z-110828T2200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-RIVERSIDE CA-
251 PM PDT SUN AUG 28 2011

...THE FLASH FLOOD WARNING WILL EXPIRE AT 300 PM PDT FOR SOUTH
CENTRAL RIVERSIDE AND NORTH CENTRAL SAN DIEGO COUNTIES...

THE STORM HAS WEAKENED SO THE WARNING WILL BE ALLOWED TO EXPIRE.

LAT...LON 3347 11650 3329 11644 3320 11681 3373 11676
      3367 11652

$$

MOKER/SMALL

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 27, 11:30 PM PDTDust Storm WarningSGXRiverside, San Diego3 hr
Aug 28, 11:29 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego7 hr
Aug 28, 1:46 PM PDTSevere Thunderstorm WarningSGXSan Diego29 min
Aug 28, 2:14 PM PDTSevere Thunderstorm WarningSGXSan Diego31 min
Aug 28, 3:01 PM PDTFlash Flood WarningSGXSan Bernardino89 min
Aug 28, 3:11 PM PDTSevere Thunderstorm WarningSGXSan Diego34 min
Aug 28, 3:33 PM PDTFlash Flood WarningSGXSan Bernardino73 min
Aug 28, 3:47 PM PDTFlash Flood WarningSGXRiverside, San Bernardino66 min
Aug 28, 4:32 PM PDTAreal Flood AdvisorySGXSan Bernardino79 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.