Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 13, NWS San Diego, CA

August 12, 2012San Diego County, California

NWS San Diego, CA issued this flash flood warning at Aug 12, 2012, 2:55 PM PDT for San Diego County, California. It was in force for 2 hr. 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 12, 2012, 2:55 PM PDT (21:55 UTC)
Expired
Aug 12, 2012, 5:11 PM PDT
In force
2 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Diego County, CA

The radar

The San Diego radar (KNKX), 50 km from the middle of the area, began a volume at 21:56 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, 9.9 hours before the alert went out and 70 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 2012-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 552 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 2012-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -9 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
552 J/kg
Mixed-layer CIN
-580 J/kg
Mixed-layer LCL
1680 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
-9 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.

261 
WGUS56 KSGX 122155
FFWSGX
CAC073-130045-
/O.NEW.KSGX.FF.W.0013.120812T2155Z-120813T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
255 PM PDT SUN AUG 12 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 545 PM PDT

* AT 242 PM PDT...LOCAL LAW ENFORCEMENT OFFICIALS REPORTED FLASH     
  FLOODING FROM A STORM OVER THE WARNED AREA. FLOODING...THREE FEET  
  OF WATER...HAS BEEN REPORTED ON ROUTE 79 AND SAN FELIPE ROAD SOUTH 
  OF WARNER SPRINGS. MONTEZUMA VALLEY ROAD WILL BE IMPACTED          
  AS WELL AS THE BUENA VISTA CREEK.   

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

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.

&&

LAT...LON 3334 11682 3333 11652 3316 11652 3316 11681

$$

JT/JTT
2 follow-up statements
242 
WGUS76 KSGX 122246
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
346 PM PDT SUN AUG 12 2012

CAC073-130045-
/O.CON.KSGX.FF.W.0013.000000T0000Z-120813T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
346 PM PDT SUN AUG 12 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 545 PM PDT FOR NORTH
CENTRAL SAN DIEGO COUNTY...

AT 339 PM PDT...THUNDERSTORMS OVER THE WARNED AREA HAVE DISSIPATED. 
HOWEVER...FLASH FLOODING IS STILL POSSIBLE DOWNSTREAM OF AREAS WHICH 
RECEIVED HEAVY RAINFALL. LOCAL LAW ENFORCEMENT OFFICIALS REPORTED 
THREE FEET OF WATER AND MUD ON ROUTE 79 AND SAN FELIPE ROAD SOUTH OF 
WARNER SPRINGS AROUND 232 PM PDT. MONTEZUMA VALLEY ROAD IS EXPECTED 
TO BE IMPACTED...AS WELL AS THE BUENA VISTA CREEK. 

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO WARNER 
SPRINGS...AND LAKE HENSHAW.

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.

TO REPORT FLOODING...HAVE THE NEAREST LAW ENFORCEMENT AGENCY RELAY
YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN SAN
DIEGO.

&&

LAT...LON 3334 11682 3333 11652 3316 11652 3316 11681

$$

JJT/JT
284 
WGUS76 KSGX 130011
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
511 PM PDT SUN AUG 12 2012

CAC073-130017-
/O.CAN.KSGX.FF.W.0013.000000T0000Z-120813T0045Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN DIEGO CA-
511 PM PDT SUN AUG 12 2012

...THE FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTH CENTRAL SAN
DIEGO COUNTY...

FLOODING IS NO LONGER EXPECTED FOR THE WARNED AREA. THEREFORE...THE 
FLASH FLOOD WARNING HAS BEEN CANCELLED FOR NORTH CENTRAL SAN DIEGO 
COUNTY. MINIMAL ADDITIONAL RAINFALL IS EXPECTED OVER THE NEXT FEW 
HOURS.

LAT...LON 3334 11682 3333 11652 3316 11652 3316 11681

$$

JJT/JT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 3:02 AM PDTExcessive Heat WarningSGXRiverside, San Diego64 hr
Aug 12, 9:18 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego12 hr
Aug 12, 12:52 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino85 min
Aug 12, 1:21 PM PDTAreal Flood AdvisorySGXSan Diego77 min
Aug 12, 1:56 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 12, 2:13 PM PDTAreal Flood AdvisorySGXSan Diego77 min
Aug 12, 2:25 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 12, 3:03 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 12, 3:48 PM PDTSevere Thunderstorm WarningSGXRiverside27 min
Aug 12, 4:15 PM PDTSevere Thunderstorm WarningSGXRiverside45 min
Aug 12, 4:33 PM PDTTornado WarningSGXRiverside27 min

Nearby

Flash Flood Warnings in California, 2012Every 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.