Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 18, NWS San Diego, CA

August 13, 2012San Bernardino County, California

NWS San Diego, CA issued this flash flood warning at Aug 13, 2012, 1:37 PM PDT for San Bernardino County, California. It was in force for 3 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 13, 2012, 1:37 PM PDT (20:37 UTC)
Expired
Aug 13, 2012, 4:30 PM PDT
In force
3 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County San Bernardino County, CA

The radar

The Santa Ana Mts radar (KSOX), 73 km from the middle of the area, began a volume at 20:37 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, 8.6 hours before the alert went out and 152 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 2012-08-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 446 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 2012-08-13The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
446 J/kg
Mixed-layer CIN
-661 J/kg
Mixed-layer LCL
1527 m above ground
0-6 km bulk shear
14 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
67 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.

737 
WGUS56 KSGX 132037
FFWSGX
CAC071-132330-
/O.NEW.KSGX.FF.W.0018.120813T2037Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
137 PM PDT MON AUG 13 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

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

* UNTIL 430 PM PDT

* AT 130 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
  FLASH FLOODING FROM A CLUSTER OF STORMS OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST     
  FALLS...RUNNING SPRINGS...BIG BEAR LAKE AND BIG BEAR CITY. VERY    
  HEAVY RAIN HAS ALREADY RESULTED IN FLOWING WATER ALONG THE         
  STREETS IN FOREST FALLS. 

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 3405 11712 3442 11713 3441 11667 3404 11668
      3404 11694 3404 11702

$$

TS
2 follow-up statements
363 
WGUS76 KSGX 132212
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
312 PM PDT MON AUG 13 2012

CAC071-132330-
/O.CON.KSGX.FF.W.0018.000000T0000Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
312 PM PDT MON AUG 13 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

AT 300 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE SCATTERED THUNDERSTORMS PRODUCING HEAVY RAIN OVER THE 
WARNED AREA.

LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO FOREST 
FALLS..RUNNING SPRINGS...BIG BEAR LAKE AND BIG BEAR CITY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL 
CREEKS AND STREAMS...URBAN AREAS...HIGHWAYS...STREETS AND UNDERPASSES
AS WELL AS OTHER DRAINAGE AREAS AND LOW LYING SPOTS.

DEBRIS FLOWS...INCLUDING MUD AND ROCK SLIDES...ARE POSSIBLE WITH 
THESE STORMS. MUD SLIDES AND ROCK SLIDES CAN POTENTIALLY TRAP AND 
KILL PEOPLE CAUGHT IN THEIR PATH.

&&

LAT...LON 3405 11712 3442 11713 3441 11667 3404 11668
      3404 11694 3404 11702

$$

TS
165 
WGUS76 KSGX 132324
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
424 PM PDT MON AUG 13 2012

CAC071-132334-
/O.EXP.KSGX.FF.W.0018.000000T0000Z-120813T2330Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
SAN BERNARDINO CA-
424 PM PDT MON AUG 13 2012

...THE FLASH FLOOD WARNING WILL EXPIRE AT 430 PM PDT FOR SOUTH
CENTRAL SAN BERNARDINO COUNTY...

THUNDERSTORMS OVER THE WARNED AREA HAVE DISSIPATED AND ARE NO LONGER 
CONSIDERED A FLASH FLOOD THREAT. THEREFORE...THE FLASH FLOOD WARNING 
WILL BE ALLOWED TO EXPIRE AT 430 PM.

LAT...LON 3405 11712 3442 11713 3441 11667 3404 11668
      3404 11694 3404 11702

$$

TS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 12, 5:29 PM PDTSevere Thunderstorm WarningSGXSan Diego46 min
Aug 12, 5:53 PM PDTFlash Flood WarningSGXSan Diego3 hr
Aug 12, 6:14 PM PDTSevere Thunderstorm WarningSGXSan Diego46 min
Aug 12, 7:23 PM PDTAreal Flood AdvisorySGXRiverside, San Diego112 min
Aug 13, 3:23 AM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego16 hr
Aug 13, 11:43 AM PDTSpecial Weather StatementSGX47 min
Aug 13, 11:54 AM PDTAreal Flood AdvisorySGXSan Bernardino65 min
Aug 13, 12:19 PM PDTFlash Flood WarningSGXSan Diego2 hr
Aug 13, 12:28 PM PDTSpecial Weather StatementSGXSan Diego62 min
Aug 13, 12:35 PM PDTFlash Flood WarningSGXSan Diego2 hr
Aug 13, 12:58 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino3 hr
Aug 13, 1:22 PM PDTSpecial Weather StatementSGXSan Diego53 min
Aug 13, 1:31 PM PDTFlash Flood WarningSGXRiverside, San Diego2 hr
Aug 13, 3:06 PM PDTAreal Flood AdvisorySGXRiverside, San Bernardino97 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.