Alert archive / California / Flash Flood Warnings in 2015

Flash Flood Warning 2, NWS San Diego, CA

March 2, 2015Orange County, Riverside County, California

NWS San Diego, CA issued this flash flood warning at Mar 2, 2015, 11:00 AM PST for Orange County, Riverside 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
Mar 2, 2015, 11:00 AM PST (19:00 UTC)
Expired
Mar 2, 2015, 1:00 PM PST
In force
2 hr
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

Counties Orange County, CA, Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 8 km from the middle of the area, began a volume at 18:59 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, 7.0 hours before the alert went out and 112 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 2015-03-02Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 30 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 2015-03-02The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -1 square meters per square second.1939587897117136156Sfc1 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
30 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
572 m above ground
0-6 km bulk shear
77 kt
0-1 km storm-relative helicity
-1 m²/s²
0-3 km storm-relative helicity
32 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.

021 
WGUS56 KSGX 021900
FFWSGX
CAC059-065-022100-
/O.NEW.KSGX.FF.W.0002.150302T1900Z-150302T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
1100 AM PST MON MAR 2 2015

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  NORTHEASTERN ORANGE COUNTY IN SOUTHWESTERN CALIFORNIA...
  WESTERN RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 100 PM PST

* AT 1054 AM PST...DOPPLER RADAR AND AUTOMATED RAIN GAUGES INDICATED 
  THAT HEAVY RAIN WAS APPROACHING THE AREA. RAINFALL RATES OF ONE 
  HALF INCH IN 30 MINUTES HAVE BEEN OBSERVED MOVING TOWARD THE BURN 
  SCAR. FLASH FLOODING MAY BEGIN SHORTLY.

EXCESSIVE RAINFALL OVER THE BURN SCAR WILL RESULT IN DEBRIS FLOW 
MOVING THROUGH SILVERADO CANYON. THE DEBRIS FLOW CAN CONSIST OF 
ROCK...MUD...VEGETATION AND OTHER LOOSE MATERIALS.

FLASH FLOODS AND DEBRIS FLOWS ARE LIKELY TO OCCUR IN THE SILVERADO
CANYON AREA DUE TO HEAVY RAIN FALLING OVER THE SILVERADO FIRE BURN
SCAR. THIS INCLUDES HOMES AND BUSINESSES IN AND AROUND SILVERADO
CANYON ROAD. THIS IS A DANGEROUS SITUATION FOR SILVERADO CANYON
RESIDENTS...AND IMMEDIATE MEASURES SHOULD BE TAKEN TO PROTECT LIFE
AND PROPERTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

MUD SLIDES AND DEBREE FLOWS EXPECTED. TAKE APPROPRIATE ACTION.

&&

LAT...LON 3376 11757 3375 11757 3372 11763 3378 11759

$$

JT
1 follow-up statement
404 
WGUS76 KSGX 022058
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1258 PM PST MON MAR 2 2015

CAC059-022105-
/O.EXP.KSGX.FF.W.0002.000000T0000Z-150302T2100Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
ORANGE CA-
1258 PM PST MON MAR 2 2015

...THE FLASH FLOOD WARNING FOR NORTHEASTERN ORANGE COUNTY WILL EXPIRE
AT 100 PM PST...

THE HEAVY RAIN HAS ENDED OVER THE SILVERADO BURN SCAR AND FLOODING 
IS NO LONGER EXPECTED TO POSE A THREAT.

LAT...LON 3376 11757 3375 11757 3372 11763 3377 11759

$$

JT

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 1, 6:58 PM PSTSpecial Marine WarningSGX47 min
Mar 2, 4:29 AM PSTFlash Flood WarningSGXOrange3 hr
Mar 2, 7:40 AM PSTBeach Hazards StatementSGXOrange, San Diego9 hr
Mar 2, 10:28 AM PSTSpecial Weather StatementSGXOrange32 min

Nearby

Flash Flood Warnings in California, 2015Every flash flood warning in 2015

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.