Alert archive / California / Flash Flood Warnings in 2012

Flash Flood Warning 22, NWS San Diego, CA

August 17, 2012Riverside County, California

NWS San Diego, CA issued this flash flood warning at Aug 17, 2012, 12:14 PM PDT for Riverside County, California. It was in force for 61 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 17, 2012, 12:14 PM PDT (19:14 UTC)
Expired
Aug 17, 2012, 1:15 PM PDT
In force
61 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Flood severity
None

County Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 79 km from the middle of the area, began a volume at 19:14 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, 7.2 hours before the alert went out and 102 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 2012-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 139 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, San Diego, CA at 12:00Z on 2012-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
139 J/kg
Mixed-layer CIN
-312 J/kg
Mixed-layer LCL
1655 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
29 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.

171 
WGUS56 KSGX 171914
FFWSGX
CAC065-172015-
/O.NEW.KSGX.FF.W.0022.120817T1914Z-120817T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
1214 PM PDT FRI AUG 17 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* FLASH FLOOD WARNING FOR...
  WEST CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 115 PM PDT

* AT 1207 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  FLASH FLOODING FROM A STORM OVER THE WARNED AREA.

* LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO LAKE 
HEMET. PORTIONS OF THE BUCK FIRE BURN SCAR MAY BE INCLUDED.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

EXCESSIVE RUNOFF FROM HEAVY RAINFALL WILL CAUSE FLOODING OF SMALL
CREEKS AND STREAMS...COUNTRY ROADS...AS WELL AS FARMLAND ALONG THE
BANKS OF CREEKS AND STREAMS.

&&

LAT...LON 3371 11684 3369 11671 3361 11670 3360 11680
      3360 11693

$$

MM
2 follow-up statements
878 
WGUS76 KSGX 171942
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
1242 PM PDT FRI AUG 17 2012

CAC065-172015-
/O.CON.KSGX.FF.W.0022.000000T0000Z-120817T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
1242 PM PDT FRI AUG 17 2012

...A FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 115 PM PDT FOR WEST
CENTRAL RIVERSIDE COUNTY...

AT 1234 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO
INDICATE HEAVY RAIN PRODUCING FLASH FLOODING OVER THE WARNED AREA.

THIS THUNDERSTORM WITH EXCESSIVE RAIN WILL OTHERWISE REMAIN OVER 
MAINLY RURAL AREAS OF THE INDICATED COUNTY. PORTIONS OF THE BUCK 
FIRE SCAR MAY BE INCLUDED.

LAT...LON 3371 11684 3369 11671 3361 11670 3360 11680
      3360 11693

$$

MM
324 
WGUS76 KSGX 172020
FFSSGX

FLASH FLOOD STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
120 PM PDT FRI AUG 17 2012

CAC065-172029-
/O.EXP.KSGX.FF.W.0022.000000T0000Z-120817T2015Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
RIVERSIDE CA-
120 PM PDT FRI AUG 17 2012

...THE FLASH FLOOD WARNING HAS EXPIRED FOR WEST CENTRAL RIVERSIDE
COUNTY...

THE RAINFALL LEADING TO THE FLASH FLOODING AROUND LAKE HEMET AND 
SAGE HAS DECREASED AND THE FLASH FLOOD WARNING IS ALLOWED TO EXPIRE.


LAT...LON 3371 11684 3369 11671 3361 11670 3360 11680
      3360 11693

$$

MM

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 16, 7:07 PM PDTFlash Flood WatchSGXRiverside, San Bernardino, San Diego25 hr
Aug 17, 12:28 PM PDTFlash Flood WarningSGXRiverside, San Diego2 hr
Aug 17, 12:55 PM PDTSevere Thunderstorm WarningSGXRiverside50 min
Aug 17, 1:07 PM PDTFlash Flood WarningSGXRiverside, San Bernardino3 hr
Aug 17, 1:39 PM PDTSevere Thunderstorm WarningSGXSan Diego51 min
Aug 17, 1:40 PM PDTFlash Flood WarningSGXSan Diego95 min
Aug 17, 2:19 PM PDTFlash Flood WarningSGXRiverside46 min
Aug 17, 3:19 PM PDTAreal Flood AdvisorySGXSan Bernardino86 min
Aug 17, 4:47 PM PDTAreal Flood AdvisorySGXSan Bernardino75 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.