Alert archive / California / Tornado Warnings in 2012

Tornado Warning 1, NWS San Diego, CA

August 12, 2012Riverside County, California

NWS San Diego, CA issued this tornado warning at Aug 12, 2012, 4:33 PM PDT for Riverside County, California. It was in force for 27 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 12, 2012, 4:33 PM PDT (23:33 UTC)
Expired
Aug 12, 2012, 5:00 PM PDT
In force
27 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon

County Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 31 km from the middle of the area, began a volume at 23:36 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, 11.6 hours before the alert went out and 104 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.

979 
WFUS56 KSGX 122333
TORSGX
CAC065-130000-
/O.NEW.KSGX.TO.W.0001.120812T2333Z-120813T0000Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
433 PM PDT SUN AUG 12 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* TORNADO WARNING FOR...
  WEST CENTRAL RIVERSIDE COUNTY IN SOUTHERN CALIFORNIA...

* UNTIL 500 PM PDT

* AT 424 PM PDT...TRAINED WEATHER SPOTTERS REPORTED A NEARLY         
  STATIONARY TORNADO ALONG ROUTE 74...JUST WEST OF INTERSTATE 15.

* THE TORNADO WILL OTHERWISE REMAIN OVER MAINLY RURAL AREAS OF THE
  INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
STURDY SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE NEAREST
DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

THE SAFEST PLACE TO BE DURING A TORNADO IS IN A BASEMENT. GET UNDER A
WORKBENCH OR OTHER PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE...SEEK SHELTER ON THE LOWEST FLOOR OF THE BUILDING IN AN
INTERIOR HALLWAY OR ROOM SUCH AS A CLOSET. USE BLANKETS OR PILLOWS TO
COVER YOUR BODY AND ALWAYS STAY AWAY FROM WINDOWS.

IF IN MOBILE HOMES OR VEHICLES...EVACUATE THEM AND GET INSIDE A
SUBSTANTIAL SHELTER. IF NO SHELTER IS AVAILABLE...LIE FLAT IN THE
NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH YOUR HANDS.

&&

LAT...LON 3373 11744 3381 11728 3380 11724 3373 11719
      3365 11731 3363 11737
TIME...MOT...LOC 2332Z 113DEG 4KT 3377 11727

$$

JJT/JT
1 follow-up statement
731 
WWUS56 KSGX 122359
SVSSGX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
459 PM PDT SUN AUG 12 2012

CAC065-130008-
/O.EXP.KSGX.TO.W.0001.000000T0000Z-120813T0000Z/
RIVERSIDE CA-
459 PM PDT SUN AUG 12 2012

...THE TORNADO WARNING FOR WEST CENTRAL RIVERSIDE COUNTY WILL EXPIRE
AT 500 PM PDT...

THUNDERSTORMS IN THE WARNED AREA...WHICH PRODUCED A TORNADO...HAVE 
DISSIPATED. THEREFORE...THE TORNADO WARNING FOR WEST CENTRAL 
RIVERSIDE COUNTY WILL BE ALLOWED TO EXPIRE AT 500 PM PDT.

LAT...LON 3373 11744 3381 11728 3380 11724 3373 11719
      3365 11731 3363 11737
TIME...MOT...LOC 2358Z 113DEG 4KT 3378 11730

$$

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, 2:55 PM PDTFlash Flood WarningSGXSan Diego2 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

Nearby

Tornado Warnings in California, 2012Every tornado warning in 2012Tornadoes 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.