Alert archive / California / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 1, NWS San Diego, CA

April 13, 2012Orange County, California

NWS San Diego, CA issued this severe thunderstorm warning at Apr 13, 2012, 1:50 PM PDT for Orange County, California. It was in force for 25 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: Apr 13, 2012, 1:50 PM PDT (20:50 UTC)
Expired: Apr 13, 2012, 2:15 PM PDT
In force: 25 min
Issued by: NWS San Diego, CA
Area: Storm-based polygon

County Orange County, CA

The radar

The Santa Ana Mts radar (KSOX), 22 km from the middle of the area, began a volume at 20:51 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, 8.8 hours before the alert went out and 131 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 3 J/kg
Mixed-layer CIN: -5 J/kg
Mixed-layer LCL: 608 m above ground
0-6 km bulk shear: 71 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 87 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.

070 
WUUS56 KSGX 132050
SVRSGX
CAC059-132130-
/O.NEW.KSGX.SV.W.0001.120413T2050Z-120413T2130Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE SAN DIEGO CA
150 PM PDT FRI APR 13 2012

THE NATIONAL WEATHER SERVICE IN SAN DIEGO HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL ORANGE COUNTY IN SOUTHWEST CALIFORNIA...
  THIS INCLUDES THE CITIES OF...YORBA LINDA...SANTA ANA...ANAHEIM...

* UNTIL 230 PM PDT

* AT 142 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED NEAR PLACENTIA...OR NEAR
  FULLERTON...AND MOVING NORTHEAST AT 35 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO VILLA
  PARK AND BREA

PRECAUTIONARY/PREPAREDNESS ACTIONS...

DOPPLER RADAR HAS INDICATED SOME WEAK ROTATION WITHIN THIS STORM.
WHILE NOT IMMEDIATELY LIKELY...A TORNADO MAY STILL DEVELOP. IF A
TORNADO IS SPOTTED...ACT QUICKLY AND MOVE TO A PLACE OF SAFETY IN A
STURDY STRUCTURE...SUCH AS A BASEMENT OR SMALL INTERIOR ROOM.

&&

LAT...LON 3394 11787 3388 11770 3373 11784 3369 11800
      3381 11797
TIME...MOT...LOC 2050Z 215DEG 29KT 3395 11782

$$
MM

1 follow-up statement

746 
WWUS56 KSGX 132115
SVSSGX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE SAN DIEGO CA
215 PM PDT FRI APR 13 2012

CAC059-132125-
/O.CAN.KSGX.SV.W.0001.000000T0000Z-120413T2130Z/
ORANGE CA-
215 PM PDT FRI APR 13 2012

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL ORANGE COUNTY IS
CANCELLED...

LAT...LON 3394 11787 3388 11770 3373 11784 3369 11800
      3381 11797
TIME...MOT...LOC 2115Z 215DEG 29KT 3411 11768

$$
MM

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 12, 11:04 PM PDT	Wind Advisory	SGX	Orange, Riverside, San Bernardino, San Diego	43 hr
Apr 13, 1:09 PM PDT	Special Marine Warning	SGX		51 min
Apr 13, 1:20 PM PDT	Special Weather Statement	SGX	Orange	55 min
Apr 13, 2:01 PM PDT	Special Marine Warning	SGX		17 min
Apr 13, 2:13 PM PDT	Special Weather Statement	SGX	Orange	62 min
Apr 13, 2:14 PM PDT	Areal Flood Advisory	SGX	Orange, Riverside, San Bernardino, San Diego	106 min
Apr 13, 2:34 PM PDT	Special Weather Statement	SGX	Orange	56 min
Apr 13, 2:45 PM PDT	Special Marine Warning	SGX		90 min
Apr 13, 3:07 PM PDT	Areal Flood Advisory	SGX	Orange, Riverside, San Bernardino, San Diego	113 min
Apr 13, 3:25 PM PDT	Special Weather Statement	SGX	Orange	5 min
Apr 13, 3:33 PM PDT	Special Weather Statement	SGX	San Diego	57 min

Nearby

Severe Thunderstorm Warnings in California, 2012 Every severe thunderstorm 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.