Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 12, NWS San Diego, CA

September 24, 2021San Diego County, California

NWS San Diego, CA issued this severe thunderstorm warning at Sep 24, 2021, 12:13 PM PDT for San Diego County, California. It was in force for 31 min. 1 report came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued: Sep 24, 2021, 12:13 PM PDT (19:13 UTC)
Expired: Sep 24, 2021, 12:44 PM PDT
In force: 31 min
Issued by: NWS San Diego, CA
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County San Diego County, CA

The radar

The San Diego radar (KNKX), 39 km from the middle of the area, began a volume at 19:17 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.

What was reported inside it

Time	Report	Where	Remark
Sep 24, 12:20 PM PDT	TSTM WND GST 37	7 Ene Alpine, CA	MESONET STATION DESSD DESCANSO SUB. THUNDERSTORM WIND GUST.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

San Diego, CA (KNKX), launched 12:00Z, 7.2 hours before the alert went out and 53 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 1990 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: -36 m²/s²
0-3 km storm-relative helicity: 15 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

508 
WUUS56 KSGX 241913
SVRSGX
CAC073-242015-
/O.NEW.KSGX.SV.W.0012.210924T1913Z-210924T2015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
1213 PM PDT Fri Sep 24 2021

The National Weather Service in San Diego has issued a

* Severe Thunderstorm Warning for...
  Southeastern San Diego County in southwestern California...

* Until 115 PM PDT.

* At 1210 PM PDT, a severe thunderstorm was located 5 miles west of 
  Pine Valley, moving west at 10 MPH.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Alpine, Cuyamaca Rancho State Park, I-8 Between Alpine and the 
  Sunrise Highway Exit, Pine Valley, Descanso, Boulder Creek, 
  Captain Grande Indian Reservation and Viejas Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3271 11667 3295 11683 3304 11661 3276 11640
TIME...MOT...LOC 1910Z 098DEG 36KT 3286 11672 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Maxwell

1 follow-up statement

725 
WWUS56 KSGX 241944
SVSSGX

Severe Weather Statement
National Weather Service San Diego CA
1244 PM PDT Fri Sep 24 2021

CAC073-241953-
/O.CAN.KSGX.SV.W.0012.000000T0000Z-210924T2015Z/
San Diego CA-
1244 PM PDT Fri Sep 24 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHEASTERN SAN DIEGO COUNTY
IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled. Other thunderstorms could 
develop this afternoon, however.

LAT...LON 3271 11667 3295 11683 3304 11661 3276 11640
TIME...MOT...LOC 1936Z 098DEG 36KT 3291 11711 

$$

Maxwell

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 24, 8:56 AM PDT	Flash Flood Watch	SGX	Riverside, San Diego	10 hr
Sep 24, 11:08 AM PDT	Beach Hazards Statement	SGX	Orange, San Diego	8 hr
Sep 24, 12:21 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Diego	56 min
Sep 24, 1:24 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	51 min
Sep 24, 1:28 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Diego	2 hr
Sep 24, 2:09 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Diego	3 hr
Sep 24, 2:41 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	64 min
Sep 24, 2:59 PM PDT	Special Weather Statement	SGX	San Diego	61 min
Sep 24, 3:14 PM PDT	Special Marine Warning	SGX		91 min
Sep 24, 3:20 PM PDT	Severe Thunderstorm Warning	SGX	San Diego	55 min
Sep 24, 3:47 PM PDT	Special Weather Statement	SGX	Orange	58 min
Sep 24, 3:56 PM PDT	Special Marine Warning	SGX		94 min
Sep 24, 4:40 PM PDT	Special Marine Warning	SGX		65 min

Nearby

Severe Thunderstorm Warnings in California, 2021 Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.