Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 3, NWS San Diego, CA

July 25, 2021Riverside County, California

NWS San Diego, CA issued this severe thunderstorm warning at Jul 25, 2021, 4:14 PM PDT for Riverside County, California. It was in force for 36 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: Jul 25, 2021, 4:14 PM PDT (23:14 UTC)
Expired: Jul 25, 2021, 4:50 PM PDT
In force: 36 min
Issued by: NWS San Diego, CA
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

County Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 125 km from the middle of the area, began a volume at 23:14 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, 11.2 hours before the alert went out and 146 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: 1039 m above ground
0-6 km bulk shear: 22 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 54 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

077 
WUUS56 KSGX 252314
SVRSGX
CAC065-260015-
/O.NEW.KSGX.SV.W.0003.210725T2314Z-210726T0015Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
414 PM PDT Sun Jul 25 2021

The National Weather Service in San Diego has issued a

* Severe Thunderstorm Warning for...
  Riverside County in southern California...

* Until 515 PM PDT.

* At 413 PM PDT, a severe thunderstorm was located 14 miles south of
  Twentynine Palms, and is nearly stationary.

  HAZARD...60 mph wind gusts and half dollar size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Indio, Coachella, Cathedral City, Palm Desert, eastern Desert Hot
  Springs, Rancho Mirage, La Quinta, Sky Valley, Thousand Palms and
  Bermuda Dunes.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and damaging winds. People outside
should move immediately to shelter inside a strong building. Stay
away from windows.

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

&&

LAT...LON 3368 11619 3380 11644 3397 11652 3399 11645
      3395 11642 3392 11629 3392 11620 3391 11618
      3386 11613 3383 11612
TIME...MOT...LOC 2313Z 263DEG 2KT 3395 11615 

HAIL...1.25IN
WIND...60MPH
 
$$

CO

1 follow-up statement

647 
WWUS56 KSGX 252350
SVSSGX

Severe Weather Statement
National Weather Service San Diego CA
450 PM PDT Sun Jul 25 2021

CAC065-252359-
/O.CAN.KSGX.SV.W.0003.000000T0000Z-210726T0015Z/
Riverside CA-
450 PM PDT Sun Jul 25 2021

...THE SEVERE THUNDERSTORM WARNING FOR RIVERSIDE 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.  However local areas of 
heavy rain are still possible with this thunderstorm.

LAT...LON 3368 11619 3380 11644 3397 11652 3399 11645
      3395 11642 3392 11629 3392 11620 3391 11618
      3386 11613 3383 11612
TIME...MOT...LOC 2342Z 263DEG 2KT 3395 11613 

$$

CO

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 25, 3:08 PM PDT	Areal Flood Advisory	SGX	San Diego	15 min
Jul 25, 3:23 PM PDT	Flash Flood Warning Considerable damage threat	SGX	San Diego	112 min
Jul 25, 4:32 PM PDT	Areal Flood Advisory	SGX	San Diego	77 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.