Alert archive / California / Severe Thunderstorm Warnings in 2026

Severe Thunderstorm Warning 7, NWS San Diego, CA

September 8, 2026Riverside County, San Diego County, California

NWS San Diego, CA issued this severe thunderstorm warning at Sep 8, 2026, 5:08 PM PDT for Riverside County, San Diego County, California. It was in force for 35 min. 2 reports 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 8, 2026, 5:08 PM PDT (00:08 UTC)
Expired
Sep 8, 2026, 5:43 PM PDT
In force
35 min
Issued by
NWS San Diego, CA
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Riverside County, CA, San Diego County, CA

The radar

The Santa Ana Mts radar (KSOX), 62 km from the middle of the area, began a volume at 00:11 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

TimeReportWhereRemark
Sep 8, 5:10 PM PDTTSTM WND GST 654 Ene Rainbow, CA
Sep 8, 5:20 PM PDTTSTM WND GST 614 Ene Rainbow, CA

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this severe thunderstorm warning; the first came 2 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 0.1 hours before the alert went out and 79 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 00:00Z on 2026-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 17 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 00:00Z on 2026-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -28 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
17 J/kg
Mixed-layer CIN
-404 J/kg
Mixed-layer LCL
1965 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
-28 m²/s²
0-3 km storm-relative helicity
-3 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

867 
WUUS56 KSGX 090008
SVRSGX
CAC065-073-090115-
/O.NEW.KSGX.SV.W.0007.260909T0008Z-260909T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
508 PM PDT Tue Sep 8 2026

The National Weather Service in San Diego has issued a

* Severe Thunderstorm Warning for...
  Riverside County in southern California...
  North central San Diego County in southwestern California...

* Until 615 PM PDT.

* At 507 PM PDT, a severe thunderstorm was located near Temecula,
  moving northwest at 15 mph.

  HAZARD...60 mph wind gusts and hail up to half an inch.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Temecula, Lake Elsinore, Fallbrook, Murrieta, Menifee, Sun City,
  Aguanga, Wildomar, Pechanga Indian Reservation, Santa Rosa Plateau,
  Pala Indian Reservation, Lake Skinner Recreation Area, Rainbow,
  Sedco Hills, Winchester, and Pauma Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3344 11693 3335 11705 3355 11737 3373 11715
TIME...MOT...LOC 0007Z 138DEG 12KT 3347 11709 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

PS
2 follow-up statements
468 
WWUS56 KSGX 090022
SVSSGX

Severe Weather Statement
National Weather Service San Diego CA
522 PM PDT Tue Sep 8 2026

CAC065-073-090115-
/O.CON.KSGX.SV.W.0007.000000T0000Z-260909T0115Z/
Riverside CA-San Diego CA-
522 PM PDT Tue Sep 8 2026

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM PDT
FOR RIVERSIDE AND NORTH CENTRAL SAN DIEGO COUNTIES...

At 519 PM PDT, a severe thunderstorm was located over Temecula, and
is nearly stationary.

HAZARD...70 mph wind gusts.

SOURCE...Wind report confirmed 65 mph wind gust near Temecula.

IMPACT...Expect considerable tree damage. Damage is likely to mobile 
         homes, roofs, and outbuildings.

Locations impacted include...
Temecula, Lake Elsinore, Fallbrook, Murrieta, Menifee, Sun City,
Aguanga, Wildomar, Pechanga Indian Reservation, Santa Rosa Plateau,
Pala Indian Reservation, Lake Skinner Recreation Area, Rainbow, Sedco
Hills, Winchester, and Pauma Indian Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3344 11693 3335 11705 3355 11737 3373 11715
TIME...MOT...LOC 0019Z 138DEG 12KT 3349 11711 

THUNDERSTORM DAMAGE THREAT...CONSIDERABLE
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...70 MPH

$$

PS
739 
WWUS56 KSGX 090043
SVSSGX

Severe Weather Statement
National Weather Service San Diego CA
543 PM PDT Tue Sep 8 2026

CAC065-073-090053-
/O.CAN.KSGX.SV.W.0007.000000T0000Z-260909T0115Z/
Riverside CA-San Diego CA-
543 PM PDT Tue Sep 8 2026

...THE SEVERE THUNDERSTORM WARNING FOR RIVERSIDE AND NORTH CENTRAL
SAN DIEGO COUNTIES 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, gusty winds and
heavy rain are still possible with this thunderstorm.

&&

LAT...LON 3344 11693 3335 11705 3355 11737 3373 11715
TIME...MOT...LOC 0036Z 138DEG 12KT 3355 11718 

$$

PS

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS San Diego, CA wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 8, 12:59 PM PDT, 4 hours 9 minutes earlier.

Area forecast discussion, Sep 8, 12:59 PM PDT, 4 hours 9 minutes before
Area Forecast Discussion
National Weather Service San Diego CA
1259 PM PDT Tue Sep 8 2026

.SYNOPSIS...
The ongoing heatwave in San Diego County will spread to
include all of Southern California from now through Thursday. A
combination of above average temperatures and high humidity will
create major to extreme heatRisk through the coastal basin.
Moderate to locally major HeatRisk expected elsewhere. A cooling
trend starting Friday will bring temperatures back to near or
slightly below normal from Sunday onward. Scattered thunderstorms
expected in the mountains this afternoon. Only a slight chance for
showers or storms Wednesday and Thursday.

&&

.DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING ORANGE...
SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN BERNARDINO
COUNTIES...

A number of factors came together to create a scorching afternoon in
San Diego County yesterday. First, the tropical moisture that has
been funneling into the region for a few days effectively wiped out
any cooling marine layer influence. Also, subsidence was likely
sourced from multiple locations yesterday; the building high
pressure to the east and the compensating sinking air associated
with the shower activity over Orange County and areas further north.

As high pressure continues to build into Southern California,
tropical clouds and showers will be pushed northward and
anomalously hot conditions will expand to include the entire
region from today through Thursday. Additionally, southeasterly
flow today and Wednesday will bring exceptionally high humidity to
the region, which will not only exacerbate the heat during the
day, but will also limit the amount of cooling expected overnight.
High and low temperatures running around 5 to 15 (locally 20)
degrees above normal along with high humidity will create major to
extreme HeatRisk throughout the coastal basin today and
Wednesday. Similarly anomalous temperatures will create moderate
HeatRisk in the mountains and deserts with areas of major HeatRisk
in the low deserts. Note that this set up will be particularly
anomalous and uncomfortable for coastal areas where the typical
marine layer influence will be weak or absent. It is advised to
seek shelter in air-conditioned buildings and stay hydrated during
this heatwave.

As flow turns more southerly today, there will be sufficient
moisture for isolated to scattered monsoon showers and thunderstorms
along the mountain ridges from San Diego County northward up through
the Big Bear Lake area. The morning sounding at KNKX recorded PWATs
around 1.8 inches, but modest CAPE values and capping will limit how
much of that moisture can be realized as precipitation. Still,
thunderstorms may locally produce rain rates over 0.5" per hour
along with gusty winds, mainly in San Diego County. As high pressure
moves overhead on Wednesday, mountain thunderstorm chances will
become quite limited (10-20%). Further capping on Thursday may
inhibit any shower or storm development entirely.

The high pressure slowly begins to weaken from Thursday onward.
Moderate to major HeatRisk is expected to linger through Thursday
across the region and into Friday for the deserts. Thereafter,
temperatures continue to cool over the weekend, returning to near or
slightly below normal from Sunday onward. Additionally, marine layer
clouds will finally return beginning on Friday or Saturday.
Increasing onshore flow will allow the marine layer to deepen into
early next week.

&&

.AVIATION...
081800Z...Mostly VFR conditions expected across the region through
the TAF period. SCT to locally BKN clouds between 10-20 kft. CBs
based at 9 kft MSL leading to isolated SHRA/TSRA over mountains with
tops to 35 kft 19-01Z. Localized gusty winds in and near any TSRA.

&&

.MARINE...
No hazardous marine conditions are expected through Saturday.

&&

.BEACHES...
A large south swell from Tropical Storm Marie will continue to
produce large surf of 3 to 6 feet, with sets up to 8 feet today,
highest on south and southwest facing beaches. This will result in
strong rip and longshore currents, creating hazardous swimming
conditions. Additionally, high tide this evening will combine with
the high surf to produce minor tidal overflow, coastal flooding, and
localized beach erosion. Swell and surf will gradually diminish
overnight tonight. Check the Coastal Hazard Message for details.

&&

.SKYWARN...
Skywarn activation is not requested. However weather spotters are
encouraged to report significant weather conditions.

&&

.SGX WATCHES/WARNINGS/ADVISORIES...
CA...Coastal Flood Advisory until 11 PM PDT this evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     High Surf Advisory until 11 PM PDT this evening for Orange
     County Coastal Areas-San Diego County Coastal Areas.

     Extreme Heat Warning until 8 PM PDT Wednesday for Orange County
     Coastal Areas-Orange County Inland Areas-San Bernardino and
     Riverside County Valleys-The Inland Empire-San Diego County
     Coastal Areas-San Diego County Valleys-Santa Ana Mountains
     and Foothills.

     Heat Advisory from 8 PM Wednesday to 8 PM PDT Thursday for
     Orange County Coastal Areas-Orange County Inland Areas-San
     Bernardino and Riverside County Valleys-The Inland Empire-
     San Diego County Coastal Areas-San Diego County Valleys-
     Santa Ana Mountains and Foothills.

     Heat Advisory until 8 PM PDT Thursday for Riverside County
     Mountains-San Diego County Mountains.

     Extreme Heat Warning from 10 AM Wednesday to 8 PM PDT Friday for
     Coachella Valley-San Diego County Deserts-San Gorgonio Pass
     near Banning.

PZ...None.

&&

PUBLIC...KW
AVIATION/MARINE/BEACHES...Westerink

In the hours before

Special weather statement, Sep 8, 3:37 PM PDT, 1 hour 31 minutes before
Special Weather Statement
National Weather Service San Diego CA
337 PM PDT Tue Sep 8 2026

CAZ050-058-082300-
San Diego County Mountains CA-San Diego County Inland Valleys CA-
337 PM PDT Tue Sep 8 2026

...A STRONG THUNDERSTORM WILL IMPACT SOUTH CENTRAL SAN DIEGO COUNTY
THROUGH 400 PM PDT...

At 336 PM PDT, Doppler radar was tracking a strong thunderstorm near
Descanso, or near Alpine, moving northwest at 10 mph.

HAZARD...Wind gusts of 50 to 55 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Alpine, Cuyamaca Rancho State Park, Descanso, Boulder Creek, Skye
Valley, Captain Grande Indian Reservation, Viejas Indian Reservation,
Japatul Valley, Guatay, and Barrett Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 3276 11653 3269 11670 3294 11680 3298 11657
TIME...MOT...LOC 2236Z 154DEG 10KT 3282 11664

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH

KW
Special weather statement, Sep 8, 3:44 PM PDT, 1 hour 24 minutes before
Special Weather Statement
National Weather Service San Diego CA
344 PM PDT Tue Sep 8 2026

CAZ050-058-082330-
San Diego County Mountains CA-San Diego County Inland Valleys CA-
344 PM PDT Tue Sep 8 2026

...STRONG THUNDERSTORMS WILL IMPACT NORTH CENTRAL SAN DIEGO COUNTY
THROUGH 430 PM PDT...

At 343 PM PDT, Doppler radar was tracking a cluster of strong
thunderstorms near S7 - East Grade Rd, or 10 miles southeast of
Valley Center. These storms were nearly stationary.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Valley Center, Escondido, Palomar Mountain, Palomar Mountain State
Park, S7 - East Grade Rd, Hwy 79 Between Warner Springs And Oak
Grove, Lake Henshaw, Hwy 79 Between Oak Grove And Aguanga, La Jolla
Indian Reservation, Pauma Valley, Oak Grove, Pauma Indian
Reservation, Rincon Indian Reservation, and Santa Ysabel Indian
Reservation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 3316 11678 3313 11690 3338 11699 3339 11673
TIME...MOT...LOC 2243Z 164DEG 2KT 3320 11685

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

PS
Special weather statement, Sep 8, 4:10 PM PDT, 58 minutes before
Special Weather Statement
National Weather Service San Diego CA
410 PM PDT Tue Sep 8 2026

CAZ050-058-090000-
San Diego County Mountains CA-San Diego County Inland Valleys CA-
410 PM PDT Tue Sep 8 2026

...A STRONG THUNDERSTORM WILL IMPACT CENTRAL SAN DIEGO COUNTY THROUGH
500 PM PDT...

At 410 PM PDT, Doppler radar was tracking a strong thunderstorm near
San Diego Country Estates, or 9 miles southwest of Julian, moving
north at 15 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Ramona, Alpine, San Diego Country Estates, Hwy 78 Between Ramona And
Santa Ysabel, Descanso, Boulder Creek, Captain Grande Indian
Reservation, Wynola, and Santa Ysabel.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

Persons in campgrounds should consider seeking sturdy shelter until
this storm passes.

&&

LAT...LON 3290 11662 3288 11675 3309 11685 3313 11662
TIME...MOT...LOC 2310Z 168DEG 13KT 3299 11673

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

PS

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 8, 5:03 PM PDTAreal Flood AdvisorySGXSan Bernardino117 min
Sep 8, 5:21 PM PDTAreal Flood AdvisorySGXRiverside114 min
Sep 8, 5:41 PM PDTAreal Flood AdvisorySGXSan Bernardino109 min
Sep 9, 1:58 PM PDTSpecial Weather StatementSGXSan Diego47 min
Sep 9, 4:58 PM PDTAreal Flood AdvisorySGXRiverside62 min

Nearby

Severe Thunderstorm Warnings in California, 2026Every severe thunderstorm warning in 2026

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.