Alert archive / California / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 10, NWS San Diego, CA
NWS San Diego, CA issued this severe thunderstorm warning at Sep 9, 2021, 3:10 PM PDT for Riverside County, San Bernardino County, California. It was in force for 50 min. 3 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 9, 2021, 3:10 PM PDT (22:10 UTC)
- Expired
- Sep 9, 2021, 4:00 PM PDT
- In force
- 50 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
The radar
The Santa Ana Mts radar (KSOX), 56 km from the middle of the area, began a volume at 22:09 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 9, 3:20 PM PDT | TSTM WND GST 50 | 3 Sw Calimesa, CA | MESONET STATION 095SE CALIMESA (095SE) FROM CURRENT THUNDERSTORM WIND. |
| Sep 9, 3:20 PM PDT | NON-TSTM WND GST 65 | 2 Ssw Calimesa, CA | MESONET STATION SOCAL EDISON SCE038 CALIMESA (038SE) FROM THUNDERSTORM WIND. ON ROBERTS ROAD. |
| Sep 9, 3:30 PM PDT | TSTM WND GST 45 | 4 Wnw Calimesa, CA | MESONET STATION 155 SOCAL EDISON YUCAIPA CREEK FROM THUNDERSTORM WIND. |
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, 10.2 hours before the alert went out and 138 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.
- Mixed-layer CAPE
- 15 J/kg
- Mixed-layer CIN
- -787 J/kg
- Mixed-layer LCL
- 1710 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 44 m²/s²
- 0-3 km storm-relative helicity
- 112 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.1
The text
As transmitted.
884
WUUS56 KSGX 092210
SVRSGX
CAC065-071-092300-
/O.NEW.KSGX.SV.W.0010.210909T2210Z-210909T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
310 PM PDT Thu Sep 9 2021
The National Weather Service in San Diego has issued a
* Severe Thunderstorm Warning for...
San Bernardino County in southern California...
Riverside County in southern California...
* Until 400 PM PDT.
* At 309 PM PDT, a severe thunderstorm was located over Redlands,
moving northwest at 10 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
San Bernardino, Moreno Valley, Redlands, Yucaipa, Highland, western
Beaumont, Loma Linda, Mentone, Calimesa and Cherry Valley.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
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 3396 11695 3388 11705 3411 11728 3414 11720
3415 11711
TIME...MOT...LOC 2209Z 153DEG 7KT 3406 11714
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
SS2 follow-up statements
459
WWUS56 KSGX 092234
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
334 PM PDT Thu Sep 9 2021
CAC065-071-092300-
/O.CON.KSGX.SV.W.0010.000000T0000Z-210909T2300Z/
San Bernardino CA-Riverside CA-
334 PM PDT Thu Sep 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 400 PM PDT
FOR SAN BERNARDINO AND RIVERSIDE COUNTIES...
At 332 PM PDT, a severe thunderstorm was located over Highland, or
near Redlands, moving northwest at 10 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated. At 320 PM, 50 MPH winds were reported near
San Timoteo Canyon. Pea size hail was reported in Yucaipa.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
San Bernardino, Moreno Valley, Redlands, Yucaipa, Highland, Loma
Linda, Mentone, Calimesa and Cherry Valley.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3399 11698 3393 11710 3411 11728 3414 11720
3415 11711
TIME...MOT...LOC 2232Z 153DEG 7KT 3410 11716
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
SS646
WWUS56 KSGX 092259
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
359 PM PDT Thu Sep 9 2021
CAC065-071-092309-
/O.EXP.KSGX.SV.W.0010.000000T0000Z-210909T2300Z/
San Bernardino CA-Riverside CA-
359 PM PDT Thu Sep 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR SAN BERNARDINO AND RIVERSIDE
COUNTIES WILL EXPIRE AT 400 PM PDT...
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 will be allowed to expire.
LAT...LON 3399 11698 3393 11710 3411 11728 3414 11720
3415 11711
TIME...MOT...LOC 2259Z 153DEG 7KT 3414 11718
$$
SSThe office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 12:40 PM PDT | Special Weather Statement | SGX | 50 min | |
| Sep 9, 1:05 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 40 min |
| Sep 9, 1:19 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 22 min |
| Sep 9, 2:12 PM PDT | Areal Flood Advisory | SGX | San Diego | 3 hr |
| Sep 9, 2:34 PM PDT | Flash Flood Warning | SGX | San Bernardino | 3 hr |
| Sep 9, 2:54 PM PDT | Severe Thunderstorm Warning | SGX | San Bernardino | 66 min |
| Sep 9, 3:25 PM PDT | Special Weather Statement | SGX | 50 min | |
| Sep 9, 3:29 PM PDT | Flash Flood Warning | SGX | Riverside, San Bernardino | 2 hr |
| Sep 9, 3:46 PM PDT | Areal Flood Advisory | SGX | Riverside | 3 hr |
| Sep 9, 4:33 PM PDT | Flash Flood Warning | SGX | Riverside | 88 min |
| Sep 9, 4:35 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Bernardino | 55 min |
Nearby
Severe Thunderstorm Warnings in California, 2021Every 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.