Alert archive / California / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 9, NWS San Diego, CA
NWS San Diego, CA issued this severe thunderstorm warning at Sep 9, 2021, 2:54 PM PDT for San Bernardino County, California. It was in force for 66 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
- Sep 9, 2021, 2:54 PM PDT (21:54 UTC)
- Expired
- Sep 9, 2021, 4:00 PM PDT
- In force
- 66 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Hail
- 1.0 in
- Wind
- 60.0 mph
County San Bernardino County, CA
The radar
The Santa Ana Mts radar (KSOX), 77 km from the middle of the area, began a volume at 21:57 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, 9.9 hours before the alert went out and 171 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.
427
WUUS56 KSGX 092154
SVRSGX
CAC071-092300-
/O.NEW.KSGX.SV.W.0009.210909T2154Z-210909T2300Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
254 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...
* Until 400 PM PDT.
* At 253 PM PDT, a severe thunderstorm was located over Hwy 18
Between Running Springs And Big Bear, or 8 miles east of Lake
Arrowhead, moving northwest at 10 mph.
HAZARD...60 mph wind gusts and quarter size hail.
SOURCE...Radar indicated.
IMPACT...Hail damage to vehicles is expected. Expect wind damage
to roofs, siding, and trees.
* Locations impacted include...
Hesperia, Apple Valley, Lake Arrowhead, Lucerne Valley, Big Bear
Lake, Running Springs, Hwy 18 Between Running Springs And
Skyforest, Hwy 18 Between Running Springs And Big Bear, Hwy 173
Between Lake Arrowhead And Hesperia and Green Valley Lake.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3427 11690 3416 11707 3440 11737 3457 11712
TIME...MOT...LOC 2153Z 141DEG 10KT 3427 11704
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JMB1 follow-up statement
893
WWUS56 KSGX 092301
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
401 PM PDT Thu Sep 9 2021
CAC071-092311-
/O.EXP.KSGX.SV.W.0009.000000T0000Z-210909T2300Z/
San Bernardino CA-
401 PM PDT Thu Sep 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR SAN BERNARDINO COUNTY HAS
EXPIRED...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been allowed to expire.
LAT...LON 3427 11690 3416 11707 3440 11737 3457 11712
TIME...MOT...LOC 2301Z 135DEG 8KT 3439 11717
$$
JMBThe 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, 3:10 PM PDT | Severe Thunderstorm Warning | SGX | Riverside, San Bernardino | 50 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.