Alert archive / California / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 7, NWS San Diego, CA
NWS San Diego, CA issued this severe thunderstorm warning at Sep 9, 2021, 1:05 PM PDT for San Bernardino County, California. It was in force for 40 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 9, 2021, 1:05 PM PDT (20:05 UTC)
- Expired
- Sep 9, 2021, 1:45 PM PDT
- In force
- 40 min
- Issued by
- NWS San Diego, CA
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
County San Bernardino County, CA
The radar
The Edwards AFB radar (KEYX), 116 km from the middle of the area, began a volume at 20:07 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, 1:26 PM PDT | TSTM WND GST 46 | 20 Ene Big Bear City, CA | MESONET STATION MNLC1 MEANS LAKE. THUNDERSTORM WIND OUTFLOW. TEMPERATURE WENT FROM 98 TO 77F. |
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, 8.1 hours before the alert went out and 200 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.
120
WUUS56 KSGX 092005
SVRSGX
CAC071-092045-
/O.NEW.KSGX.SV.W.0007.210909T2005Z-210909T2045Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
105 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 145 PM PDT.
* At 104 PM PDT, a severe thunderstorm was located over northeastern
Johnson Valley, or 17 miles northeast of Onyx Summit, moving
northwest at 20 mph.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Johnson Valley.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3473 11654 3464 11650 3461 11651 3460 11649
3439 11640 3436 11641 3432 11648 3430 11647
3426 11657 3461 11683
TIME...MOT...LOC 2004Z 154DEG 19KT 3438 11652
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
JMB1 follow-up statement
640
WWUS56 KSGX 092044
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
144 PM PDT Thu Sep 9 2021
CAC071-092052-
/O.EXP.KSGX.SV.W.0007.000000T0000Z-210909T2045Z/
San Bernardino CA-
144 PM PDT Thu Sep 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR SAN BERNARDINO COUNTY WILL
EXPIRE AT 145 PM PDT...
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire. However heavy
rain is still possible with this thunderstorm and could cause
localized flooding.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
San Diego.
LAT...LON 3473 11654 3464 11650 3461 11651 3460 11649
3439 11640 3436 11641 3432 11648 3430 11647
3426 11657 3461 11683
TIME...MOT...LOC 2042Z 154DEG 19KT 3453 11661
$$
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, 1:19 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, 3:10 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.