Alert archive / California / Severe Thunderstorm Warnings in 2017
Severe Thunderstorm Warning 21, NWS San Diego, CA
NWS San Diego, CA issued this severe thunderstorm warning at Aug 31, 2017, 3:35 PM PDT for Riverside County, San Bernardino County, California. It was in force for 55 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
- Aug 31, 2017, 3:35 PM PDT (22:35 UTC)
- Expired
- Aug 31, 2017, 4:30 PM PDT
- In force
- 55 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), 31 km from the middle of the area, began a volume at 22:37 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, 10.6 hours before the alert went out and 136 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
- 123 J/kg
- Mixed-layer CIN
- -747 J/kg
- Mixed-layer LCL
- 2464 m above ground
- 0-6 km bulk shear
- 6 kt
- 0-1 km storm-relative helicity
- 26 m²/s²
- 0-3 km storm-relative helicity
- 35 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
573
WUUS56 KSGX 312235
SVRSGX
CAC065-071-312330-
/O.NEW.KSGX.SV.W.0021.170831T2235Z-170831T2330Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service San Diego CA
335 PM PDT THU AUG 31 2017
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 430 PM PDT
* At 333 PM PDT, nearly stationary severe thunderstorms stretched
from near Fontana south to Woodcrest.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Riverside, Fontana, Moreno Valley, Ontario, Rialto, Rancho
Cucamonga, Colton, March Airforce Base, Woodcrest, Pedley, Rubidoux
and Grand Terrace.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3395 11720 3382 11734 3394 11748 3408 11759
3416 11752 3420 11742
TIME...MOT...LOC 2233Z 137DEG 3KT 3406 11744
HAIL...0.75IN
WIND...60MPH
$$
JJT2 follow-up statements
941
WWUS56 KSGX 312310
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
410 PM PDT THU AUG 31 2017
CAC065-071-312330-
/O.CON.KSGX.SV.W.0021.000000T0000Z-170831T2330Z/
San Bernardino CA-Riverside CA-
410 PM PDT THU AUG 31 2017
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM PDT
FOR SAN BERNARDINO AND RIVERSIDE COUNTIES...
At 409 PM PDT, nearly stationary severe thunderstorms stretched from
near Fontana south to Woodcrest.
HAZARD...60 mph wind gusts and penny size hail.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Riverside, Fontana, Ontario, Rialto, Rancho Cucamonga, Colton,
Woodcrest, Pedley, Rubidoux, Grand Terrace, Glen Avon and Highgrove.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
&&
LAT...LON 3400 11726 3385 11737 3394 11748 3408 11759
3416 11752 3420 11742
TIME...MOT...LOC 2309Z 137DEG 3KT 3408 11747
HAIL...0.75IN
WIND...60MPH
$$
JJT582
WWUS56 KSGX 312328
SVSSGX
Severe Weather Statement
National Weather Service San Diego CA
428 PM PDT THU AUG 31 2017
CAC065-071-312337-
/O.EXP.KSGX.SV.W.0021.000000T0000Z-170831T2330Z/
San Bernardino CA-Riverside CA-
428 PM PDT THU AUG 31 2017
...THE SEVERE THUNDERSTORM WARNING FOR SAN BERNARDINO AND RIVERSIDE
COUNTIES WILL EXPIRE AT 430 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 gusty winds
and heavy rain are still possible with this thunderstorm.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
San Diego.
LAT...LON 3400 11726 3385 11737 3394 11748 3408 11759
3416 11752 3420 11742
TIME...MOT...LOC 2327Z 137DEG 3KT 3409 11748
$$
JJTThe office that day
Everything else NWS San Diego, CA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 31, 1:38 PM PDT | Areal Flood Advisory | SGX | San Diego | 3 hr |
| Aug 31, 2:11 PM PDT | Areal Flood Advisory | SGX | Riverside | 3 hr |
| Aug 31, 2:25 PM PDT | Severe Thunderstorm Warning | SGX | Riverside | 65 min |
| Aug 31, 3:04 PM PDT | Severe Thunderstorm Warning | SGX | Riverside | 56 min |
| Aug 31, 3:36 PM PDT | Areal Flood Advisory | SGX | Orange, Riverside, San Bernardino | 3 hr |
| Aug 31, 3:58 PM PDT | Flash Flood Warning | SGX | Riverside, San Bernardino | 3 hr |
Nearby
Severe Thunderstorm Warnings in California, 2017Every severe thunderstorm warning in 2017
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.