Alert archive / California / Severe Thunderstorm Warnings in 2021
Severe Thunderstorm Warning 104, NWS Phoenix, AZ
NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 9, 2021, 1:29 PM PDT for Riverside County, California. It was in force for 46 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, 1:29 PM PDT (20:29 UTC)
- Expired
- Sep 9, 2021, 2:15 PM PDT
- In force
- 46 min
- Issued by
- NWS Phoenix, AZ
- Area
- Storm-based polygon
- Hail
- 0.75 in
- Wind
- 60.0 mph
County Riverside County, CA
The radar
The Yuma radar (KYUX), 161 km from the middle of the area, began a volume at 20:33 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
Yuma Prvg Ground, AZ (K1Y7), launched 12:00Z, 8.5 hours before the alert went out and 174 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
- 658 J/kg
- Mixed-layer CIN
- -411 J/kg
- Mixed-layer LCL
- 2238 m above ground
- 0-6 km bulk shear
- 28 kt
- 0-1 km storm-relative helicity
- 100 m²/s²
- 0-3 km storm-relative helicity
- 132 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted.
530
WUUS55 KPSR 092029
SVRPSR
CAC065-092115-
/O.NEW.KPSR.SV.W.0104.210909T2029Z-210909T2115Z/
BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
129 PM PDT Thu Sep 9 2021
The National Weather Service in Phoenix has issued a
* Severe Thunderstorm Warning for...
Riverside County in southern California...
* Until 215 PM PDT.
* At 129 PM PDT, a severe thunderstorm was located near Chiriaco
Summit, moving northwest at 20 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
* Locations impacted include...
Chiriaco Summit and Cottonwood Visitor Center.
This includes CA Interstate 10 between mile markers 85 and 100.
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 3371 11547 3369 11548 3369 11545 3368 11544
3359 11562 3373 11587 3387 11572 3387 11558
TIME...MOT...LOC 2029Z 137DEG 16KT 3374 11564
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
INS2 follow-up statements
538
WWUS55 KPSR 092040
SVSPSR
Severe Weather Statement
National Weather Service Phoenix AZ
140 PM PDT Thu Sep 9 2021
CAC065-092115-
/O.CON.KPSR.SV.W.0104.000000T0000Z-210909T2115Z/
Riverside CA-
140 PM PDT Thu Sep 9 2021
...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM PDT
FOR RIVERSIDE COUNTY...
At 140 PM PDT, a severe thunderstorm was located near Cottonwood
Visitor Center, or 7 miles north of Chiriaco Summit, moving northwest
at 20 mph.
HAZARD...60 mph wind gusts.
SOURCE...Radar indicated.
IMPACT...Expect damage to roofs, siding, and trees.
Locations impacted include...
Chiriaco Summit and Cottonwood Visitor Center.
This includes CA Interstate 10 between mile markers 85 and 100.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
For your protection move to an interior room on the lowest floor of a
building.
Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.
&&
LAT...LON 3371 11547 3369 11548 3369 11545 3368 11544
3359 11562 3373 11587 3387 11572 3387 11558
TIME...MOT...LOC 2040Z 137DEG 16KT 3378 11568
HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH
$$
INS374
WWUS55 KPSR 092109
SVSPSR
Severe Weather Statement
National Weather Service Phoenix AZ
209 PM PDT Thu Sep 9 2021
CAC065-092117-
/O.EXP.KPSR.SV.W.0104.000000T0000Z-210909T2115Z/
Riverside CA-
209 PM PDT Thu Sep 9 2021
...THE SEVERE THUNDERSTORM WARNING FOR RIVERSIDE COUNTY WILL EXPIRE
AT 215 PM PDT...
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.
To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Phoenix.
Remember, a Severe Thunderstorm Warning still remains in effect for
portions of Joshua Tree National Park in eastern Riverside County
until 245 PM PDT.
LAT...LON 3371 11547 3369 11548 3369 11545 3368 11544
3359 11562 3373 11587 3387 11572 3387 11558
TIME...MOT...LOC 2107Z 137DEG 16KT 3386 11577
$$
INSThe office that day
Everything else NWS Phoenix, AZ issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Sep 9, 1:21 PM PDT | Special Weather Statement | PSR | Riverside | 24 min |
| Sep 9, 1:58 PM PDT | Special Weather Statement | PSR | Riverside | 32 min |
| Sep 9, 2:00 PM PDT | Severe Thunderstorm Warning | PSR | Riverside | 45 min |
| Sep 9, 2:31 PM PDT | Special Weather Statement | PSR | Riverside | 29 min |
| Sep 9, 3:42 PM PDT | Special Weather Statement | PSR | Riverside | 33 min |
| Sep 9, 4:15 PM PDT | Special Weather Statement | PSR | Riverside | 45 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.