Alert archive / California / Special Weather Statements in 2021

Special Weather Statement, NWS Phoenix, AZ

September 9, 2021Riverside County, California

NWS Phoenix, AZ issued this special weather statement at Sep 9, 2021, 1:21 PM PDT for Riverside County, California. It was in force for 24 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, 1:21 PM PDT (20:21 UTC)
Expired
Sep 9, 2021, 1:45 PM PDT
In force
24 min
Issued by
NWS Phoenix, AZ
Hail
0.00 in
Wind
50

County Riverside County, CA

The radar

The Yuma radar (KYUX), 161 km from the middle of the area, began a volume at 20:24 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, 8.4 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.

Skew-T log-pSkew-T log-p diagram, Yuma Prvg Ground, AZ at 12:00Z on 2021-09-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 658 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Yuma Prvg Ground, AZ at 12:00Z on 2021-09-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 100 square meters per square second.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
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

Open this sounding in Storm Lab

The text

As transmitted.

953 
WWUS85 KPSR 092021
SPSPSR

Special Weather Statement
National Weather Service Phoenix AZ
121 PM PDT Thu Sep 9 2021
 
CAZ560-561-564-568-092045-
Chuckwalla Mountains CA-Chiriaco Summit CA-Joshua Tree NP West CA-
Joshua Tree NP East CA-
121 PM PDT Thu Sep 9 2021

...A strong thunderstorm will impact portions of Riverside County
through 145 PM PDT...

At 121 PM PDT, Doppler radar was tracking a strong thunderstorm near
Chiriaco Summit, moving northwest at 20 mph.

HAZARD...Wind gusts up to 50 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around 
         unsecured objects.

Locations impacted include...
Chiriaco Summit and Cottonwood Visitor Center. 

This includes CA Interstate 10 between mile markers 85 and 100.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building. 

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 3371 11547 3369 11548 3369 11545 3368 11544
      3359 11562 3373 11587 3387 11572 3387 11558
TIME...MOT...LOC 2021Z 137DEG 16KT 3371 11561 

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...50 MPH

$$

INS

The office that day

Everything else NWS Phoenix, AZ issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 9, 1:29 PM PDTSevere Thunderstorm WarningPSRRiverside46 min
Sep 9, 1:58 PM PDTSpecial Weather StatementPSRRiverside32 min
Sep 9, 2:00 PM PDTSevere Thunderstorm WarningPSRRiverside45 min
Sep 9, 2:31 PM PDTSpecial Weather StatementPSRRiverside29 min
Sep 9, 3:42 PM PDTSpecial Weather StatementPSRRiverside33 min
Sep 9, 4:15 PM PDTSpecial Weather StatementPSRRiverside45 min

Nearby

Special Weather Statements in California, 2021Every special weather statement 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.