Alert archive / California / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 40, NWS Phoenix, AZ

July 30, 2021Imperial County, California; Yuma County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 30, 2021, 5:29 PM PDT for Imperial County, California; Yuma County, Arizona. It was in force for 46 min. 2 reports 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: Jul 30, 2021, 5:29 PM PDT (00:29 UTC)
Expired: Jul 30, 2021, 6:15 PM PDT
In force: 46 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties Yuma County, AZ, Imperial County, CA

The radar

The Yuma radar (KYUX), 10 km from the middle of the area, began a volume at 00:28 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
Jul 30, 5:40 PM PDT	TSTM WND DMG	1 W Somerton, AZ	* DELAYED REPORT * REPORTED POWER POLES DOWN AND APS REPORTED POWER OUTAGES. UNKNOWN HOW MANY POLES BUT SEEMED TO BE SCATTERED, NOT IN GROUPS. TIME ESTIMATED FROM RADAR AND APS OUTAGE TRACKER. RADAR ESTIMATED WINDS BETWEEN 45-60 MPH.
Jul 30, 5:40 PM PDT	TSTM WND DMG	Gadsden, AZ	* DELAYED REPORT * POWER POLES REPORTED TO BE DOWN WITH NUMBER UNKNOWN. DOWNED POWER POLES WERE SCATTERED NOT IN GROUPS. LOCATION AND TIME ESTIMATED BASED OFF RADAR AND APS POWER TRACKER. RADAR ESTIMATED WINDS BETWEEN 45-60 MPH.

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 00:00Z, 0.5 hours before the alert went out and 233 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2564 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: -18 m²/s²
0-3 km storm-relative helicity: 33 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

834 
WUUS55 KPSR 310029
SVRPSR
AZC027-CAC025-310115-
/O.NEW.KPSR.SV.W.0040.210731T0029Z-210731T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
529 PM MST Fri Jul 30 2021

The National Weather Service in Phoenix has issued a

* Severe Thunderstorm Warning for...
  West central Yuma County in southwestern Arizona...
  Southeastern Imperial County in southeastern California...

* Until 615 PM MST/615 PM PDT/.

* At 529 PM MST/529 PM PDT/, a severe thunderstorm was located near
  Somerton, moving west at 10 mph.

  HAZARD...60 mph wind gusts and penny size hail.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Yuma, Somerton, Gadsden, San Luis and Winterhaven. 

* This includes the following highways...
  AZ Interstate 8 between mile markers 1 and 3.
  CA Interstate 8 between mile markers 94 and 96.
  AZ Route 195 between mile markers 5 and 21.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3249 11479 3251 11482 3254 11481 3255 11479
      3256 11481 3262 11481 3263 11478 3272 11472
      3276 11463 3244 11444 3242 11456
TIME...MOT...LOC 0029Z 077DEG 8KT 3254 11470 

HAIL...0.75IN
WIND...60MPH
 
$$

Hirsch

1 follow-up statement

722 
WWUS55 KPSR 310100
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
600 PM MST Fri Jul 30 2021

AZC027-CAC025-310115-
/O.CON.KPSR.SV.W.0040.000000T0000Z-210731T0115Z/
Yuma AZ-Imperial CA-
600 PM MST Fri Jul 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM
MST/615 PM PDT/ FOR WEST CENTRAL YUMA AND SOUTHEASTERN IMPERIAL
COUNTIES...

At 600 PM MST/600 PM PDT/, a severe thunderstorm was located over
Gadsden, moving west at 10 mph.

HAZARD...60 mph wind gusts and penny size hail.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Yuma, Somerton, Gadsden, San Luis and Winterhaven. 

This includes the following highways...
AZ Interstate 8 between mile markers 1 and 3.
CA Interstate 8 between mile markers 94 and 96.
AZ Route 195 between mile markers 5 and 21.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3249 11479 3251 11482 3254 11481 3255 11479
      3256 11481 3262 11481 3263 11478 3272 11472
      3276 11463 3244 11444 3242 11456
TIME...MOT...LOC 0100Z 077DEG 8KT 3252 11478 

HAIL...0.75IN
WIND...60MPH
 
$$

Hirsch

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 5:04 PM PDT	Dust Storm Advisory	PSR	Imperial	41 min
Jul 30, 5:18 PM PDT	Special Weather Statement	PSR	Imperial	72 min
Jul 30, 5:20 PM PDT	Special Weather Statement	PSR	Riverside	70 min
Jul 30, 5:24 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Riverside	4 hr
Jul 30, 5:33 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Jul 30, 5:39 PM PDT	Areal Flood Advisory	PSR	Imperial	3 hr
Jul 30, 5:52 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Riverside	4 hr
Jul 30, 5:59 PM PDT	Dust Storm Warning	PSR	Imperial	45 min
Jul 30, 6:06 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial	4 hr
Jul 30, 6:11 PM PDT	Severe Thunderstorm Warning	PSR	Riverside	79 min
Jul 30, 6:31 PM PDT	Special Weather Statement	PSR	Imperial	74 min
Jul 30, 6:49 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Imperial, Riverside	4 hr
Jul 31, 2:32 PM PDT	Special Weather Statement	PSR	Riverside	28 min
Jul 31, 3:47 PM PDT	Special Weather Statement	PSR	Riverside	28 min
Jul 31, 4:48 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Riverside	3 hr
Jul 30, 5:44 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Yuma	4 hr
Jul 30, 6:51 PM PDT	Severe Thunderstorm Warning	PSR	Yuma	38 min
Jul 30, 7:06 PM PDT	Special Weather Statement	PSR	Pinal	24 min
Jul 30, 7:25 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Yuma	3 hr
Jul 30, 7:32 PM PDT	Areal Flood Advisory	PSR	Yuma	3 hr
Jul 30, 7:51 PM PDT	Special Weather Statement	PSR	Yuma	69 min
Jul 30, 8:02 PM PDT	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 30, 8:29 PM PDT	Dust Storm Advisory	PSR	Maricopa, Pinal	72 min
Jul 30, 8:44 PM PDT	Severe Thunderstorm Warning	PSR	La Paz, Maricopa	61 min
Jul 30, 9:17 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Maricopa	2 hr
Jul 30, 9:40 PM PDT	Special Weather Statement	PSR	Maricopa	65 min
Jul 30, 10:24 PM PDT	Dust Storm Advisory	PSR	Maricopa, Pinal	43 min
Jul 30, 10:37 PM PDT	Special Weather Statement	PSR	Maricopa	23 min
Jul 30, 10:45 PM PDT	Special Weather Statement	PSR		45 min
Jul 30, 11:54 PM PDT	Special Weather Statement	PSR	Maricopa	51 min
Jul 31, 12:37 AM PDT	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 31, 1:34 AM PDT	Areal Flood Advisory	PSR	Maricopa	4 hr
Jul 31, 1:58 AM PDT	Areal Flood Advisory	PSR	Maricopa, Pinal	4 hr
Jul 31, 3:39 AM PDT	Areal Flood Advisory	PSR	La Paz	4 hr
Jul 31, 2:23 PM PDT	Special Weather Statement	PSR	La Paz	37 min
Jul 31, 3:03 PM PDT	Special Weather Statement	PSR	Gila	27 min
Jul 31, 3:18 PM PDT	Special Weather Statement	PSR	La Paz	27 min
Jul 31, 3:31 PM PDT	Flash Flood Warning Considerable damage threat	PSR	Gila	4 hr
Jul 31, 3:44 PM PDT	Special Weather Statement	PSR	La Paz	31 min
Jul 31, 3:55 PM PDT	Areal Flood Advisory	PSR	La Paz	3 hr

Nearby

Severe Thunderstorm Warnings in California, 2021 Severe Thunderstorm Warnings in Arizona, 2021 Every 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.