Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 29, NWS Phoenix, AZ

July 21, 2021Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 21, 2021, 3:53 PM MST for Maricopa County, Arizona. It was in force for 37 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: Jul 21, 2021, 3:53 PM MST (22:53 UTC)
Expired: Jul 21, 2021, 4:30 PM MST
In force: 37 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 70 km from the middle of the area, began a volume at 22:53 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 21, 3:57 PM MST	HAIL 0.25	Avondale, AZ	* DELAYED REPORT * PEA-SIZED HAIL WITH WIND GUSTS ESTIMATED TO 35-40 MPH.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 10.9 hours before the alert went out and 42 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: 5 J/kg
Mixed-layer CIN: -244 J/kg
Mixed-layer LCL: 2438 m above ground
0-6 km bulk shear: 2 kt
0-1 km storm-relative helicity: -11 m²/s²
0-3 km storm-relative helicity: 11 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

298 
WUUS55 KPSR 212253
SVRPSR
AZC013-212330-
/O.NEW.KPSR.SV.W.0029.210721T2253Z-210721T2330Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Phoenix AZ
353 PM MST Wed Jul 21 2021

The National Weather Service in Phoenix has issued a

* Severe Thunderstorm Warning for...
  Maricopa County in south central Arizona...

* Until 430 PM MST.

* At 353 PM MST, a severe thunderstorm was located near Goodyear,
  moving northwest at 5 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Avondale, Goodyear, Buckeye, Litchfield Park, Perryville, Liberty,
  Estrella Mountain Park and Estrella Mountain Ranch.

* This includes the following highways...
  AZ Interstate 10 between mile markers 114 and 128.
  AZ Route 303 between mile markers 105 and 107.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3333 11231 3326 11246 3344 11263 3353 11238
TIME...MOT...LOC 2253Z 149DEG 5KT 3338 11242 

HAIL...<.75IN
WIND...60MPH
 
$$

CK

2 follow-up statements

647 
WWUS55 KPSR 212308
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
408 PM MST Wed Jul 21 2021

AZC013-212330-
/O.CON.KPSR.SV.W.0029.000000T0000Z-210721T2330Z/
Maricopa AZ-
408 PM MST Wed Jul 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 430 PM MST
FOR MARICOPA COUNTY...

At 407 PM MST, a severe thunderstorm was located over Estrella
Mountain Ranch, or near Goodyear, and is nearly stationary.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Avondale, Goodyear, Buckeye, Litchfield Park, Perryville, Liberty,
Estrella Mountain Park and Estrella Mountain Ranch.

This includes the following highways...
AZ Interstate 10 between mile markers 114 and 128.
AZ Route 303 between mile markers 105 and 107.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3333 11231 3326 11246 3344 11263 3353 11238
TIME...MOT...LOC 2307Z 159DEG 2KT 3336 11242 

HAIL...<.75IN
WIND...60MPH
 
$$

CK

183 
WWUS55 KPSR 212326
SVSPSR

Severe Weather Statement
National Weather Service Phoenix AZ
426 PM MST Wed Jul 21 2021

AZC013-212336-
/O.EXP.KPSR.SV.W.0029.000000T0000Z-210721T2330Z/
Maricopa AZ-
426 PM MST Wed Jul 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR MARICOPA COUNTY WILL EXPIRE AT
430 PM MST...
                
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.

LAT...LON 3333 11231 3326 11246 3344 11263 3353 11238
TIME...MOT...LOC 2326Z 149DEG 5KT 3338 11244 

$$

CK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 5:15 PM MST	Special Weather Statement	PSR	La Paz	45 min
Jul 20, 5:21 PM MST	Special Weather Statement	PSR	Gila	39 min
Jul 20, 5:32 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr
Jul 20, 6:22 PM MST	Special Weather Statement	PSR		38 min
Jul 20, 7:22 PM MST	Special Weather Statement	PSR	Pinal	53 min
Jul 20, 8:19 PM MST	Special Weather Statement	PSR	Pinal	41 min
Jul 20, 8:56 PM MST	Special Weather Statement	PSR	Pinal	49 min
Jul 20, 11:51 PM MST	Special Weather Statement	PSR		39 min
Jul 21, 2:21 AM MST	Flash Flood Watch	PSR	Gila, Maricopa, Pinal	5 days
Jul 21, 8:12 AM MST	Blowing Dust Advisory	PSR	La Paz, Maricopa, Yuma	12 hr
Jul 21, 2:45 PM MST	Special Weather Statement	PSR		45 min
Jul 21, 2:46 PM MST	Dust Storm Warning	PSR	Pinal	40 min
Jul 21, 3:07 PM MST	Special Weather Statement	PSR		38 min
Jul 21, 3:34 PM MST	Special Weather Statement	PSR	Maricopa	41 min
Jul 21, 3:37 PM MST	Special Weather Statement	PSR	La Paz	38 min
Jul 21, 3:42 PM MST	Special Weather Statement	PSR	Yuma	48 min
Jul 21, 3:45 PM MST	Special Weather Statement	PSR	Maricopa	45 min
Jul 21, 3:46 PM MST	Special Weather Statement	PSR		29 min
Jul 21, 3:51 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 21, 3:55 PM MST	Special Weather Statement	PSR	Maricopa	50 min
Jul 21, 4:01 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	29 min
Jul 21, 4:11 PM MST	Special Weather Statement	PSR	La Paz	49 min
Jul 21, 4:26 PM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 21, 4:28 PM MST	Special Weather Statement	PSR	Maricopa	47 min
Jul 21, 4:32 PM MST	Special Weather Statement	PSR		28 min
Jul 21, 4:55 PM MST	Flash Flood Warning Considerable damage threat	PSR	La Paz	4 hr
Jul 21, 4:59 PM MST	Special Weather Statement	PSR		46 min

Nearby

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.