Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 31, NWS Phoenix, AZ

July 21, 2021La Paz County, Yuma County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 21, 2021, 6:18 PM MST for La Paz County, Yuma County, Arizona. It was in force for 42 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: Jul 21, 2021, 6:18 PM MST (01:18 UTC)
Expired: Jul 21, 2021, 7:00 PM MST
In force: 42 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

Counties La Paz County, AZ, Yuma County, AZ

The radar

The Yuma radar (KYUX), 86 km from the middle of the area, began a volume at 01:19 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

Phoenix, AZ (KPSR), launched 00:00Z, 1.3 hours before the alert went out and 210 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: 760 J/kg
Mixed-layer CIN: -12 J/kg
Mixed-layer LCL: 3156 m above ground
0-6 km bulk shear: 19 kt
0-1 km storm-relative helicity: -21 m²/s²
0-3 km storm-relative helicity: 10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

347 
WUUS55 KPSR 220118
SVRPSR
AZC012-027-220200-
/O.NEW.KPSR.SV.W.0031.210722T0118Z-210722T0200Z/

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

The National Weather Service in Phoenix has issued a

* Severe Thunderstorm Warning for...
  South central La Paz County in west central Arizona...
  North central Yuma County in southwestern Arizona...

* Until 700 PM MST.

* At 618 PM MST, severe thunderstorms were located along a line
  extending from 13 miles southeast of Yuma Proving Ground to 16
  miles south of Kofa Wildlife Refuge, moving north at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Yuma Proving Ground and Palm Canyon. 

* This includes AZ Route 95 between mile markers 54 and 85.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3307 11449 3349 11414 3338 11377 3287 11418
TIME...MOT...LOC 0118Z 172DEG 10KT 3297 11422 3326 11396 

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

CK

2 follow-up statements

870 
WWUS55 KPSR 220142
SVSPSR

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

AZC012-220151-
/O.CAN.KPSR.SV.W.0031.000000T0000Z-210722T0200Z/
La Paz AZ-
642 PM MST Wed Jul 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR SOUTH CENTRAL LA PAZ COUNTY IS
CANCELLED...

The storms which prompted the warning have weakened. Therefore, the 
warning has been cancelled.

LAT...LON 3287 11418 3303 11442 3304 11427 3333 11428
      3347 11416 3347 11407 3344 11396 3338 11395
      3338 11378
TIME...MOT...LOC 0141Z 172DEG 10KT 3303 11423 3332 11397 

$$

AZC027-220200-
/O.CON.KPSR.SV.W.0031.000000T0000Z-210722T0200Z/
Yuma AZ-
642 PM MST Wed Jul 21 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 700 PM MST
FOR NORTH CENTRAL YUMA COUNTY...

At 641 PM MST, severe thunderstorms were located along a line
extending from 10 miles southeast of Yuma Proving Ground to 12 miles
south of Kofa Wildlife Refuge, moving north at 10 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Palm Canyon.

This includes AZ Route 95 between mile markers 55 and 60, and between
mile markers 71 and 86.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3287 11418 3303 11442 3304 11427 3333 11428
      3347 11416 3347 11407 3344 11396 3338 11395
      3338 11378
TIME...MOT...LOC 0141Z 172DEG 10KT 3303 11423 3332 11397 

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

CK

215 
WWUS55 KPSR 220155
SVSPSR

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

AZC027-220205-
/O.EXP.KPSR.SV.W.0031.000000T0000Z-210722T0200Z/
Yuma AZ-
655 PM MST Wed Jul 21 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL YUMA COUNTY WILL
EXPIRE AT 700 PM MST...
            
The storms which prompted the warning have weakened below severe
limits, and no longer pose 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 these thunderstorms.

LAT...LON 3287 11418 3303 11442 3304 11427 3333 11428
      3347 11416 3347 11407 3344 11396 3338 11395
      3338 11378
TIME...MOT...LOC 0155Z 172DEG 10KT 3305 11423 3334 11397 

$$

CK

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 21, 5:37 PM MST	Special Weather Statement	PSR	Yuma	38 min
Jul 21, 5:41 PM MST	Special Weather Statement	PSR		49 min
Jul 21, 6:20 PM MST	Special Weather Statement	PSR	Gila	40 min
Jul 21, 6:47 PM MST	Special Weather Statement	PSR		43 min
Jul 21, 6:59 PM MST	Special Weather Statement	PSR	Yuma	46 min
Jul 21, 7:06 PM MST	Areal Flood Advisory	PSR	Gila	3 hr
Jul 21, 7:10 PM MST	Special Weather Statement	PSR	La Paz	50 min
Jul 21, 7:17 PM MST	Areal Flood Advisory	PSR	Yuma	44 min
Jul 21, 7:40 PM MST	Dust Storm Warning	PSR	Yuma	35 min
Jul 21, 8:01 PM MST	Flash Flood Warning Considerable damage threat	PSR	Yuma	4 hr
Jul 21, 8:13 PM MST	Dust Storm Advisory	PSR	Yuma	47 min
Jul 21, 9:06 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	39 min
Jul 21, 10:06 PM MST	Dust Storm Advisory	PSR	Maricopa, Pinal	39 min
Jul 21, 10:11 PM MST	Special Weather Statement	PSR	Pinal	49 min
Jul 21, 10:23 PM MST	Special Weather Statement	PSR	Maricopa	37 min
Jul 21, 10:25 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	16 min
Jul 21, 10:39 PM MST	Special Weather Statement	PSR		36 min
Jul 21, 10:51 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	24 min
Jul 21, 11:12 PM MST	Special Weather Statement	PSR		48 min
Jul 21, 11:15 PM MST	Special Weather Statement	PSR	Pinal	45 min
Jul 22, 12:28 AM MST	Flash Flood Warning Considerable damage threat	PSR	Maricopa	4 hr
Jul 22, 12:32 AM MST	Areal Flood Advisory	PSR	Maricopa	118 min
Jul 22, 3:06 PM MST	Special Weather Statement	PSR		54 min
Jul 22, 3:43 PM MST	Special Weather Statement	PSR	Maricopa	47 min
Jul 22, 3:58 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	33 min
Jul 22, 4:30 PM MST	Dust Storm Advisory	PSR	Yuma	41 min
Jul 22, 4:53 PM MST	Areal Flood Advisory	PSR	Maricopa	3 hr

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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.