Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 97, NWS Tucson, AZ

July 30, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 30, 2021, 5:20 PM MST for Pima County, Arizona. It was in force for 55 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 30, 2021, 5:20 PM MST (00:20 UTC)
Expired: Jul 30, 2021, 6:15 PM MST
In force: 55 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Pima County, AZ

The radar

The Phoenix radar (KIWA), 148 km from the middle of the area, began a volume at 00:20 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, 0.3 hours before the alert went out and 141 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: 50 J/kg
Mixed-layer CIN: -40 J/kg
Mixed-layer LCL: 3059 m above ground
0-6 km bulk shear: 5 kt
0-1 km storm-relative helicity: 1 m²/s²
0-3 km storm-relative helicity: 43 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

030 
WUUS55 KTWC 310020
SVRTWC
AZC019-310115-
/O.NEW.KTWC.SV.W.0097.210731T0020Z-210731T0115Z/

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

The National Weather Service in Tucson has issued a

* Severe Thunderstorm Warning for...
  Northwestern Pima County in southeastern Arizona...

* Until 615 PM MST.

* At 519 PM MST, a severe thunderstorm was located 7 miles southeast
  of Ajo, moving northwest at 10 mph.

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

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  Ajo, Organ Pipe Cactus National Monument, Why and Gunsight. 

This includes the following highways...
 Route 85 between mile markers 33 and 62.
 Route 86 between mile markers 53 and 60.

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 3251 11291 3251 11278 3234 11261 3208 11269
      3236 11306
TIME...MOT...LOC 0019Z 130DEG 10KT 3232 11275 

HAIL...1.00IN
WIND...60MPH
 
$$

Meyer

2 follow-up statements

774 
WWUS55 KTWC 310048
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
548 PM MST Fri Jul 30 2021

AZC019-310115-
/O.CON.KTWC.SV.W.0097.000000T0000Z-210731T0115Z/
Pima-
548 PM MST Fri Jul 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM MST
FOR NORTHWESTERN PIMA COUNTY...

At 544 PM MST, a severe thunderstorm was located near Ajo, moving
northwest 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...
Ajo, Why and Gunsight. 

This includes the following highways...
 Route 85 between mile markers 33 and 62.
 Route 86 between mile markers 53 and 60.

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 3251 11291 3251 11278 3234 11261 3208 11269
      3236 11306
TIME...MOT...LOC 0044Z 130DEG 10KT 3237 11282 

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

Meyer

440 
WWUS55 KTWC 310108
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
608 PM MST Fri Jul 30 2021

AZC019-310118-
/O.EXP.KTWC.SV.W.0097.000000T0000Z-210731T0115Z/
Pima-
608 PM MST Fri Jul 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN PIMA COUNTY WILL
EXPIRE AT 615 PM MST...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However heavy rain is still possible with this
thunderstorm.

LAT...LON 3251 11291 3251 11278 3234 11261 3208 11269
      3236 11306
TIME...MOT...LOC 0108Z 130DEG 10KT 3240 11286 

$$

Meyer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 5:22 PM MST	Severe Thunderstorm Warning	TWC	Pima	29 min
Jul 30, 6:11 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 30, 6:33 PM MST	Special Weather Statement	TWC		42 min
Jul 30, 6:52 PM MST	Special Weather Statement	TWC		38 min
Jul 30, 7:10 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 30, 7:20 PM MST	Areal Flood Advisory	TWC	Pima	4 hr
Jul 30, 7:40 PM MST	Special Weather Statement	TWC		65 min
Jul 30, 7:49 PM MST	Severe Thunderstorm Warning	TWC	Pima	41 min
Jul 30, 7:51 PM MST	Areal Flood Advisory	TWC	Pima	114 min
Jul 30, 7:57 PM MST	Severe Thunderstorm Warning	TWC	Pima	48 min
Jul 30, 7:59 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 30, 8:20 PM MST	Severe Thunderstorm Warning	TWC	Pima	40 min
Jul 30, 8:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 30, 8:35 PM MST	Areal Flood Advisory	TWC	Pima	115 min
Jul 30, 8:47 PM MST	Flash Flood Warning	TWC	Pima	118 min
Jul 30, 9:55 PM MST	Special Weather Statement	TWC	Pinal	65 min
Jul 30, 10:11 PM MST	Flash Flood Warning	TWC	Pima	4 hr
Jul 30, 11:37 PM MST	Flash Flood Warning	TWC	Pima	2 hr
Jul 31, 2:06 AM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 31, 3:51 PM MST	Areal Flood Advisory	TWC	Pinal	114 min
Jul 31, 4:13 PM MST	Special Weather Statement	TWC		47 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.