Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 81, NWS Tucson, AZ

July 20, 2021Pima County, Pinal County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 20, 2021, 9:24 PM MST for Pima County, Pinal County, Arizona. It was in force for 51 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 20, 2021, 9:24 PM MST (04:24 UTC)
Expired: Jul 20, 2021, 10:15 PM MST
In force: 51 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Hail: 0.88 in
Wind: 60.0 mph

Counties Pima County, AZ, Pinal County, AZ

The radar

The Tucson radar (KEMX), 70 km from the middle of the area, began a volume at 04:25 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

Tuscon, AZ (KTUS), launched 00:00Z, 4.4 hours before the alert went out and 31 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: 712 J/kg
Mixed-layer CIN: -15 J/kg
Mixed-layer LCL: 2745 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 9 m²/s²
0-3 km storm-relative helicity: 49 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

099 
WUUS55 KTWC 210424
SVRTWC
AZC019-021-210515-
/O.NEW.KTWC.SV.W.0081.210721T0424Z-210721T0515Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
924 PM MST Tue Jul 20 2021

The National Weather Service in Tucson has issued a

* Severe Thunderstorm Warning for...
  Northeastern Pima County in southeastern Arizona...
  Southeastern Pinal County in southeastern Arizona...

* Until 1015 PM MST.

* At 923 PM MST, an area of severe thunderstorms was located over 
  near Tortolita and Oro Valley, moving west at 10 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Northwest Tucson, Catalina, Oro Valley, Marana, Casas Adobes, 
  Flowing Wells, Tortolita, Saguaro National Park West, Catalina 
  State Park, Picture Rocks and Dove Mountain.

This includes the following highways...
 Interstate 10 between mile markers 236 and 252.
 Route 77 between mile markers 73 and 87.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3250 11090 3231 11090 3226 11124 3256 11122
TIME...MOT...LOC 0423Z 088DEG 7KT 3244 11102 

HAIL...0.88IN
WIND...60MPH
 
$$

Meyer

1 follow-up statement

785 
WWUS55 KTWC 210507
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
1007 PM MST Tue Jul 20 2021

AZC019-021-210515-
/O.EXP.KTWC.SV.W.0081.000000T0000Z-210721T0515Z/
Pima-Pinal-
1007 PM MST Tue Jul 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PIMA AND
SOUTHEASTERN PINAL COUNTIES WILL EXPIRE AT 1015 PM MST...
        
The storm which prompted the warning northwest of Tucson has moved 
northwestward into southern Pinal County. Therefore, the warning 
will be allowed to expire. A warning continues for south central 
Pinal county.

LAT...LON 3250 11090 3231 11090 3226 11124 3256 11122
TIME...MOT...LOC 0505Z 088DEG 7KT 3244 11110 

$$

Meyer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 20, 6:00 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 20, 6:44 PM MST	Special Weather Statement	TWC		46 min
Jul 20, 7:17 PM MST	Special Weather Statement	TWC	Santa Cruz	43 min
Jul 20, 8:02 PM MST	Severe Thunderstorm Warning	TWC	Pinal	58 min
Jul 20, 8:14 PM MST	Special Weather Statement	TWC		61 min
Jul 20, 8:17 PM MST	Severe Thunderstorm Warning	TWC	Pima	58 min
Jul 20, 8:40 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 20, 8:46 PM MST	Severe Thunderstorm Warning	TWC	Pima	30 min
Jul 20, 9:13 PM MST	Special Weather Statement	TWC		62 min
Jul 20, 9:42 PM MST	Areal Flood Advisory	TWC	Pima, Pinal	2 hr
Jul 20, 9:53 PM MST	Severe Thunderstorm Warning	TWC	Pinal	52 min
Jul 21, 1:50 AM MST	Flash Flood Watch	TWC	Cochise, Graham, Greenlee, Pima, Pinal, Santa Cruz	5 days
Jul 21, 8:18 AM MST	Blowing Dust Advisory	TWC	Pima, Pinal	8 hr
Jul 21, 1:00 PM MST	Special Weather Statement	TWC	Pima	45 min
Jul 21, 1:12 PM MST	Severe Thunderstorm Warning	TWC	Pima	48 min
Jul 21, 1:38 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 21, 1:57 PM MST	Special Weather Statement	TWC	Pima	48 min
Jul 21, 2:09 PM MST	Special Weather Statement	TWC	Pima	51 min
Jul 21, 2:16 PM MST	Severe Thunderstorm Warning	TWC	Pima	44 min
Jul 21, 2:21 PM MST	Dust Storm Advisory	TWC	Pima, Pinal	84 min
Jul 21, 2:51 PM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 21, 3:01 PM MST	Dust Storm Warning	TWC	Pinal	32 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.