Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 79, NWS Tucson, AZ

July 20, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 20, 2021, 8:17 PM MST for Pima County, Arizona. It was in force for 58 min. 3 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 20, 2021, 8:17 PM MST (03:17 UTC)
Expired: Jul 20, 2021, 9:15 PM MST
In force: 58 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 Tucson radar (KEMX), 43 km from the middle of the area, began a volume at 03:17 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 20, 8:21 PM MST	TSTM WND DMG	4 Nne Tucson, AZ	2 LARGE TREES DOWN AT GOLF N STUFF. TIME ESTIMATED FROM RADAR.
Jul 20, 8:22 PM MST	TSTM WND DMG	2 Nne Tucson, AZ	TWITTER PHOTOS INDICATE STORM DAMAGE TO A CHURCH. TIME ESTIMATED FROM RADAR.
Jul 20, 8:29 PM MST	TSTM WND DMG	4 Nne Tucson, AZ	TREE KNOCKED OVER DUE TO STRONG THUNDERSTORM WINDS. TANQUE VERDE AND CAMINO SERNA AREA.

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

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 3.3 hours before the alert went out and 3 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.

825 
WUUS55 KTWC 210317
SVRTWC
AZC019-210415-
/O.NEW.KTWC.SV.W.0079.210721T0317Z-210721T0415Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
817 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...

* Until 915 PM MST.

* At 816 PM MST, a severe thunderstorm was located near southeast 
  Tucson, moving west 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...
  Tucson, Marana, Davis-Monthan Air Force Base, Casas Adobes, Drexel
  Heights, Flowing Wells, Tanque Verde, South Tucson, Pascua Pueblo
  Yaqui Reservation, Tucson International Airport, Valencia West,
  Summit, Catalina Foothills, Tucson Estates, Rita Ranch and San
  Xavier Mission.

This includes the following highways...
 Interstate 10 between mile markers 251 and 272.
 Interstate 19 between mile markers 54 and 63.
 Route 77 between mile markers 70 and 72.
 Route 86 between mile markers 164 and 171.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3226 11077 3207 11082 3204 11112 3233 11109
TIME...MOT...LOC 0316Z 097DEG 11KT 3217 11089 

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

Meyer

2 follow-up statements

881 
WWUS55 KTWC 210337
SVSTWC

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

AZC019-210415-
/O.CON.KTWC.SV.W.0079.000000T0000Z-210721T0415Z/
Pima-
837 PM MST Tue Jul 20 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 915 PM MST
FOR NORTHEASTERN PIMA COUNTY...

At 834 PM MST, a severe thunderstorm was located near north central 
to northeast Tucson, moving west and 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...
Tucson, Davis-Monthan Air Force Base, Casas Adobes, Drexel Heights, 
Flowing Wells, Tanque Verde, Tucson International Airport, Summit, 
Catalina Foothills, and Tucson Estates.

This includes the following highways...
 Interstate 10 between mile markers 251 and 272.
 Interstate 19 between mile markers 54 and 63.
 Route 77 between mile markers 70 and 72.
 Route 86 between mile markers 164 and 171.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3226 11077 3207 11082 3204 11112 3233 11109
TIME...MOT...LOC 0334Z 115DEG 11KT 3224 11092 

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

Meyer

778 
WWUS55 KTWC 210410
SVSTWC

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

AZC019-210419-
/O.EXP.KTWC.SV.W.0079.000000T0000Z-210721T0415Z/
Pima-
910 PM MST Tue Jul 20 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PIMA COUNTY WILL
EXPIRE AT 915 PM MST...
        
The storm which prompted the warning through central to northern 
Tucson has weakened below severe limits, and has moved northwest the 
warned area. Therefore, the warning will be allowed to expire. 
However heavy rain is still possible with this thunderstorm.

LAT...LON 3226 11077 3207 11082 3204 11112 3233 11109
TIME...MOT...LOC 0409Z 097DEG 11KT 3225 11101 

$$

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, 8:40 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, 9:24 PM MST	Severe Thunderstorm Warning	TWC	Pima, Pinal	51 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.