Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 151, NWS Tucson, AZ

August 17, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 17, 2021, 7:18 PM MST for Pima County, Arizona. It was in force for 42 min. 6 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: Aug 17, 2021, 7:18 PM MST (02:18 UTC)
Expired: Aug 17, 2021, 8:00 PM MST
In force: 42 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), 35 km from the middle of the area, began a volume at 02:20 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.

What was reported inside it

Time	Report	Where	Remark
Aug 17, 7:21 PM MST	TSTM WND DMG	4 Se Tucson, AZ	TREE IN ROADWAY.
Aug 17, 7:24 PM MST	TSTM WND DMG	4 Se Tucson, AZ	TRAFFIC LIGHT MALFUNCTIONING AT IRVINGTON AND COUNTRY CLUB.
Aug 17, 7:26 PM MST	TSTM WND DMG	3 Sw Tucson, AZ	WIRE DOWN AT IRVINGTON AND TUCSON BLVD.
Aug 17, 7:32 PM MST	TSTM WND DMG	3 Sw Tucson, AZ	POLE LEANING ON IRVINGTON EAST OF CAMPBELL.
Aug 17, 7:32 PM MST	TSTM WND DMG	4 Sw Tucson, AZ	CACTUS HAS FALLEN INTO THE ROADWAY AT TUCSON BLVD AND DREXEL.
Aug 17, 7:33 PM MST	TSTM WND DMG	3 Ssw Tucson, AZ	POWER POLES DOWN AT BENSON HWY AND PALO VERDE.

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, 2.3 hours before the alert went out and 6 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: 1326 J/kg
Mixed-layer CIN: -11 J/kg
Mixed-layer LCL: 1309 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 22 m²/s²
0-3 km storm-relative helicity: -13 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

034 
WUUS55 KTWC 180218
SVRTWC
AZC019-180300-
/O.NEW.KTWC.SV.W.0151.210818T0218Z-210818T0300Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
718 PM MST Tue Aug 17 2021

The National Weather Service in Tucson has issued a

* Severe Thunderstorm Warning for...
  East central Pima County in southeastern Arizona...

* Until 800 PM MST.

* At 718 PM MST, a severe thunderstorm was located over Davis-Monthan
  Air Force Base, moving northeast at 15 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, Tanque Verde, South Tucson,
  Tucson International Airport, Saguaro National Park East, Sabino
  Canyon Recreation Area, Catalina Foothills and Rita Ranch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3206 11088 3216 11101 3233 11079 3220 11061
TIME...MOT...LOC 0218Z 229DEG 14KT 3215 11089 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AH

2 follow-up statements

506 
WWUS55 KTWC 180233
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
733 PM MST Tue Aug 17 2021

AZC019-180300-
/O.CON.KTWC.SV.W.0151.000000T0000Z-210818T0300Z/
Pima-
733 PM MST Tue Aug 17 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 800 PM MST
FOR EAST CENTRAL PIMA COUNTY...

At 732 PM MST, a severe thunderstorm was located over Davis-Monthan 
Air Force Base, moving northeast at 10 mph. There have been multiple 
reports of wind damage.

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

SOURCE...Trained weather spotters.

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

Locations impacted include...
Tucson, Davis-Monthan Air Force Base, Tanque Verde, South Tucson,
Tucson International Airport, Saguaro National Park East, Sabino
Canyon Recreation Area, Catalina Foothills and Rita Ranch.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3206 11088 3216 11101 3233 11079 3220 11061
TIME...MOT...LOC 0232Z 241DEG 9KT 3218 11087 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...1.00 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

AH

402 
WWUS55 KTWC 180254
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
754 PM MST Tue Aug 17 2021

AZC019-180304-
/O.EXP.KTWC.SV.W.0151.000000T0000Z-210818T0300Z/
Pima-
754 PM MST Tue Aug 17 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL PIMA COUNTY WILL
EXPIRE AT 800 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.  However heavy rain
is still possible with this thunderstorm.

LAT...LON 3206 11088 3216 11101 3233 11079 3220 11061
TIME...MOT...LOC 0254Z 229DEG 14KT 3223 11080 

$$

AH

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 7:33 PM MST	Areal Flood Advisory	TWC	Pima	4 min
Aug 17, 7:37 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	113 min
Aug 17, 7:44 PM MST	Areal Flood Advisory	TWC	Graham, Pima, Pinal	3 hr
Aug 17, 9:37 PM MST	Flash Flood Watch	TWC	Cochise, Graham, Greenlee, Pinal	22 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.