Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 170, NWS Tucson, AZ

August 30, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 30, 2021, 4:50 PM MST for Pima County, Arizona. It was in force for 40 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: Aug 30, 2021, 4:50 PM MST (23:50 UTC)
Expired: Aug 30, 2021, 5:30 PM MST
In force: 40 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Pima County, AZ

The radar

The Tucson radar (KEMX), 69 km from the middle of the area, began a volume at 23:52 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 12:00Z, 11.8 hours before the alert went out and 40 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: 48 J/kg
Mixed-layer CIN: -250 J/kg
Mixed-layer LCL: 2325 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 10 m²/s²
0-3 km storm-relative helicity: 7 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

607 
WUUS55 KTWC 302350
SVRTWC
AZC019-310030-
/O.NEW.KTWC.SV.W.0170.210830T2350Z-210831T0030Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
450 PM MST Mon Aug 30 2021

The National Weather Service in Tucson has issued a

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

* Until 530 PM MST.

* At 449 PM MST, a severe thunderstorm was located over Three 
  Points, and is nearly stationary.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Three Points.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3205 11122 3200 11139 3214 11153 3224 11124
TIME...MOT...LOC 2349Z 158DEG 3KT 3207 11133 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Carpenter

2 follow-up statements

496 
WWUS55 KTWC 310014
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
514 PM MST Mon Aug 30 2021

AZC019-310030-
/O.CON.KTWC.SV.W.0170.000000T0000Z-210831T0030Z/
Pima-
514 PM MST Mon Aug 30 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 530 PM MST
FOR CENTRAL PIMA COUNTY...

At 513 PM MST, a severe thunderstorm was located near Three Points, 
and is nearly stationary.

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

SOURCE...Radar indicated.

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

Locations impacted include...
Three Points.

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 3210 11125 3200 11139 3214 11153 3224 11124
TIME...MOT...LOC 0013Z 158DEG 3KT 3209 11134 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...0.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Carpenter

977 
WWUS55 KTWC 310028
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
528 PM MST Mon Aug 30 2021

AZC019-310037-
/O.EXP.KTWC.SV.W.0170.000000T0000Z-210831T0030Z/
Pima-
528 PM MST Mon Aug 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL PIMA COUNTY WILL
EXPIRE AT 530 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 3210 11125 3200 11139 3214 11153 3224 11124
TIME...MOT...LOC 0027Z 158DEG 3KT 3210 11134 

$$

Carpenter

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 29, 5:32 PM MST	Special Weather Statement	TWC	Pinal	43 min
Aug 29, 6:49 PM MST	Special Weather Statement	TWC		41 min
Aug 29, 6:53 PM MST	Severe Thunderstorm Warning	TWC	Pima	18 min
Aug 29, 7:46 PM MST	Special Weather Statement	TWC	Graham	44 min
Aug 29, 8:06 PM MST	Areal Flood Advisory	TWC	Graham	3 hr
Aug 30, 2:01 AM MST	Flash Flood Watch	TWC	Cochise, Graham, Greenlee, Pima, Pinal, Santa Cruz	60 hr
Aug 30, 3:38 PM MST	Special Weather Statement	TWC	Pima	52 min
Aug 30, 3:41 PM MST	Special Weather Statement	TWC		49 min
Aug 30, 3:45 PM MST	Special Weather Statement	TWC	Pima	45 min
Aug 30, 4:06 PM MST	Areal Flood Advisory	TWC	Pima	114 min
Aug 30, 4:24 PM MST	Special Weather Statement	TWC		36 min
Aug 30, 4:32 PM MST	Special Weather Statement	TWC		43 min
Aug 30, 4:51 PM MST	Areal Flood Advisory	TWC	Pima	100 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.