Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 169, NWS Tucson, AZ

August 29, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 29, 2021, 6:53 PM MST for Pima County, Arizona. It was in force for 18 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 29, 2021, 6:53 PM MST (01:53 UTC)
Expired: Aug 29, 2021, 7:11 PM MST
In force: 18 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), 64 km from the middle of the area, began a volume at 01:53 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, 1.9 hours before the alert went out and 24 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: 199 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 3172 m above ground
0-6 km bulk shear: 10 kt
0-1 km storm-relative helicity: 13 m²/s²
0-3 km storm-relative helicity: 46 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

057 
WUUS55 KTWC 300153
SVRTWC
AZC019-300245-
/O.NEW.KTWC.SV.W.0169.210830T0153Z-210830T0245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
653 PM MST Sun Aug 29 2021

The National Weather Service in Tucson has issued a

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

* Until 745 PM MST.

* At 652 PM MST, a severe thunderstorm was located over Casas Adobes,
  or near Oro Valley, moving west at 10 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Trained weather spotters.

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

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

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Damaging winds and frequent cloud to ground lightning is occurring 
with this storm. Move indoors immediately. Lightning is one of 
nature's leading killers. Remember, if you can hear thunder, you are 
close enough to be struck by lightning.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3245 11090 3225 11084 3221 11118 3246 11126
TIME...MOT...LOC 0152Z 084DEG 10KT 3234 11099 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

Cerniglia

1 follow-up statement

839 
WWUS55 KTWC 300211
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
711 PM MST Sun Aug 29 2021

AZC019-300221-
/O.CAN.KTWC.SV.W.0169.000000T0000Z-210830T0245Z/
Pima-
711 PM MST Sun Aug 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PIMA COUNTY IS
CANCELLED...
                
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 has been cancelled.  However gusty winds are
still possible with this thunderstorm.

LAT...LON 3245 11090 3225 11084 3221 11118 3246 11126
TIME...MOT...LOC 0206Z 084DEG 10KT 3233 11105 

$$

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, 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, 4:50 PM MST	Severe Thunderstorm Warning	TWC	Pima	40 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.