Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 94, NWS Tucson, AZ

July 29, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 29, 2021, 1:20 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: Jul 29, 2021, 1:20 PM MST (20:20 UTC)
Expired: Jul 29, 2021, 2:00 PM MST
In force: 40 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 Phoenix radar (KIWA), 159 km from the middle of the area, began a volume at 20:22 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

Phoenix, AZ (KPSR), launched 12:00Z, 8.3 hours before the alert went out and 152 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: 371 J/kg
Mixed-layer CIN: -231 J/kg
Mixed-layer LCL: 2650 m above ground
0-6 km bulk shear: 4 kt
0-1 km storm-relative helicity: 11 m²/s²
0-3 km storm-relative helicity: 5 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

206 
WUUS55 KTWC 292020
SVRTWC
AZC019-292100-
/O.NEW.KTWC.SV.W.0094.210729T2020Z-210729T2100Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
120 PM MST Thu Jul 29 2021

The National Weather Service in Tucson has issued a

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

* Until 200 PM MST.

* At 119 PM MST, a severe thunderstorm was located near Ajo, moving
  west 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...
  Ajo and Organ Pipe Cactus National Monument. 

This includes Route 85 between mile markers 38 and 47.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3242 11275 3212 11287 3215 11315 3247 11307
TIME...MOT...LOC 2019Z 090DEG 11KT 3232 11284 

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

AH

2 follow-up statements

591 
WWUS55 KTWC 292037
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
137 PM MST Thu Jul 29 2021

AZC019-292100-
/O.CON.KTWC.SV.W.0094.000000T0000Z-210729T2100Z/
Pima-
137 PM MST Thu Jul 29 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM MST
FOR NORTHWESTERN PIMA COUNTY...

At 137 PM MST, a severe thunderstorm was located near Ajo, moving
west at 15 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Ajo and Organ Pipe Cactus National Monument. 

This includes Route 85 between mile markers 37 and 45.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3243 11279 3212 11287 3215 11315 3247 11307
TIME...MOT...LOC 2037Z 090DEG 11KT 3232 11291 

HAIL...<.75IN
WIND...60MPH
 
$$

AH

947 
WWUS55 KTWC 292050
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
150 PM MST Thu Jul 29 2021

AZC019-292100-
/O.EXP.KTWC.SV.W.0094.000000T0000Z-210729T2100Z/
Pima-
150 PM MST Thu Jul 29 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN PIMA COUNTY WILL
EXPIRE AT 200 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.

LAT...LON 3243 11279 3212 11287 3215 11315 3247 11307
TIME...MOT...LOC 2050Z 090DEG 11KT 3232 11295 

$$

AH

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 28, 8:12 PM MST	Areal Flood Advisory	TWC	Cochise	63 min
Jul 29, 1:55 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 29, 2:06 PM MST	Flash Flood Watch	TWC	Pima, Pinal	39 hr
Jul 29, 2:08 PM MST	Special Weather Statement	TWC		37 min
Jul 29, 2:42 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	2 hr
Jul 29, 2:44 PM MST	Special Weather Statement	TWC	Cochise	61 min
Jul 29, 3:03 PM MST	Areal Flood Advisory	TWC	Cochise	117 min
Jul 29, 3:10 PM MST	Special Weather Statement	TWC	Graham	35 min
Jul 29, 4:54 PM MST	Areal Flood Advisory	TWC	Graham	2 hr
Jul 29, 4:54 PM MST	Special Weather Statement	TWC		36 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.