Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 168, NWS Tucson, AZ

August 28, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 28, 2021, 8:03 PM MST for Pima County, Arizona. It was in force for 57 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 28, 2021, 8:03 PM MST (03:03 UTC)
Expired
Aug 28, 2021, 9:00 PM MST
In force
57 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), 149 km from the middle of the area, began a volume at 03:06 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 00:00Z, 3.1 hours before the alert went out and 149 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-pSkew-T log-p diagram, Phoenix, AZ at 00:00Z on 2021-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 645 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2021-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -11 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
645 J/kg
Mixed-layer CIN
-152 J/kg
Mixed-layer LCL
3094 m above ground
0-6 km bulk shear
5 kt
0-1 km storm-relative helicity
-11 m²/s²
0-3 km storm-relative helicity
21 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

275 
WUUS55 KTWC 290303
SVRTWC
AZC019-290400-
/O.NEW.KTWC.SV.W.0168.210829T0303Z-210829T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
803 PM MST Sat Aug 28 2021

The National Weather Service in Tucson has issued a

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

* Until 900 PM MST.

* At 803 PM MST, a severe thunderstorm was located 7 miles northwest
  of Gu Vo, or 20 miles southeast of Ajo, and is nearly stationary.

  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...
  Gu Vo, Hickiwan, Organ Pipe Cactus National Monument, Why, Charco
  27, Gunsight and Kuakatch.

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 3203 11255 3212 11286 3243 11269 3239 11231
TIME...MOT...LOC 0303Z 200DEG 2KT 3215 11264 

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

$$

GL
2 follow-up statements
991 
WWUS55 KTWC 290326
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
826 PM MST Sat Aug 28 2021

AZC019-290400-
/O.CON.KTWC.SV.W.0168.000000T0000Z-210829T0400Z/
Pima-
826 PM MST Sat Aug 28 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 900 PM MST
FOR NORTHWESTERN PIMA COUNTY...

At 826 PM MST, a severe thunderstorm was located 10 miles southwest
of Hickiwan, or 17 miles southeast of Ajo, and is nearly stationary.

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...
Gu Vo, Hickiwan, Organ Pipe Cactus National Monument, Why, Charco 27,
Gunsight and Kuakatch.

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 3203 11255 3212 11286 3243 11269 3239 11231
TIME...MOT...LOC 0326Z 073DEG 3KT 3225 11262 

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

$$

GL
352 
WWUS55 KTWC 290353
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
853 PM MST Sat Aug 28 2021

AZC019-290402-
/O.EXP.KTWC.SV.W.0168.000000T0000Z-210829T0400Z/
Pima-
853 PM MST Sat Aug 28 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN PIMA COUNTY WILL
EXPIRE AT 900 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 gusty 
winds and heavy rain are still possible with this thunderstorm and a 
Flash Flood Warning remains in effect. 

LAT...LON 3203 11255 3212 11286 3243 11269 3239 11231
TIME...MOT...LOC 0352Z 200DEG 2KT 3226 11262 

$$

GL

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 28, 5:03 PM MSTFlash Flood Warning Considerable damage threatTWCPima, Pinal117 min
Aug 28, 5:12 PM MSTSpecial Weather StatementTWCPinal48 min
Aug 28, 5:20 PM MSTSevere Thunderstorm WarningTWCPinal40 min
Aug 28, 6:31 PM MSTSevere Thunderstorm WarningTWCPima44 min
Aug 28, 6:47 PM MSTSpecial Weather StatementTWCPinal43 min
Aug 28, 7:01 PM MSTAreal Flood WarningTWCPima, Pinal3 hr
Aug 28, 7:14 PM MSTSevere Thunderstorm WarningTWCPima61 min
Aug 28, 7:41 PM MSTFlash Flood WarningTWCPima109 min
Aug 28, 8:25 PM MSTFlash Flood Warning Considerable damage threatTWCPima2 hr
Aug 29, 2:32 PM MSTSpecial Weather StatementTWCCochise43 min
Aug 29, 3:53 PM MSTSpecial Weather StatementTWCPima37 min
Aug 29, 4:23 PM MSTAreal Flood AdvisoryTWCPima112 min
Aug 29, 4:46 PM MSTSpecial Weather StatementTWCPinal59 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2021Every 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.