Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 101, NWS Tucson, AZ

July 30, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Jul 30, 2021, 8:20 PM MST for Pima County, Arizona. It was in force for 40 min. 1 report 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: Jul 30, 2021, 8:20 PM MST (03:20 UTC)
Expired: Jul 30, 2021, 9:00 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), 49 km from the middle of the area, began a volume at 03:24 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
Jul 30, 8:30 PM MST	TSTM WND GST 55	2 Se Tucson, AZ	ASOS STATION KDMA DAVIS MONTHAN AFB.

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, 3.3 hours before the alert went out and 9 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: 211 J/kg
Mixed-layer CIN: -25 J/kg
Mixed-layer LCL: 2641 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: 26 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

157 
WUUS55 KTWC 310320
SVRTWC
AZC019-310400-
/O.NEW.KTWC.SV.W.0101.210731T0320Z-210731T0400Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
820 PM MST Fri Jul 30 2021

The National Weather Service in Tucson has issued a

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

* Until 900 PM MST.

* At 819 PM MST, a severe thunderstorm was located over South Tucson,
  or near Tucson, moving northwest at 15 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Tucson, Davis-Monthan Air Force Base, Casas Adobes, Drexel 
  Heights, Flowing Wells, South Tucson, Tortolita, Tucson Estates, 
  Saguaro National Park West, Tucson International Airport, 
  and Valencia West.

This includes the following highways...
 Interstate 10 between mile markers 246 and 267.
 Interstate 19 between mile markers 58 and 63.
 Route 77 between mile markers 70 and 73.
 Route 86 between mile markers 163 and 171.

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 3220 11082 3209 11093 3219 11126 3240 11109
TIME...MOT...LOC 0319Z 122DEG 13KT 3219 11095 

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

Meyer

2 follow-up statements

241 
WWUS55 KTWC 310342
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
842 PM MST Fri Jul 30 2021

AZC019-310400-
/O.CON.KTWC.SV.W.0101.000000T0000Z-210731T0400Z/
Pima-
842 PM MST Fri Jul 30 2021

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

At 840 PM MST, a severe thunderstorm was located over central 
and southern Tucson, moving northwest at 15 mph. A wind gust to 55 
mph was measured at Davis Monthan AFB.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Tucson, Marana, Davis-Monthan Air Force Base, Casas Adobes, Drexel
Heights, Flowing Wells, South Tucson, Tortolita, Tucson Estates,
Saguaro National Park West, Tucson International Airport, and 
Valencia
West.

This includes the following highways...
 Interstate 10 between mile markers 246 and 267.
 Interstate 19 between mile markers 58 and 63.
 Route 77 between mile markers 70 and 73.
 Route 86 between mile markers 163 and 171.

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 3220 11082 3209 11093 3219 11126 3240 11109
TIME...MOT...LOC 0340Z 122DEG 12KT 3222 11100 

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

Meyer

312 
WWUS55 KTWC 310401
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
901 PM MST Fri Jul 30 2021

AZC019-310410-
/O.EXP.KTWC.SV.W.0101.000000T0000Z-210731T0400Z/
Pima-
901 PM MST Fri Jul 30 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN PIMA COUNTY HAS
EXPIRED...
                
The storm which prompted the warning over Tucson has weakened below 
severe limits. Therefore, the warning has been allowed to expire. 
However, heavy rain is still possible with this thunderstorm.

LAT...LON 3220 11082 3209 11093 3219 11126 3240 11109
TIME...MOT...LOC 0400Z 122DEG 13KT 3225 11105 

$$

Meyer

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 30, 5:20 PM MST	Severe Thunderstorm Warning	TWC	Pima	55 min
Jul 30, 5:22 PM MST	Severe Thunderstorm Warning	TWC	Pima	29 min
Jul 30, 6:11 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 30, 6:33 PM MST	Special Weather Statement	TWC		42 min
Jul 30, 6:52 PM MST	Special Weather Statement	TWC		38 min
Jul 30, 7:10 PM MST	Areal Flood Advisory	TWC	Pima	2 hr
Jul 30, 7:20 PM MST	Areal Flood Advisory	TWC	Pima	4 hr
Jul 30, 7:40 PM MST	Special Weather Statement	TWC		65 min
Jul 30, 7:49 PM MST	Severe Thunderstorm Warning	TWC	Pima	41 min
Jul 30, 7:51 PM MST	Areal Flood Advisory	TWC	Pima	114 min
Jul 30, 7:57 PM MST	Severe Thunderstorm Warning	TWC	Pima	48 min
Jul 30, 7:59 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 30, 8:29 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima	3 hr
Jul 30, 8:35 PM MST	Areal Flood Advisory	TWC	Pima	115 min
Jul 30, 8:47 PM MST	Flash Flood Warning	TWC	Pima	118 min
Jul 30, 9:55 PM MST	Special Weather Statement	TWC	Pinal	65 min
Jul 30, 10:11 PM MST	Flash Flood Warning	TWC	Pima	4 hr
Jul 30, 11:37 PM MST	Flash Flood Warning	TWC	Pima	2 hr
Jul 31, 2:06 AM MST	Areal Flood Advisory	TWC	Pima	3 hr
Jul 31, 3:51 PM MST	Areal Flood Advisory	TWC	Pinal	114 min
Jul 31, 4:13 PM MST	Special Weather Statement	TWC		47 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.