Alert archive / Arizona / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 197, NWS Tucson, AZ

September 26, 2021Pima County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Sep 26, 2021, 2:56 PM MST for Pima County, Arizona. It was in force for 49 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
Sep 26, 2021, 2:56 PM MST (21:56 UTC)
Expired
Sep 26, 2021, 3:45 PM MST
In force
49 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 Tucson radar (KEMX), 54 km from the middle of the area, began a volume at 21:56 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, 9.9 hours before the alert went out and 50 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, Tuscon, AZ at 12:00Z on 2021-09-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 252 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, Tuscon, AZ at 12:00Z on 2021-09-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -13 square meters per square second.193958Sfc1 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
252 J/kg
Mixed-layer CIN
-123 J/kg
Mixed-layer LCL
1157 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-13 m²/s²
0-3 km storm-relative helicity
44 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

916 
WUUS55 KTWC 262156
SVRTWC
AZC019-262245-
/O.NEW.KTWC.SV.W.0197.210926T2156Z-210926T2245Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
256 PM MST Sun Sep 26 2021

The National Weather Service in Tucson has issued a

* Severe Thunderstorm Warning for...
  East central Pima County in southeastern Arizona...

* Until 345 PM MST.

* At 256 PM MST, a severe thunderstorm was located 13 miles north of
  Arivaca, or 16 miles west of Green Valley, moving northeast at 20
  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...
  Sahuarita, Green Valley and Arivaca Junction. 

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 3175 11140 3193 11140 3198 11109 3187 11082
      3173 11103 3173 11116 3170 11117 3170 11125
TIME...MOT...LOC 2156Z 228DEG 16KT 3177 11128 

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

$$

KRG
1 follow-up statement
654 
WWUS55 KTWC 262239
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
339 PM MST Sun Sep 26 2021

AZC019-262249-
/O.EXP.KTWC.SV.W.0197.000000T0000Z-210926T2245Z/
Pima-
339 PM MST Sun Sep 26 2021

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL PIMA COUNTY WILL
EXPIRE AT 345 PM MST...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning will be allowed to expire.  However small hail
and gusty winds are still possible with this thunderstorm.

LAT...LON 3175 11140 3193 11140 3198 11109 3187 11082
      3173 11103 3173 11116 3170 11117 3170 11125
TIME...MOT...LOC 2239Z 228DEG 16KT 3190 11112 

$$

KRG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 25, 5:03 PM MSTAreal Flood AdvisoryTWCCochise3 hr
Sep 25, 6:27 PM MSTAreal Flood AdvisoryTWCCochise, Graham, Pima, Pinal3 hr
Sep 25, 6:46 PM MSTFlash Flood Warning Considerable damage threatTWCPima, Pinal3 hr
Sep 25, 7:17 PM MSTAreal Flood AdvisoryTWCPima3 hr
Sep 26, 11:51 AM MSTSpecial Weather StatementTWCCochise39 min
Sep 26, 11:57 AM MSTSevere Thunderstorm WarningTWCCochise28 min
Sep 26, 12:20 PM MSTSpecial Weather StatementTWC40 min
Sep 26, 12:44 PM MSTSpecial Weather StatementTWCSanta Cruz46 min
Sep 26, 12:58 PM MSTSpecial Weather StatementTWCCochise47 min
Sep 26, 1:21 PM MSTSpecial Weather StatementTWC39 min
Sep 26, 1:40 PM MSTSevere Thunderstorm WarningTWCPima, Santa Cruz50 min
Sep 26, 2:18 PM MSTSpecial Weather StatementTWCSanta Cruz42 min
Sep 26, 2:33 PM MSTAreal Flood AdvisoryTWCPima, Santa Cruz104 min
Sep 26, 3:43 PM MSTSpecial Weather StatementTWCSanta Cruz47 min
Sep 26, 4:24 PM MSTSpecial Weather StatementTWCPima51 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.