Alert archive / Arizona / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 21, NWS Tucson, AZ

August 1, 2020Graham County, Greenlee County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 1, 2020, 2:41 PM MST for Graham County, Greenlee 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: Aug 1, 2020, 2:41 PM MST (21:41 UTC)
Expired: Aug 1, 2020, 3:30 PM MST
In force: 49 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Graham County, AZ, Greenlee County, AZ

The radar

The Flagstaff radar (KFSX), 192 km from the middle of the area, began a volume at 21:44 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, 9.7 hours before the alert went out and 209 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: 149 J/kg
Mixed-layer CIN: -403 J/kg
Mixed-layer LCL: 2821 m above ground
0-6 km bulk shear: 26 kt
0-1 km storm-relative helicity: -29 m²/s²
0-3 km storm-relative helicity: 75 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 2.9

Open this sounding in Storm Lab

The text

As transmitted.

815 
WUUS55 KTWC 012141
SVRTWC
AZC009-011-012230-
/O.NEW.KTWC.SV.W.0021.200801T2141Z-200801T2230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Tucson AZ
241 PM MST Sat Aug 1 2020

The National Weather Service in Tucson has issued a

* Severe Thunderstorm Warning for...
  North central Graham County in southeastern Arizona...
  Northwestern Greenlee County in southeastern Arizona...

* Until 330 PM MST.

* At 240 PM MST, a severe thunderstorm was located 10 miles west of
  Hannagan Meadow, moving south at 10 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.

* This severe thunderstorm will remain over mainly remote areas of
  north central Graham and northwestern Greenlee Counties.

This includes Route 191 between mile markers 211 and 229.
 
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 3348 10928 3343 10962 3361 10961 3362 10957
      3362 10953 3364 10952 3366 10948 3370 10947
      3369 10946 3371 10945 3372 10938
TIME...MOT...LOC 2140Z 357DEG 11KT 3366 10950 

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

Carpenter

2 follow-up statements

736 
WWUS55 KTWC 012206
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
306 PM MST Sat Aug 1 2020

AZC009-011-012230-
/O.CON.KTWC.SV.W.0021.000000T0000Z-200801T2230Z/
Graham-Greenlee-
306 PM MST Sat Aug 1 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM MST
FOR NORTH CENTRAL GRAHAM AND NORTHWESTERN GREENLEE COUNTIES...

At 306 PM MST, a severe thunderstorm was located 10 miles southwest
of Hannagan Meadow, moving south 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.

This severe thunderstorm will remain over mainly remote areas of
north central Graham and northwestern Greenlee Counties.

This includes Route 191 between mile markers 211 and 229.
 
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 3348 10928 3343 10962 3361 10961 3362 10957
      3362 10953 3364 10952 3366 10948 3370 10947
      3369 10946 3371 10945 3372 10938
TIME...MOT...LOC 2206Z 357DEG 11KT 3358 10949 

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

Carpenter

620 
WWUS55 KTWC 012223
SVSTWC

Severe Weather Statement
National Weather Service Tucson AZ
323 PM MST Sat Aug 1 2020

AZC009-011-012233-
/O.EXP.KTWC.SV.W.0021.000000T0000Z-200801T2230Z/
Graham-Greenlee-
323 PM MST Sat Aug 1 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL GRAHAM AND
NORTHWESTERN GREENLEE COUNTIES WILL EXPIRE AT 330 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.

LAT...LON 3348 10928 3343 10962 3361 10961 3362 10957
      3362 10953 3364 10952 3366 10948 3370 10947
      3369 10946 3371 10945 3372 10938
TIME...MOT...LOC 2223Z 357DEG 11KT 3354 10949 

$$

Cerniglia

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 5:44 PM MST	Areal Flood Advisory	TWC	Pima, Pinal	107 min
Jul 31, 6:18 PM MST	Areal Flood Advisory	TWC	Pima, Santa Cruz	117 min
Jul 31, 6:27 PM MST	Special Weather Statement	TWC		48 min
Jul 31, 7:14 PM MST	Flash Flood Warning Considerable damage threat	TWC	Pima, Santa Cruz	2 hr
Jul 31, 7:19 PM MST	Special Weather Statement	TWC	Santa Cruz	26 min
Jul 31, 7:28 PM MST	Special Weather Statement	TWC	Greenlee	47 min
Jul 31, 8:15 PM MST	Areal Flood Advisory	TWC	Santa Cruz	2 hr
Jul 31, 8:15 PM MST	Special Weather Statement	TWC	Greenlee	45 min
Jul 31, 10:26 PM MST	Special Weather Statement	TWC		49 min
Aug 1, 2:12 PM MST	Special Weather Statement	TWC	Greenlee	48 min
Aug 1, 2:34 PM MST	Areal Flood Advisory	TWC	Greenlee	3 hr
Aug 1, 3:06 PM MST	Special Weather Statement	TWC	Greenlee	54 min
Aug 1, 3:46 PM MST	Special Weather Statement	TWC		44 min
Aug 1, 4:04 PM MST	Severe Thunderstorm Warning	TWC	Graham	41 min
Aug 1, 4:46 PM MST	Severe Thunderstorm Warning	TWC	Graham, Pinal	44 min
Aug 1, 4:49 PM MST	Special Weather Statement	TWC	Graham	26 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2020 Every severe thunderstorm warning in 2020

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.