Alert archive / Arizona / Severe Thunderstorm Warnings in 2012

Severe Thunderstorm Warning 87, NWS Tucson, AZ

August 21, 2012Graham County, Arizona

NWS Tucson, AZ issued this severe thunderstorm warning at Aug 21, 2012, 12:17 PM MST for Graham County, Arizona. It was in force for 28 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 21, 2012, 12:17 PM MST (19:17 UTC)
Expired: Aug 21, 2012, 12:45 PM MST
In force: 28 min
Issued by: NWS Tucson, AZ
Area: Storm-based polygon

County Graham County, AZ

The radar

The Tucson radar (KEMX), 126 km from the middle of the area, began a volume at 19:16 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 (KDMA), launched 12:00Z, 7.3 hours before the alert went out and 114 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: 1386 J/kg
Mixed-layer CIN: -110 J/kg
Mixed-layer LCL: 1261 m above ground
0-6 km bulk shear: 3 kt
0-1 km storm-relative helicity: 17 m²/s²
0-3 km storm-relative helicity: 32 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

977 
WUUS55 KTWC 211917
SVRTWC
AZC009-211945-
/O.NEW.KTWC.SV.W.0087.120821T1917Z-120821T1945Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TUCSON AZ
1217 PM MST TUE AUG 21 2012

THE NATIONAL WEATHER SERVICE IN TUCSON HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL GRAHAM COUNTY IN SOUTHEAST ARIZONA...

* UNTIL 1245 PM MST

* AT 1216 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED 12 MILES SOUTHWEST OF FORT
  THOMAS...OR 23 MILES WEST OF SAFFORD...AND MOVING SOUTHEAST AT 15
  MPH.

* THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL
  AREAS OF THE INDICATED COUNTY.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

SEEK SHELTER INDOORS. EXPECT DAMAGING WINDS IN EXCESS OF 60 MPH...
LARGE HAIL...FREQUENT LIGHTNING...AND HEAVY RAIN WITH THIS STORM.

&&

LAT...LON 3308 11022 3301 10978 3268 10994 3279 11028
TIME...MOT...LOC 1916Z 295DEG 12KT 3285 11008

$$

2 follow-up statements

039 
WWUS55 KTWC 211930
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1230 PM MST TUE AUG 21 2012

AZC009-211945-
/O.CON.KTWC.SV.W.0087.000000T0000Z-120821T1945Z/
GRAHAM AZ-
1230 PM MST TUE AUG 21 2012

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1245 PM MST
FOR CENTRAL GRAHAM COUNTY...

AT 1226 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR CONTINUED TO 
INDICATE A SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING 
THUNDERSTORM OUTFLOW WINDS IN EXCESS OF 60 MPH. 

THIS STORM WAS LOCATED 12 MILES SOUTH OF FORT THOMAS...OR 21 MILES 
WEST OF SAFFORD...MOVING SOUTHEAST AT 15 MPH. THE OUTFLOW IS MOVING 
TO THE EAST...IMPACTING HIGHWAY 70 BETWEEN PIMA AND FORT THOMAS. 



LAT...LON 3308 11022 3301 10978 3268 10994 3279 11028
TIME...MOT...LOC 1926Z 295DEG 12KT 3284 11004

$$

367 
WWUS55 KTWC 211943
SVSTWC

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE TUCSON AZ
1243 PM MST TUE AUG 21 2012

AZC009-211951-
/O.EXP.KTWC.SV.W.0087.000000T0000Z-120821T1945Z/
GRAHAM AZ-
1243 PM MST TUE AUG 21 2012

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL GRAHAM COUNTY WILL
EXPIRE AT 1245 PM MST...

THE STORM THAT PROMPTED THE SEVERE THUNDERSTORM WARNING HAS WEAKENED 
CONSIDERABLY AND IS NO LONGER SEVERE. THEREFORE...THE SEVERE 
THUNDERSTORM HAS BEEN ALLOWED TO EXPIRE AT 1245 PM MST.
 
HOWEVER...STRONG WIND GUSTS TO 45 MPH MAY STILL BE PRESENT ALONG 
HIGHWAY 70 BETWEEN PIMA AND SAFFORD.

LAT...LON 3308 11022 3301 10978 3268 10994 3279 11028
TIME...MOT...LOC 1941Z 295DEG 12KT 3282 10999

$$

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 20, 5:59 PM MST	Flash Flood Warning	TWC	Pima	2 hr
Aug 20, 6:10 PM MST	Areal Flood Advisory	TWC	Pima	80 min
Aug 20, 7:26 PM MST	Areal Flood Advisory	TWC	Pima	109 min
Aug 20, 7:40 PM MST	Special Weather Statement	TWC	Pima	50 min
Aug 21, 1:04 PM MST	Severe Thunderstorm Warning	TWC	Pinal	26 min
Aug 21, 2:10 PM MST	Special Weather Statement	TWC	Cochise	50 min
Aug 21, 2:49 PM MST	Flash Flood Warning	TWC	Pima	86 min
Aug 21, 3:12 PM MST	Special Weather Statement	TWC		48 min
Aug 21, 3:28 PM MST	Severe Thunderstorm Warning	TWC	Cochise, Pima	47 min
Aug 21, 3:34 PM MST	Severe Thunderstorm Warning	TWC	Pima	41 min
Aug 21, 3:53 PM MST	Areal Flood Advisory	TWC	Pima	112 min
Aug 21, 4:15 PM MST	Severe Thunderstorm Warning	TWC	Pima	45 min
Aug 21, 4:34 PM MST	Areal Flood Advisory	TWC	Pima	116 min
Aug 21, 4:42 PM MST	Areal Flood Advisory	TWC	Pima, Santa Cruz	2 hr

Nearby

Severe Thunderstorm Warnings in Arizona, 2012 Every severe thunderstorm warning in 2012

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.