Alert archive / Arizona / Severe Thunderstorm Warnings in 2011

Severe Thunderstorm Warning 21, NWS Phoenix, AZ

July 31, 2011Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 31, 2011, 5:46 PM MST for Pinal County, Arizona. It was in force for 29 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 31, 2011, 5:46 PM MST (00:46 UTC)
Expired: Jul 31, 2011, 6:15 PM MST
In force: 29 min
Issued by: NWS Phoenix, AZ
Area: Storm-based polygon

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 53 km from the middle of the area, began a volume at 00:48 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 31, 6:24 PM MST	TSTM WND GST 65	2 Ese Casa Grande, AZ	65 MPH WINDS DAMAGED ROOF OF NEIGHBORING HOUSE

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 0.8 hours before the alert went out and 66 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: 374 J/kg
Mixed-layer CIN: -89 J/kg
Mixed-layer LCL: 2662 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: -1 m²/s²
0-3 km storm-relative helicity: 45 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.

698 
WUUS55 KPSR 010046
SVRPSR
AZC021-010115-
/O.NEW.KPSR.SV.W.0021.110801T0046Z-110801T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
546 PM MST SUN JUL 31 2011

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WEST CENTRAL PINAL COUNTY IN SOUTH CENTRAL ARIZONA... 
  THIS INCLUDES THE CITY OF CASA GRANDE... 

* UNTIL 615 PM MST

* AT 536 PM MST...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS
  OF 60 MPH.  THIS STORM WAS LOCATED 11 MILES WEST OF CASA GRANDE...
  AND MOVING NORTH AT 8 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
  OLBERG

PRECAUTIONARY/PREPAREDNESS ACTIONS...

IF YOU ARE IN A MOBILE HOME...EVACUATE IMMEDIATELY AND GET INSIDE A
STURDY BUILDING. IF YOU CANNOT QUICKLY WALK OR DRIVE TO SHELTER...LIE
FLAT IN THE NEAREST DITCH OR OTHER LOW SPOT AND COVER YOUR HEAD WITH
YOUR HANDS.

IF YOU ENCOUNTER DENSE BLOWING DUST WHILE DRIVING...PULL OVER AS FAR
OFF THE ROADWAY AS POSSIBLE AND PARK. TURN OFF YOUR HEADLIGHTS AND
KEEP YOUR FOOT OFF THE BRAKE.

&&

LAT...LON 3277 11209 3315 11194 3302 11165 3279 11175
      3277 11177 3277 11178 3279 11177 3280 11188
      3277 11189
TIME...MOT...LOC 0045Z 198DEG 7KT 3288 11192

$$

HV

1 follow-up statement

158 
WWUS55 KPSR 010119
SVSPSR

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE PHOENIX AZ
619 PM MST SUN JUL 31 2011

AZC021-010126-
/O.EXP.KPSR.SV.W.0021.000000T0000Z-110801T0115Z/
PINAL AZ-
619 PM MST SUN JUL 31 2011

...THE SEVERE THUNDERSTORM WARNING FOR WEST CENTRAL PINAL COUNTY 
NEAR THE CASA GRANDE AREA EXPIRED

THE SEVERE THUNDERSTORM WARNING FOR CASA GRANDE AND VICINITY WAS 
ALLOWED TO EXPIRE AT 615 PM. POWERFUL THUNDERSTORMS DEVELOPED 11 
MILES WEST OF CASA GRANDE JUST AFTER 545 PM. THERE WERE REPORTS OF A 
COUPLE OF MOBILE HOMES DAMAGED IN THE FRANCISCO GRANDE AREA.

A CHANCE OF STRONG THUNDERSTORMS WILL CONTINUE THE REMAINDER OF THE 
AFTERNOON AND EARLY EVENING.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE.

LAT...LON 3277 11209 3315 11194 3302 11165 3279 11175
      3277 11177 3277 11178 3279 11177 3280 11188
      3277 11189
TIME...MOT...LOC 0046Z 198DEG 7KT 3288 11192

$$

HV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 31, 5:31 PM MST	Dust Storm Warning	PSR		3 hr
Jul 31, 5:35 PM MST	Special Weather Statement	PSR	Pinal	25 min
Jul 31, 6:18 PM MST	Areal Flood Advisory	PSR	Gila	3 hr
Jul 31, 7:01 PM MST	Areal Flood Advisory	PSR	Pinal	119 min
Jul 31, 7:09 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	51 min
Jul 31, 7:17 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	43 min
Jul 31, 7:22 PM MST	Areal Flood Advisory	PSR	Maricopa, Pinal	113 min
Jul 31, 8:41 PM MST	Special Weather Statement	PSR	Maricopa	64 min
Jul 31, 9:07 PM MST	Special Weather Statement	PSR	Maricopa	53 min
Jul 31, 9:17 PM MST	Areal Flood Advisory	PSR	Maricopa	118 min
Aug 1, 3:16 PM MST	Special Weather Statement	PSR		44 min
Aug 1, 4:50 PM MST	Special Weather Statement	PSR		40 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2011 Every severe thunderstorm warning in 2011

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.