Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 34, NWS Phoenix, AZ

July 23, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 23, 2002, 7:49 PM MST for Maricopa County, Arizona. It was in force for 71 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 23, 2002, 7:49 PM MST (02:49 UTC)
Expired: Jul 23, 2002, 9:00 PM MST
In force: 71 min
Issued by: NWS Phoenix, AZ
Area: Counties, with a storm outline in the text

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 56 km from the middle of the area, began a volume at 02:50 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 23, 8:27 PM MST	Thunderstorm Wind 52 E	Scottsdale, AZ	At least 2 trees blown down in north Scottsdale. Heavy rain and lightning were blamed for the collapse of a section of a roof of the Goodwill store in south Scottsdale. One man inside the store suffered minor injuries. Trees and cactus blown down in Glenda

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 2.8 hours before the alert went out and 27 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: -34 J/kg
Mixed-layer LCL: 2526 m above ground
0-6 km bulk shear: 9 kt
0-1 km storm-relative helicity: 15 m²/s²
0-3 km storm-relative helicity: 18 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.

204 
WUUS55 KPSR 240249
SVRPSR
AZC013-240400-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
747 PM MST TUE JUL 23 2002

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA

* UNTIL 900 PM MST

* AT 730 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED
  SEVERE THUNDERSTORMS BUILDING OVER CENTRAL AND NORTH PORTIONS
  OF THE GREATER PHOENIX AREA...EXPANDING WEST.

  THE SEVERE THUNDERSTORM WARNING ISSUED EARLIER FOR EASTERN AND 
  CENTRAL PHOENIX HAS BEEN EXPANDED TO INCLUDE MUCH OF THE
  WEST AND NORTH PORTIONS OF THE GREATER PHOENIX AREA UNTIL 
  9 PM.  THIS INCLUDES THE COMMUNITIES OF CENTRAL AND NORTH
  PHOENIX...PEORIA...GLENDALE...CAVE CREEK...AVONDALE...AND
  PARADISE VALLEY.

THESE ARE DANGEROUS STORMS CAPABLE OF PRODUCING DAMAGING WINDS
IN EXCESS OF 57 MPH...EXTREMELY HEAVY RAIN...LARGE HAIL...
AND DEADLY LIGHTNING.

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

LAT...LON 3385 11239 3332 11239 3323 11173 3393 11167

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Phoenix, AZ wrote its last area forecast discussion before this severe thunderstorm warning went out at Jul 23, 3:15 PM MST, 4 hours 34 minutes earlier.

Area forecast discussion, Jul 23, 3:15 PM MST, 4 hours 34 minutes before

AZZ020>028-CAZ030>033-240545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 PM MST TUE JUL 23 2002

.SYNOPSIS...
HIGH PRESSURE ALOFT WILL CONTINUE OVER SOUTHERN UTAH THROUGH
THURSDAY. THE CLOCKWISE FLOW OF AIR AROUND THE HIGH IS BRINGING AN
INCREASE IN HUMIDITY FROM THE EAST. AS A RESULT...SCATTERED SHOWERS
AND THUNDERSTORMS WILL SPREAD WEST OVER THE AREA THROUGH TONIGHT
WITH A CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS AND
THUNDERSTORMS CONTINUING THROUGH THURSDAY. A PACIFIC LOW PRESSURE
SYSTEM WILL MOVE EAST AND BRING A DRYING TREND TO SOUTHEAST
CALIFORNIA FRIDAY...WITH DRIER AIR SPREADING EAST TO SOUTH-CENTRAL
ARIZONA THIS WEEKEND.

.DISCUSSION...
HIGH PRESSURE ALOFT WILL CONTINUE OVER SOUTHERN UTAH THROUGH
THURSDAY. EXPECT MORE HUMID AIR TO MOVE IN FROM THE EAST AND
SOUTHEAST IN THE CLOCKWISE FLOW AROUND THE HIGH PRESSURE CENTER.
ALSO...THERE MAY BE ADDITIONAL LOW LEVEL MOISTURE FROM THE GULF OF
CALIFORNIA IN THE NEXT DAY OR SO. THE AIRMASS IS UNSTABLE ENOUGH
WITH THE MOISTURE INCREASE TO SUPPORT THUNDERSTORMS DEVELOPING FROM
THE EAST AND SOUTHEAST INTO THE GREATER PHOENIX AREA TONIGHT...AND
EVEN FURTHER WEST AND NORTHWEST. A HAZARDOUS WEATHER OUTLOOK WAS
ISSUED FOR SOUTH-CENTRAL AND SOUTHWEST ARIZONA...INCLUDING THE
GREATER PHOENIX AREA...FOR THIS AFTERNOON AND TONIGHT. AS USUAL IT
IS UNDER THE SPECIAL WEATHER STATEMENT HEADER PHXSPSPSR...WMO HEADER
WWUS85 KPSR. A PACIFIC LOW PRESSURE SYSTEM IS EXPECTED TO MOVE EAST
OVER THE WESTERN UNITED STATES BRINGING DRIER AIR OVER SOUTHEAST
CALIFORNIA FRIDAY...WITH DRIER AIR SPREADING EAST TO SOUTHWEST AND
SOUTH-CENTRAL ARIZONA THIS WEEKEND...AND SOME CORRESPONDING INCREASE
IN DAYTIME HIGH TEMPERATURES.

PSR...NONE

ELLIS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 23, 5:38 PM MST	Severe Thunderstorm Warning	PSR	Pinal	37 min
Jul 23, 6:23 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	52 min
Jul 23, 6:27 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	48 min
Jul 23, 6:30 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	60 min
Jul 23, 6:51 PM MST	Severe Thunderstorm Warning	PSR	Pinal	39 min
Jul 23, 7:06 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	54 min
Jul 23, 8:45 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	45 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2002 Every severe thunderstorm warning in 2002

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.