Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 35, NWS Phoenix, AZ

July 23, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 23, 2002, 8:45 PM MST for Maricopa County, Arizona. It was in force for 45 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
Jul 23, 2002, 8:45 PM MST (03:45 UTC)
Expired
Jul 23, 2002, 9:30 PM MST
In force
45 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), 108 km from the middle of the area, began a volume at 03:45 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.

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, 3.8 hours before the alert went out and 76 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, Phoenix, AZ at 00:00Z on 2002-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 211 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Phoenix, AZ at 00:00Z on 2002-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 15 square meters per square second.1939Sfc1 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
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.

511 
WUUS55 KPSR 240345
SVRPSR
AZC013-240430-

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

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 930 PM MST

* AT 829 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED
  SEVERE THUNDERSTORMS BUILDING TOWARD WITTMANN...CIRCLE CITY...
  AND MORRISTOWN FROM THE EAST.  THUNDERSTORMS COULD BUILD TOWARD
  WICKENBURG LATER THIS EVENING.

THESE ARE DANGEROUS THUNDERSTORMS CAPABLE OF PRODUCING DAMAGING
WINDS IN EXCESS OF 57 MPH...LARGE HAIL...VERY HEAVY RAIN...
AND DEADLY LIGHTNING. STAY INSIDE AND AWAY FROM WINDOWS UNTIL THE 
STORM HAS PASSED.

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 3378 11286 3361 11259 3388 11229 3399 11269

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, 5 hours 30 minutes earlier.

Area forecast discussion, Jul 23, 3:15 PM MST, 5 hours 30 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.

IssuedProductOfficeCountiesLasted
Jul 23, 5:38 PM MSTSevere Thunderstorm WarningPSRPinal37 min
Jul 23, 6:23 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal52 min
Jul 23, 6:27 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal48 min
Jul 23, 6:30 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal60 min
Jul 23, 6:51 PM MSTSevere Thunderstorm WarningPSRPinal39 min
Jul 23, 7:06 PM MSTSevere Thunderstorm WarningPSRMaricopa54 min
Jul 23, 7:49 PM MSTSevere Thunderstorm WarningPSRMaricopa71 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2002Every 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.