Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 43, NWS Phoenix, AZ

September 6, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 6, 2002, 3:22 PM MST for Maricopa County, Arizona. It was in force for 53 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
Sep 6, 2002, 3:22 PM MST (22:22 UTC)
Expired
Sep 6, 2002, 4:15 PM MST
In force
53 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), 34 km from the middle of the area, began a volume at 22:21 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 12:00Z, 10.4 hours before the alert went out and 3 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 12:00Z on 2002-09-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 907 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 12:00Z on 2002-09-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -26 square meters per square second.193958Sfc1 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
907 J/kg
Mixed-layer CIN
-114 J/kg
Mixed-layer LCL
2318 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-26 m²/s²
0-3 km storm-relative helicity
40 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

304 
WUUS55 KPSR 062222
SVRPSR
AZC013-062315-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
319 PM MST FRI SEP 6 2002

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 415 PM MST

* AT 315 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED
  A FEW SEVERE THUNDERSTORMS MOVING INTO THE PHOENIX EAST VALLEY...
  PARTICULARLY NEAR GILBERT...MESA...AND QUEEN CREEK. THUNDERSTORMS
  WERE MOVING NORTHEAST AT 20 MPH.

SEVERE THUNDERSTORMS COULD ALSO DEVELOP IN OTHER PARTS OF THE GREATER
PHOENIX AREA...INCLUDING GLENDALE...PEORIA...AND PARADISE VALLEY.

IF YOU ARE CAUGHT OUTSIDE...SEEK SHELTER FROM THE WEATHER IN A STRONG
BUILDING. DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...AND DEADLY
LIGHTNING ARE ALL POSSIBLE IN SEVERE THUNDERSTORMS. STAY INSIDE AWAY
FROM WINDOWS UNTIL THE STORM HAS PASSED.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WIND...LARGE HAIL...AND DEADLY LIGHTNING. PEOPLE OUTSIDE
SHOULD TAKE SHELTER...PREFERABLY IN A STRONG BUILDING AWAY FROM
WINDOWS.

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 3335 11235 3331 11216 3322 11207 3323 11161
          3346 11160 3345 11170 3371 11175 3376 11239

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 Sep 6, 10:10 AM MST, 5 hours 12 minutes earlier.

Area forecast discussion, Sep 6, 10:10 AM MST, 5 hours 12 minutes before
AZZ020>028-CAZ030>033-062245-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1010 AM MST FRI SEP 6 2002

.SYNOPSIS...
MOISTURE WILL CONTINUE TO FLOW INTO SOUTHEAST CALIFORNIA FROM THE
REMAINS OF TROPICAL SYSTEM HERNAN THE NEXT COUPLE OF DAYS...WITH
SOME MOISTURE FROM MEXICO MOVING OVER SOUTHWEST AND SOUTH-CENTRAL
ARIZONA. LOW PRESSURE ALOFT ALONG THE WEST COAST WILL GRADUALLY
SPREAD ADDITIONAL MOISTURE INTO SOUTHWEST AND SOUTH-CENTRAL
ARIZONA...FOR AN INCREASING CHANCE OF SHOWERS AND THUNDERSTORMS
TODAY TROUGH THIS WEEKEND. SOMEWHAT DRIER AIR WILL MOVE ACROSS THE
REGION THE FIRST PART OF NEXT WEEK. TEMPERATURES WILL LOWER THE NEXT
FEW DAYS TO NEAR OR SLIGHTLY BELOW AVERAGE FOR THIS TIME OF YEAR.

.DISCUSSION...
A VERY MOIST...UNSTABLE AIRMASS HAS BEEN IMPORTED INTO ALL OF THE
PHX FORECAST AREA THE PAST DAY OR SO...THANKS MOSTLY TO TD HERNAN.
EVEN FAR ERN CWFA IS NOW IN THE SOUP AND THIS MORE LIKELY JUST DUE
TO SLY FLOW BRINGING MEXICAN MOISTURE OUR WAY RATHER THAN MOISTURE
DIRECTLY FROM HERNAN. PHX 12Z SOUNDING VERY UNSTABLE WITH LOTS OF
AVAILABLE CAPE READY TO BE RELEASED. NOW...IF WE CAN JUST PUT OUR
FINGERS ON A TRIGGER. MODELS NOT MUCH HELP HERE...BUT WV LOOPS HINT
THERE MAY BE AT LEAST A COUPLE OF WEAK RIPPLES APPROACHING IN THE
SLY FLOW FROM NW MEXICO. SO...MEDIUM GRADE CHANCE POPS STILL APPEAR
IN ORDER. IN FACT...IN AFTERNOON PACKAGE...WILL CONSIDER KICKING
POPS INTO AREAL TERMS. MEANWHILE...OVER WRN CWFA...A NICE PERSISTENT
LINE OF SHOWERS AND TSTMS CONTINUES TO RUMBLE. HAVE BEEN HANDLING
THIS WITH NOWS...BUT IF WE CAN GET SOME GROUND TRUTH THAT WOULD
SUPPORT OUR ONE AND THREE HOUR PRECIP RADAR ESTIMATES OF OVER ONE
INCH...WE MAY EVENTUALLY NEED TO GO WITH A SMALL STREAM FLOOD
ADVISORY. AS YOU WOULD EXPECT...THIS SMALL SCALE AREA OF CONVERGENCE
NOT BEING HANDLED WELL AT ALL BY THE 12Z MODELS. ALL IN ALL...IT
LOOKS LIKE A VERY ACTIVE WEEKEND WX-WISE. CURRENT FORECASTS IN
PRETTY GOOD SHAPE...NO UPDATES FOR NOW.   ESTLE

.PSR...NONE.

In the hours before

Special weather statement, Sep 6, 1:09 PM MST, 2 hours 13 minutes before
AZZ020>028-CAZ030>033-070700-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
109 PM MST FRI SEP 6 2002

...A RISK OF STRONG THUNDERSTORMS AND HAZARDOUS WEATHER OVER ALL
OF SOUTH-CENTRAL AND SOUTHWEST ARIZONA...AS WELL AS SOUTHEAST
CALIFORNIA DESERTS THIS AFTERNOON AND EVENING...

THE OUTLOOK AREA CONSISTS OF THE FOLLOWING COUNTIES...
MARICOPA...NORTHERN PINAL...SOUTHERN GILA...LA PAZ AND YUMA IN
ARIZONA...AND IMPERIAL AND EASTERN RIVERSIDE COUNTIES IN SOUTHEAST
CALIFORNIA. CITIES AND TOWNS IN THE OUTLOOK AREA INCLUDE...THE
GREATER PHOENIX METROPOLITAN AREA...CASA GRANDE...FLORENCE...
COOLIDGE...GLOBE...MIAMI...SUPERIOR...GILA BEND...WENDEN...PARKER
...QUARTZSITE AND YUMA...AS WELL AS BLYTHE AND THE IMPERIAL VALLEY
TOWNS IN SOUTHEAST CALIFORNIA.

THE PRIMARY HAZARDOUS WEATHER RISKS OVER THIS OUTLOOK AREA INCLUDE
STRONG AND DAMAGING WIND IN EXCESS OF 45 MPH...AREAS OF BLOWING
DUST AND BRIEF HEAVY RAIN...ALONG WITH LIGHTNING.

STORM SPOTTER ACTIVATION MAY BE NECESSARY LATER THIS AFTERNOON.

ESTLE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 2:12 PM MSTSevere Thunderstorm WarningPSRMaricopa63 min
Sep 6, 3:26 PM MSTSevere Thunderstorm WarningPSRPinal64 min
Sep 6, 4:16 PM MSTSevere Thunderstorm WarningPSRMaricopa59 min
Sep 6, 4:17 PM MSTSevere Thunderstorm WarningPSRGila58 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.