Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 50, NWS Phoenix, AZ

September 6, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 6, 2002, 11:19 PM MST for Maricopa County, Arizona. It was in force for 56 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, 11:19 PM MST (06:19 UTC)
Expired: Sep 7, 2002, 12:15 AM MST
In force: 56 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), 109 km from the middle of the area, began a volume at 06:21 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 00:00Z, 6.3 hours before the alert went out and 92 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: 129 J/kg
Mixed-layer CIN: -74 J/kg
Mixed-layer LCL: 2528 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: -7 m²/s²
0-3 km storm-relative helicity: 34 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.

440 
WUUS55 KPSR 070619
SVRPSR
AZC013-070715-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
1117 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 1215 AM MST

* AT 1111 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 12 MILES SOUTHWEST OF GILA BEND...MOVING   
NORTHEAST AT 20 MPH. DAMAGING HIGH WINDS TO 60 MPH IS LIKELY WITH 
THIS STORM.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  GILA BEND AT 1140 PM MST

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 3287 11304 3264 11269 3305 11228 3331 11279

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, 9:35 PM MST, 1 hour 44 minutes earlier.

Area forecast discussion, Sep 6, 9:35 PM MST, 1 hour 44 minutes before

AZZ020>028-CAZ030>033-071045-

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

.SYNOPSIS...
MOIST SOUTHERLY WINDS...AND AN UNSTABLE AIRMASS OVER SOUTHEAST
CALIFORNIA...SOUTHWEST AND SOUTH CENTRAL ARIZONA WILL CONTINUE THE
CHANCE OF SHOWERS AND THUNDERSTORMS THROUGH THE WEEKEND.  A TROUGH
OF LOW PRESSURE ALONG THE CALIFORNIA COAST...AND A RIDGE OF HIGH
PRESSURE OVER NEW MEXICO...WILL REMAIN STATIONARY THROUGH SUNDAY.
EARLY NEXT WEEK...SOME DRIER AIR MAY MOVE INTO SOUTHEAST
CALIFORNIA...BUT MOIST AND UNSTABLE AIR REMAINS ANCHORED OVER
SOUTHERN ARIZONA FOR MOST OF NEXT WEEK.  TEMPERATURES WILL FALL
OFF TO NEAR SEASONAL NORMALS THE NEXT FEW DAYS.

.DISCUSSION...
INCREASING TROPICAL MOISTURE FROM OLD HURRICANE HERNAN SPREADS INTO
SOUTH CENTRAL AZ TNGT. RESULTING IN A REGENERATION OF SHOWERS AND
THUNDERSTORMS...SOME WITH HEAVY RAIN. THE REPEAT OF STORMS...GIVES
RISE TO THE POTENTIAL OF FLASH FLOODING OF LOW LYING AREAS...
NORMALLY DRY WASHES AND STREAM BEDS.  THUS...A FLASH FLOOD WATCH
HAS BEEN ISSUED AND IS IN EFFECT UNTIL 6 AM SATURDAY MORNING.

CONVECTION WITH BOUNDARY OUTFLOW INTERACTIONS AND DOWNBURST DAMAGE
IN THE PHOENIX AREA HAS APPARENTLY SUBSIDED IN THE PAST HOUR.
HOWEVER...NUMEROUS TSTMS CONTINUE WITH LOCAL RAINFALL AMOUNTS
EXCEEDING AN INCH IN ONE TO TWO HOURS.  SEE NO CHANGE AS THE
POSITION OF THE WEST COAST TROF AND THE LARGE RIDGE TO THE EAST
LOOKS TO BE STAGNANT.  MOIST SOUTHERLY FLOW INTO XTRM SE CA AND SW
AZ...WILL CONTINUE INTO THE WEEKEND...BRINGING PCPN TO SOME
LOCATIONS IN SW AZ...THE FIRST PCPN SINCE ISOLD TSTMS LAST JULY.
SOME LCTNS IN SE CA AND SW AZ HAS NOT SEEN PCPN SINCE LAST FALL.

THE POSITION OF THE WEST COAST TROUGH WILL PRODUCE A PROLONGED SW/NE
ORIENTED JET OVER SW AND S CNTRAL AZ...A FAVORABLE RIGHT ENTRANCE
REGION FROM LATE SAT NIGHT INTO EARLY MONDAY...STRONG CONVECTION
LIKELY. A SECONDARY LOW FORMING OFF THE SRN CA COST WILL HELP TO
KEEP MOISTURE IN PLACE OVER AZ PSBLY INTO NEXT WEEK...SO STORM
CHANCES KP GOING IN S CENTRAL AZ THRU THE MIDDLE OF NEXT WEEK...AND
HIGHER TERRAIN ZONE 24 RIGHT ON THRU FRIDAY OF NEXT WEEK. TEMPS SHD
SETTLE DOWN NEAR OR SLIGHTLY BELOW SEASONAL NORMALS. RUNYAN

.PSR...FLASH FLOOD WATCH REST OF TONIGHT THROUGH 6 AM SATURDAY
MORNING FOR S CENTRAL AZ...MARICOPA...N CENTRAL PINAL...AND SOUTHERN
GILA COUNTIES...FCST ZONES...22...23...24...27...AND 28.

In the hours before

Local storm report, Sep 6, 6:53 PM MST, 4 hours 26 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX, AZ
653 PM MST FRI SEP 6 2002

TIME(MST)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0305 PM    GLENDALE                  AZ   WIND DAMAGE
09/06/02   MARICOPA                       MICROBURST. SIGNIFCANT
                                          DAMAGE TO 15 TO 25 MOBILE
                                          HOMES. ROOF RIPPED OFF CAR
                                          DEALERSHIP. UP TO 100
                                          VEHICLES DAMAGED. NUMEROUS
                                          TREES AND POWER LINES DOWN.
                                          NO KNOWN INJURIES. REPORTED
                                          BY SPOTTERS AND MEDIA.

0232 PM    CHANDLER                  AZ   DUST STORM
09/06/02   MARICOPA                       VISIBILITY 1/4 MILE
                                          REPORTED AT CHANDLER
                                          REGIONAL AIRPORT.

0323 PM    FLORENCE                  AZ   DUST STORM
09/06/02   PINAL                          VISIBILITY REDUCED TO 50
                                          YARDS. REPORTED BY LAW
                                          ENFORCEMENT.

0340 PM    10 E APACHE JUNCTION      AZ   WIND DAMAGE
09/06/02   PINAL                          MICROBURST. GOLD CANYON
                                          RANCH AREA. AT LEAST 30
                                          POWER POLES DOWN. CHILDREN
                                          TRAPPED IN A SCHOOL FOR A
                                          TIME. ROOF DAMAGE. NO KNOWN
                                          INJURIES. REPORTED BY
                                          SPOTTERS AND MEDIA.

0346 PM    APACHE JUNCTION           AZ   60 MPH TSTM WIND GUST
09/06/02   PINAL                          REPORTED BY SPOTTERS

0430 PM    BUCKEYE                   AZ   WIND DAMAGE
09/06/02   MARICOPA                       POWER POLES DOWN. REPORTED
                                          BY ARIZONA PUBLIC SERVICE

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 6, 5:15 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	45 min
Sep 6, 7:08 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	37 min
Sep 6, 7:13 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	32 min
Sep 7, 10:13 AM MST	Severe Thunderstorm Warning	PSR	Maricopa	47 min
Sep 7, 2:38 PM MST	Severe Thunderstorm Warning	PSR	La Paz	37 min
Sep 7, 2:45 PM MST	Severe Thunderstorm Warning	PSR	Pinal	45 min
Sep 7, 3:14 PM MST	Severe Thunderstorm Warning	PSR	La Paz	46 min
Sep 7, 3:27 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	48 min
Sep 7, 3:57 PM MST	Tornado Warning	PSR	Maricopa	48 min
Sep 7, 3:57 PM MST	Tornado Warning	PSR	Maricopa	48 min
Sep 7, 4:08 PM MST	Severe Thunderstorm Warning	PSR	Pinal	37 min
Sep 7, 4:43 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	47 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.