Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 52, NWS Phoenix, AZ

September 7, 2002La Paz County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 7, 2002, 2:38 PM MST for La Paz County, Arizona. It was in force for 37 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 7, 2002, 2:38 PM MST (21:38 UTC)
Expired
Sep 7, 2002, 3:15 PM MST
In force
37 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

County La Paz County, AZ

The radar

The Yuma radar (KYUX), 160 km from the middle of the area, began a volume at 21:42 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Sep 7, 1:30 PM MSTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 9.6 hours before the alert went out and 165 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 2002-09-07Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 146 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 2002-09-07The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 38 square meters per square second.19395878Sfc1 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
146 J/kg
Mixed-layer CIN
-210 J/kg
Mixed-layer LCL
1553 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
38 m²/s²
0-3 km storm-relative helicity
62 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.

268 
WUUS55 KPSR 072138
SVRPSR
AZC012-072215-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
234 PM MST SAT SEP 7 2002

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EAST CENTRAL LA PAZ COUNTY IN WEST CENTRAL ARIZONA

* UNTIL 315 PM MST

* AT 227 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  SEVERE THUNDERSTORMS 17 MILES SOUTHEAST OF BRENDA NOVING NORTHEAST
  AT 15 TO 20 MPH. AT 235 PM THESE STORMS WERE CROSSING INTERSTATE
 10 NEAR MILE MARKER 53...MOVING TOWARD SALOME AND WENDEN. 

THESE STORMS ARE CAPABLE OF PRODUCING DAMAGING WINDS TO 60 MPH.

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.

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 3358 11403 3343 11336 3395 11338 3397 11380

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 7, 10:25 AM MST, 4 hours 13 minutes earlier.

Area forecast discussion, Sep 7, 10:25 AM MST, 4 hours 13 minutes before
AZZ020>028-CAZ030>033-072245-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
1025 AM MST SAT SEP 7 2002

.SYNOPSIS...
MOIST UNSTABLE AIR WILL REMAIN IN PLACE OVER FAR SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA THE NEXT FEW DAYS. UPPER LEVEL
WINDS WILL REMAIN STRONGER THAN NORMAL SINCE LOW PRESSURE WILL
REMAIN JUST WEST OF THE AREA WHILE A RIDGE OF HIGH PRESSURE REMAINS
CENTERED OVER NEW MEXICO. A SERIES OF WEATHER DISTURBANCES WILL
BRING PERIODS OF SHOWERS AND THUNDERSTORMS TO THE AREA...WITH THE
GREATEST CHANCE FOR STORMS AND LOCALLY HEAVY RAIN OVER SOUTH-CENTRAL
ARIZONA. SOMEWHAT DRIER AIR MAY MOVE INTO SOUTHEAST CALIFORNIA AND
SOUTHWEST ARIZONA BY THE MIDDLE OF NEXT WEEK. TEMPERATURES WILL BE
NEAR SEASONAL NORMALS THE NEXT FEW DAYS.

.DISCUSSION...
ACTIVE WEATHER PATTERN REMAINS IN PLACE OVER THE FORECAST AREA THIS
MORNING. ABUNDANT MOISTURE EXISTS PER GOES PW IMAGES AND MORNING
SOUNDINGS...WITH PW 1.5-1.75. RATHER STRONG MID-UPPER LEVEL
DISTURBANCE OVER SOUTHEAST CALIFORNIA-FAR SOUTHERN NEVADA IS LIFTING
TOWARD THE NORTHEAST...WITH LOW-MID LEVEL CONVERGENCE ON TAIL END OF
DISTURBANCE OVER SOUTHWEST AZ ATTM. ASSOCIATED ASCENT WITH THIS
DISTURBANCE HAS ALREADY LED TO INTENSE THUNDERSTORM DEVELOPMENT
...WITH ISOLATED SEVERE STORMS CURRENTLY AFFECTING PORTIONS OF
NORTHWEST MARICOPA COUNTY. APPEARS THIS PARTICULAR AREA OF STORMS
WILL REMAIN PRIMARILY TO THE NORTHWEST OF THE GREATER PHOENIX
AREA...BUT MORE STORMS WILL BE DEVELOPING OVER THE AREA TODAY.
NEARLY THE ENTIRE PHX AREA RECEIVED MEASURABLE RAIN FRIDAY AFTERNOON
AND NIGHT...AND MORNING PHX SOUNDING WAS MUCH COOLER IN LOWER LEVELS
...WHICH HAS RESULTED IN MUCH LOWER CAPE. HOWEVER...WITH UPPER LEVEL
FORCING...ABUNDANT MOISTURE...AND EXPECTED DAYTIME HEATING INTO THE
MID 90S...SEE NO NEED TO BACK OFF FROM INHERITED FORECAST...
INCLUDING FLASH FLOOD WATCH FOR SOUTH CENTRAL AZ THIS AFTERNOON
THROUGH MIDNIGHT...AND THREAT FOR SEVERE THUNDERSTORMS WILL BE
PRESENT AS WELL TODAY AND THIS EVENING. DG

.PSR...FLASH FLOOD WATCH NOON TODAY THROUGH MIDNIGHT TONIGHT FOR S
CENTRAL AZ...MARICOPA...N CENTRAL PINAL...AND SOUTHERN GILA COUNTIES
...FCST AZ ZONES...22...23...24...27...AND 28.

In the hours before

Special weather statement, Sep 7, 11:30 AM MST, 3 hours 8 minutes before
AZZ021>024-026>028-080000-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
1130 AM MST SAT SEP 7 2002

...A RISK OF STRONG THUNDERSTORMS AND HAZARDOUS WEATHER OVER
PORTIONS OF SOUTHWEST AND SOUTH-CENTRAL ARIZONA THIS AFTERNOON AND
EVENING...

THE OUTLOOK AREA CONSISTS OF THE FOLLOWING COUNTIES IN ARIZONA...
MARICOPA...NORTHERN PINAL...SOUTHERN GILA...LA PAZ AND YUMA. CITIES
AND TOWNS IN THE OUTLOOK AREA INCLUDE...THE GREATER PHOENIX
METROPOLITAN AREA...CASA GRANDE...FLORENCE...COOLIDGE...GILA BEND...
WICKENBURG...WENDEN...AND DATELAND.

THE PRIMARY HAZARDOUS WEATHER RISK OVER THIS OUTLOOK AREA IS
LOCALLY HEAVY RAIN. A FLASH FLOOD WATCH HAS BEEN POSTED FOR SOUTH
CENTRAL ARIZONA FROM NOON UNTIL MIDNIGHT TONIGHT. IN ADDITION
TO HEAVY RAIN...LARGE HAIL...STRONG AND DAMAGING WINDS IN EXCESS OF
50 MPH...AND AREAS OF BLOWING DUST THAT COULD LOWER VISIBILITY TO
UNDER ONE HALF MILE WILL BE POSSIBLE WITH AND NEAR THE STRONGEST
STORMS.

STORM SPOTTER ACTIVATION MAY BE NECESSARY THIS AFTERNOON AND
EVENING.

DG

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 6, 5:15 PM MSTSevere Thunderstorm WarningPSRMaricopa45 min
Sep 6, 7:08 PM MSTSevere Thunderstorm WarningPSRMaricopa37 min
Sep 6, 7:13 PM MSTSevere Thunderstorm WarningPSRMaricopa32 min
Sep 6, 11:19 PM MSTSevere Thunderstorm WarningPSRMaricopa56 min
Sep 7, 10:13 AM MSTSevere Thunderstorm WarningPSRMaricopa47 min
Sep 7, 2:45 PM MSTSevere Thunderstorm WarningPSRPinal45 min
Sep 7, 3:14 PM MSTSevere Thunderstorm WarningPSRLa Paz46 min
Sep 7, 3:27 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal48 min
Sep 7, 3:57 PM MSTTornado WarningPSRMaricopa48 min
Sep 7, 3:57 PM MSTTornado WarningPSRMaricopa48 min
Sep 7, 4:08 PM MSTSevere Thunderstorm WarningPSRPinal37 min
Sep 7, 4:43 PM MSTSevere Thunderstorm WarningPSRMaricopa47 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.