Alert archive / Arizona / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 76, NWS Phoenix, AZ

September 4, 2003La Paz County, Arizona; Riverside County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 4, 2003, 9:03 PM MST for La Paz County, Arizona; Riverside County, California. It was in force for 57 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 4, 2003, 9:03 PM MST (04:03 UTC)
Expired
Sep 4, 2003, 10:00 PM MST
In force
57 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

Counties La Paz County, AZ, Riverside County, CA

The radar

The Yuma radar (KYUX), 156 km from the middle of the area, began a volume at 04:05 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, 4.1 hours before the alert went out and 216 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 2003-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 945 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 2003-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 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
945 J/kg
Mixed-layer CIN
-24 J/kg
Mixed-layer LCL
2381 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
21 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.

000 
WUUS55 KPSR 050403
SVRPSR
AZC012-CAC065-050500-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
901 PM MST THU SEP 4 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME NORTHEASTERN RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA
  CENTRAL LA PAZ COUNTY IN WEST CENTRAL ARIZONA

* UNTIL 1000 PM MST(1000 PM PDT)

* AT 855 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 8 MILES WEST OF BOUSE...OR ABOUT 19 MILES
  SOUTHEAST OF PARKER...MOVING SOUTHWEST AT 40 MPH.

* THE SEVERE THUNDERSTORM WILL AFFECT...
  QUARTZSITE
  BOUSE
  POSTON
  BRENDA 

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 3360 11455 3356 11377 3425 11367 3430 11440
          3381 11454

$$

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 4, 8:24 PM MST, 39 minutes earlier.

Area forecast discussion, Sep 4, 8:24 PM MST, 39 minutes before
AZZ020>028-CAZ030>033-051045-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX ARIZONA
824 PM MST THU SEP 4 2003

.SYNOPSIS...
AN INCREASE IN MOISTURE FROM THE GULF OF CALIFORNIA WILL CONTINUE A
A SLIGHT CHANCE OF SHOWERS AND THUNDERSTORMS OVER SOUTHEAST
CALIFORNIA...SOUTHWEST AND SOUTH CENTRAL ARIZONA...THROUGH FRIDAY
EVENING. HIGH PRESSURE ALOFT WILL MOVE FROM EASTERN ARIZONA TO NEAR
SAN DIEGO BY SATURDAY MORNING...WITH SOME DRYING AND A LITTLE WARMER
DAYTIME HIGHS OVER THE WEEKEND. STRONG UPPER LEVEL LOW PRESSURE WILL
MOVE INTO THE PACIFIC NORTHWEST LATE IN THE WEEKEND FOR MOSTLY CLEAR
SKIES AND NEAR NORMAL TEMPERATURES NEXT WEEK.

.DISCUSSION...
SEVERE WEATHER ACROSS SOUTHEAST CALIFORNIA...SOUTHWEST AND
SOUTH-CENTRAL ARIZONA HAS KEPT THE MAIN FOCUS THIS EVENING ON THE
CURRENT CONDITIONS...AND HAVENT HAD A CHANCE TO LOOK AT THE MODEL
DATA. STORMS THIS AFTERNOON/EVENING HAVE BEEN MOST INTENSE NEAR
IMPERIAL IN SOUTHEAST CALIFORNIA...OVER JOSHUA TREE NATIONAL
PARK...OVER THE EAST VALLEY IN CENTRAL MARICOPA COUNTY...AND NOW
NEAR GILA BEND IN SOUTHWEST MARICOPA COUNTY. A SMALL STREAM FLOOD
ADVISORY IS IN EFFECT FOR NORTHEAST MARICOPA COUNTY...INCLUDING
WICKENBURG...UNTIL 930PM...AND AN URBAN AND SMALL STREAM FLOOD
ADVISORY IS IN EFFECT FOR THE GREATER PHX METRO AREA UNTIL 9 PM.
SOME OF THE MOST INTENSE STORMS HAVE PRODUCED QUARTER SIZE HAIL
(NEAR BASELINE RD AND HARDY IN TEMPE)...AND RAINFALL AMOUNTS OVER 2
INCHES IN SOME PLACES WITH RUNNING WASHES AND CREEKS...AND EVEN
STREET FLOODING... ACROSS MUCH OF MARICOPA COUNTY AND IMPERIAL
COUNTY. AT THE CURRENT TIME...STORMS ARE MOST NUMEROUS NEAR PARKER
AND OVER SOUTHWEST MARICOPA COUNTY... JUST NORTHEAST OF GILA BEND.

AS DISCUSSED BY THE PREVIOUS FORECASTER...WILL HOLD ONTO A CHANCE
FOR AFTN/EVENING STORMS FRIDAY ALSO...AS HIGH MOVES TO OUR WEST AND
DEEP LAYERED LIGHT NORTH-NORTHWEST FLOW DEVELOPS. NOT SURE HOW
UNSTABLE IT WILL BE FRIDAY AFTN/EVENING...AS EVOLUTION OF STORMS
THIS EVENING IS NOT CLEAR CUT...BUT STILL A LOT OF CONVECTION TO OUR
SOUTH THIS AFTN...SO WOULD NOT BE SURPRISED TO SEE LOW LEVEL
MOISTURE REMAIN PLENTIFUL OVER OUR CWA THRU AT LEAST FRIDAY
EVENING...ALONG WITH AT LEAST LOW-END CAPE.

DRYING STILL EXPECTED TO COMMENCE IN LOW LEVELS BY SATURDAY...FROM
WEST TO EAST ACROSS THE CWA...AND WE WILL HAVE TO WATCH FOR THE
POSSIBILITY OF ISOLATED SEVERE STORMS SAT AFTN/EVENING...ESPECIALLY
OVER THE HIGHER TERRAIN NORTH AND EAST OF PHOENIX. FURTHER DRYING IS
EXPECTED NEXT WEEK AS DEEP WEST TO NORTHWEST FLOW DEVELOPS. UPPER
HIGH PROGGED TO REMAIN FAIRLY STRONG AND BE CENTERED NEAR OR JUST
SOUTH OF YUMA THIS WEEKEND...SO WENT WITH A BIT WARMER DAYTIME HIGHS
COMPARED TO WHAT WILL OCCUR FRIDAY. EXPECT A TREND TOWARD NEAR
NORMAL TEMPS TO BEGIN EARLY NEXT WEEK AS TROUGH DIGS INTO WESTERN
UNITED STATES...WITH 500 MB HEIGHTS LOWERING TO NEAR NORMAL LEVELS
BY TUESDAY.  LATEST GFS INDICATES SOMEWHAT PROGRESSIVE UPPER FLOW
EXPECTED TOWARD THE END OF NEXT WEEK...WITH A CHANCE FOR A BIT OF
WARMING BY THURSDAY AS HEIGHTS/THICKNESSES EDGE UPWARD.

.PSR...NONE.
Hazardous weather outlook, Sep 4, 1:00 PM MST, 8 hours 3 minutes before
AZZ020>028-CAZ030>033-050100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
100 PM MST THU SEP 4 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND
SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.
HOWEVER...ISOLATED STRONG THUNDERSTORMS ARE EXPECTED TO DEVELOP
MAINLY OVER THE HIGHER TERRAIN THIS AFTERNOON...WITH A FEW STRONG
STORMS POSSIBLE OVER THE LOWER DESERT. STORMS WILL MOVE VERY
SLOWLY...SO LOCALLY HEAVY RAIN WILL BE POSSIBLE. IN
ADDITION...STRONG GUSTY WINDS...HAIL...AND INTENSE CLOUD TO GROUND
LIGHTNING WILL ACCOMPANY THE STRONGEST STORMS.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.
HOWEVER...ISOLATED THUNDERSTORMS ARE EXPECTED TO AFFECT MAINLY SOUTH
CENTRAL ARIZONA FRIDAY AFTERNOON AND EVENING...WITH A CHANCE FOR
STORMS MAINLY OVER THE HIGHER TERRAIN OF SOUTH CENTRAL ARIZONA
SATURDAY AFTERNOON AND EVENING.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 4, 5:52 PM MSTSevere Thunderstorm WarningPSRMaricopa53 min
Sep 4, 6:09 PM MSTFlash Flood WarningPSRMaricopa36 min
Sep 4, 6:10 PM MSTSevere Thunderstorm WarningPSRMaricopa50 min
Sep 4, 6:41 PM MSTSevere Thunderstorm WarningPSRMaricopa64 min
Sep 4, 7:57 PM MSTSevere Thunderstorm WarningPSRLa Paz63 min
Sep 4, 8:41 PM MSTSevere Thunderstorm WarningPSRMaricopa64 min
Sep 4, 5:00 PM MSTSevere Thunderstorm WarningPSRImperial60 min
Sep 4, 5:31 PM MSTSevere Thunderstorm WarningPSRRiverside59 min
Sep 4, 5:44 PM MSTFlash Flood WarningPSRImperial2 hr
Sep 4, 6:48 PM MSTSevere Thunderstorm WarningPSRRiverside57 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2003Severe Thunderstorm Warnings in California, 2003Every severe thunderstorm warning in 2003

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.