Alert archive / Arizona / Severe Thunderstorm Warnings in 2004

Severe Thunderstorm Warning 17, NWS Phoenix, AZ

July 23, 2004Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 23, 2004, 6:53 PM MST for Maricopa County, Arizona. It was in force for 22 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, 2004, 6:53 PM MST (01:53 UTC)
Expired
Jul 23, 2004, 7:15 PM MST
In force
22 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), 71 km from the middle of the area, began a volume at 01:54 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, 1.9 hours before the alert went out and 70 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 2004-07-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 247 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 2004-07-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 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
247 J/kg
Mixed-layer CIN
-262 J/kg
Mixed-layer LCL
2514 m above ground
0-6 km bulk shear
4 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
51 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 240153
SVRPSR
AZC013-240215-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
652 PM MST FRI JUL 23 2004

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHEASTERN MARICOPA COUNTY IN SOUTH CENTRAL ARIZONA...
  NEAR THE TOWN OF SUNFLOWER AND NEARBY HIGHWAY 87.

* UNTIL 715 PM MST

* AT 644 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN 
  EXCESS OF 60 MPH...AND LARGE HAIL.  THIS STORM WAS LOCATED NEAR 
  SUNFLOWER...OR ABOUT 22 MILES SOUTH OF PAYSON...AND MOVING 
  SOUTH AT 5 MPH.

* THE SEVERE THUNDERSTORM WILL OTHERWISE REMAIN OVER MAINLY RURAL
  AREAS OF THE INDICATED COUNTY.

LAT...LON 3399 11147 3392 11157 3380 11148 3384 11139

$$

HV

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, 3:24 PM MST, 3 hours 29 minutes earlier.

Area forecast discussion, Jul 23, 3:24 PM MST, 3 hours 29 minutes before
AZZ020>028-CAZ030>033-240545-

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM FRI JUL 23 2004

SOUTHWEST AND SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA
FORECAST DISCUSSION

.SYNOPSIS...
HIGH PRESSURE ALOFT WILL BE CENTERED OVER CENTRAL ARIZONA
TONIGHT...THEN WILL MOVE OVER NORTHERN ARIZONA THIS WEEKEND.
MEANWHILE...LOW PRESSURE SYSTEMS MOVING WEST ACROSS MEXICO AND THE
GULF OF CALIFORNIA WILL HELP INCREASE MOISTURE THROUGH THE WEEKEND.
THUS...AN INCREASING CHANCE OF MAINLY AFTERNOON AND EVENING SHOWERS
AND THUNDERSTORMS IS EXPECTED TONIGHT THROUGH THE WEEKEND...WITH THE
THREAT FOR THUNDERSTORMS SHIFTING TO MAINLY SOUTH-CENTRAL ARIZONA BY
THE MIDDLE OF NEXT WEEK AS A LOW PRESSURE SYSTEM DEVELOPS ALONG THE
CALIFORNIA COAST...AND PUSHES THE UPPER HIGH SOUTH TO NEAR THE
MEXICAN BORDER.

&&

.DISCUSSION...
NOT MUCH CHANGE FROM THE MORNING THINKING...STILL BELIEVE THAT THERE
WILL BE AN UPSWING IN CONVECTION TONIGHT INTO THE WEEKEND...WITH THE
CHANCES CONTINUING INTO THE MIDDLE OF NEXT WEEK. UPPER HIGH NOW
CENTERED JUST NORTH OF PHX WITH A WEAK NLY STEERING FLOW IN PLACE
OVER THE CENTRAL DESERTS. UPPER LEVEL SHORT WAVE MOVING EAST ACROSS
NRN AZ TONIGHT COMBINED WITH A PRONOUNCED INVERTED TROF APCHG SERN
AZ FROM NWRN MEXICO WILL GIVE STRONG DEFORMATION IN THE UPPER
ATMOSPHERE OVER SRN AZ TONIGHT...WITH THE STRONGEST DIFLUENCE ALOFT
OVER SERN AZ. 18Z PHOENIX RAOB QUITE WET AND UNSTABLE...WITH 1.7
INCH PWAT...AND SURFACE DEWPOINTS OVER THE SRN DESERTS ARE IN THE
UPPER 50S TO MID 60S. SCT STRONG STORMS FIRING OVER PARTS OF SERN AZ
AND ECNTRL AZ AT 3 PM...AND STORMS ALSO FORMING ALONG THE ERN RIM.
EXPECT THE CONVECTION OVER SERN AZ TO BLOSSOM THIS EVE AND SEND
OUTFLOWS TO THE N AND NW...WHICH COULD COMBINE WITH OUTFLOW FROM
STORMS TO OUR NORTH AND YIELD NEW THUNDERSTORMS OVER THE SCNTRL
DESERTS. HAVE UPPED OUR POPS AT PHOENIX TO THE CHANCE CATEGORY
TONIGHT AS A RESULT. WRN DESERTS AND SERN CA ARE DRIER WITH LESS
DYNAMICS...SO POPS WILL DECREASE STEADILY AS YOU MOVE WESTWARD.

BY SATURDAY...UPPER HIGH SETS UP OVER NWRN AZ OR SRN NEVADA...
PROVIDING A NLY TO NELY STEERING FLOW WHICH IS FAVORABLE FOR
ADVECTING RIM STORMS INTO THE SRN DESERTS. THERE SHOULD BE AMPLE LOW
AND MID LEVEL MOISTURE TO WORK WITH OVER OUR DESERTS...AS A GULF
SURGE WILL KEEP FEEDING MOISTURE UP THE LOWER CO RIVER VALLEY...AND
THE MID LEVEL ANTICYC GYRE WILL KEEP FEEDING THE MOISTURE EASTWARD
OVER OUR DESERTS. THUS THERE WILL BE A CHANCE FOR AFTERNOON AND EVE
STORMS OVER THE SCNTRL SAT THRU TUE...WITH A SLIGHT CHANCE OVER THE
WESTERN ZONES. LATEST GFS CONTINUES THE IDEA OF DEVELOPING TROFFING
AGAIN ALONG THE CA COAST MIDDLE OF NEXT WEEK INTO THE WEEKEND AND
THIS WOULD SET UP A SWLY FLOW INTO OUR WRN CWA. AS THIS OCCURS DRIER
AIR WOULD SPREAD INTO OUR WRN CWA...ESPECIALLY SERN CA...AND LIMIT
OR ELIMINATE ANY CHANCE FOR SHOWERS OR STORMS. THIS TREND IN THE
MODELS IS ACCEPTED AND NO CHANGES WILL BE MADE TO THE LAST FEW DAYS
OF THE FORECAST. ERN CWA WILL STILL HAVE A LEAST A SLIGHT CHANCE FOR
STORMS FROM WED THR FRI...AS MOISTURE WILL REMAIN IN THAT PART OF
THE FORECAST AREA.

.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.

&&

11
Hazardous weather outlook, Jul 23, 10:48 AM MST, 8 hours 5 minutes before
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
1048 AM MST FRI JUL 23 2004

AZZ024-240500-
SOUTHERN GILA/TONTO NF FOOTHILLS-
1048 AM MST FRI JUL 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTH CENTRAL ARIZONA.

.DAY ONE...TODAY

ISOLATED TO SCATTERED THUNDERSTORMS MAY CAUSE HEAVY RAINS AND
MINOR FLOODING OF POOR DRAINAGE AND LOW LYING AREAS. WASHES MAY BEGIN
FLOWING.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS AN CHANCE FOR THUNDERSTORMS SATURDAY THROUGH NEXT FRIDAY
WITH THE BEST THREAT FOR HEAVY RAINS...FLOODING...AND GUSTY
WINDS...EXPECTED SATURDAY THROUGH TUESDAY.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY THROUGH THURSDAY.

&&

FOR ADDITIONAL WEATHER INFORMATION...CHECK OUR WEB SITE AT
HTTP://WWW.WRH.NOAA.GOV/PHOENIX (IN SMALL LETTERS)

AZZ021>023-026>028-240500-
GREATER PHOENIX AREA-NORTHWEST AND NORTH CENTRAL PINAL COUNTY-
NORTHWEST MARICOPA COUNTY-SOUTHWEST DESERTS-
SOUTHWEST MARICOPA COUNTY-WEST CENTRAL DESERTS-
1048 AM MST FRI JUL 23 2004

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

.DAY ONE...TODAY

THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS TODAY...BUT THEY WILL
LIKELY NOT PRODUCE SEVERE WINDS...HEAVY RAIN OR FLOODING. GUSTY WINDS
TO 40 MPH...ALONG WITH BRIEF HEAVY RAIN AND SOME BLOWING DUST ARE
POSSIBLE WITH ANY STORMS.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS AN INCREASING CHANCE FOR THUNDERSTORMS SATURDAY THROUGH
TUESDAY...AND THEY MAY PRODUCE LOCALLY HEAVY RAINFALL...MINOR
FLOODING OF ROADS AND WASHES...AND STRONG GUSTY WINDS LEADING TO
BLOWING DUST. THE THREAT FOR THUNDERSTORMS IS EXPECTED TO DECREASE
FROM THE WEST WEDNESDAY THROUGH FRIDAY.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED SATURDAY THROUGH TUESDAY.

&&

FOR ADDITIONAL WEATHER INFORMATION...CHECK OUR WEB SITE AT
HTTP://WWW.WRH.NOAA.GOV/PHOENIX (IN SMALL LETTERS)

AZZ020-025-CAZ030>033-240500-
IMPERIAL COUNTY-JOSHUA TREE NATIONAL PARK-
LOWER COLORADO RIVER VALLEY AZ-LOWER COLORADO RIVER VALLEY CA-
RIVERSIDE COUNTY/EASTERN DESERTS-YUMA/MARTINEZ LAKE AND VICINITY-
1048 AM MST FRI JUL 23 2004

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHEAST CALIFORNIA AND THE
LOWER COLORADO RIVER VALLEY.

.DAY ONE...TODAY

NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.

.DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY

THERE IS A SLIGHT CHANCE FOR THUNDERSTORMS SATURDAY THROUGH
TUESDAY...MAINLY IN THE EVENING HOURS. THEY MAY PRODUCE GUSTY WINDS
TO OVER 40 MPH...ALONG WITH BRIEF HEAVY RAIN AND BLOWING DUST. THE
THREAT FOR THUNDERSTORMS WILL DECREASE FROM THE WEST BEGINNING
WEDNESDAY.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED SATURDAY THROUGH TUESDAY.

&&

FOR ADDITIONAL WEATHER INFORMATION...CHECK OUR WEB SITE AT
HTTP://WWW.WRH.NOAA.GOV/PHOENIX (IN SMALL LETTERS)

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 24, 4:46 PM MSTSevere Thunderstorm WarningPSRMaricopa59 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2004Every severe thunderstorm warning in 2004

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.