Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 40, NWS Phoenix, AZ

August 28, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 28, 2002, 5:24 PM MST for Maricopa County, Arizona. It was in force for 66 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: Aug 28, 2002, 5:24 PM MST (00:24 UTC)
Expired: Aug 28, 2002, 6:30 PM MST
In force: 66 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), 42 km from the middle of the area, began a volume at 00:24 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, 0.4 hours before the alert went out and 50 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: 888 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 2880 m above ground
0-6 km bulk shear: 48 kt
0-1 km storm-relative helicity: 42 m²/s²
0-3 km storm-relative helicity: 104 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.6

Open this sounding in Storm Lab

The text

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

944 
WUUS55 KPSR 290024
SVRPSR
AZC013-290130-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
521 PM MST WED AUG 28 2002

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 630 PM MST

* AT 523 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED   
SEVERE THUNDERSTORMS FROM FOUNTAIN HILLS TO THE APACHE TRAIL. THE 
AREA OF SEVERE THUNDERSTORMS WAS MOVING TOWARD THE NORTHEAST AT 35 
MPH.

DAMAGING MICROBURST WINDS...VERY HEAVY RAIN...AND LARGE HAIL ARE 
LIKELY WITH THESE STORMS. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL 
THE STORM PASSES.  

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 3359 11170 3349 11161 3349 11136 3352 11110
          3368 11133 3394 11147 3382 11170

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 Aug 28, 3:55 PM MST, 1 hour 29 minutes earlier.

Area forecast discussion, Aug 28, 3:55 PM MST, 1 hour 29 minutes before

AZZ020>028-CAZ030>033-290545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
355 PM MST WED AUG 28 2002

.SYNOPSIS...
LOW PRESSURE OVER NEVADA...AND HIGH PRESSURE OVER SONORA MEXICO HAS
MADE FOR A PREDOMINATE SOUTHWEST WIND FLOW ALOFT...IN SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA...WHERE DRY WEATHER AND PLENTY OF
SUNSHINE WILL PREVAIL FOR THE NEXT SEVERAL DAYS.  A MOIST SOUTHERLY
WIND IN SOUTH CENTRAL ARIZONA CONTINUES TO BRING MONSOON MOISTURE
INTO EAST CENTRAL ARIZONA THAT SHOULD CONTINUE THE CHANCE FOR
SHOWERS AND THUNDERSTORMS THROUGH THE HOLIDAY WEEKEND AND INTO NEXT
WEEK.

.DISCUSSION...
THIS EVENING...JUST ENOUGH SHEAR...15 KTS TO 65 KTS BTWN LOW AND MID
LVLS ALONG WITH MID LVL MOISTURE AND CAPE GREATER THAN 1500 J/KG
EAST OF PHX AND SRN GILA COUNTY TO TRIGGER LATE AFTN STRONG CNVCTN.
THIS ACTIVITY SHD CONT THROUGH THE EVENING HOURS.  THE OVERALL
PATTERN WILL NOT CHANGE MUCH OVER THE NEXT FEW DAYS...DRY TO THE
WEST AND MODERATELY MOIST AND UNSTBL TO THE EAST...SO THE FCST IS
BASICALLY PERSISTANCE.  MAX AND MIN TEMPERATURES NEARLY STEADY
THROUGH THE NEXT SEVEN DAYS...MODERATED SOMEWHAT DUE TO THE HIGHER
HUMIDITY IN THE EASTERN PORTION OF THE CWA. RUNYAN

.PSR...NONE.

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 28, 5:07 PM MST	Severe Thunderstorm Warning	PSR	Maricopa	53 min
Aug 28, 6:48 PM MST	Severe Thunderstorm Warning	PSR	Maricopa, Pinal	57 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.