Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 71, NWS Phoenix, AZ

September 27, 2002Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Sep 27, 2002, 8:59 PM MST for Maricopa County, Arizona. It was in force for 46 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 27, 2002, 8:59 PM MST (03:59 UTC)
Expired: Sep 27, 2002, 9:45 PM MST
In force: 46 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), 18 km from the middle of the area, began a volume at 04:00 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

Tuscon, AZ (KTUS), launched 00:00Z, 4.0 hours before the alert went out and 158 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: 196 J/kg
Mixed-layer CIN: -18 J/kg
Mixed-layer LCL: 3884 m above ground
0-6 km bulk shear: 24 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 5 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.

508 
WUUS55 KPSR 280359
SVRPSR
AZC013-280445-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
857 PM MST FRI SEP 27 2002

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 945 PM MST

* AT 850 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR
  INDICATED A SEVERE THUNDERSTORM JUST SOUTH OF   
  AHWATUKEE...MOVING NORTHEAST AT 25 MPH.

THIS STORM WILL AFFECT THE PHOENIX EAST VALLEY INCLUDING TEMPE...
CHANDLER...GILBERT...AND MESA.

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 3322 11208 3322 11177 3337 11168 3350 11162
          3351 11188

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 27, 6:39 PM MST, 2 hours 20 minutes earlier.

Area forecast discussion, Sep 27, 6:39 PM MST, 2 hours 20 minutes before

AZZ020>028-CAZ030>033-280545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION COR
NATIONAL WEATHER SERVICE PHOENIX AZ
351 PM MST FRI SEP 27 2002

CORRECTION FOR TIME OF ISSUANCE AND MESSAGE TERMINATION TIME

.SYNOPSIS...
A FAIRLY STRONG LOW PRESSURE SYSTEM ALOFT WILL BE ENTRENCHED OVER THE
WESTERN STATES THIS WEEKEND INTO NEXT WEEK. A SERIES OF DISTURBANCES
MOVING THROUGH THIS SYSTEM WILL BRING UNSETTLED WEATHER TO SOUTHEAST
CALIFORNIA AND SOUTHWEST ARIZONA AT TIMES THROUGH MUCH OF NEXT WEEK.
LOOK FOR A GRADUAL COOLING...WITH NEAR OR SLIGHTLY BELOW NORMAL HIGH
TEMPERATURES BY SUNDAY...WITH AFTERNOON HIGH TEMPERATURES EXPECTED
TO BE AT THEIR LOWEST ON WEDNESDAY AND THURSDAY. IN ADDITION...SOME
BREEZINESS AND CLOUDS ARE EXPECTED AT TIMES...ALONG WITH A POSSIBLE
SHOWER OR THUNDERSTORM. THE LOW PRESSURE SYSTEM WILL BECOME STRONGER
AND MORE DEFINED BY WEDNESDAY...BRINGING MORE COOLING...BREEZES AND
A GREATER THREAT OF SHOWERS AND THUNDERSTORMS.

.DISCUSSION...
FULL LATITUDE TROF OVER THE W WITH A SERIES OF EMBEDDED SHORT-WAVES
EXPECTED TO CONTINUE TO ROTATE THRU IT. STRONG RIDGE AROUND 140W
WILL KEEP THE TROF IN PLACE. HAVE DECIDED THE TREND SHOWN BY THE NEW
AVN...WITH A CLOSED LOW OVER SRN CA BY WED MORNING...IS THE WAY TO
GO. THE 00Z MRF NOT PROVIDING MUCH HELP...AS IT HAD THE LOW TOO FAR
E AND EJECTED IT TOO SOON IN MY OPINION..ABOUT 24 HRS TOO FAST. THE
WV IMAGERY SUPPORTS A DIGGING SCENARIO...AS IMPULSES SPLIT OVER THE
PAC NW AND SOME ENERGY DROPS SWD ALONG AND OFFSHORE OF THE W COAST.
THIS WILL TEND TO EJECT VORT IMPULSES ACROSS OUR AREA TONIGHT THRU
SUN FOR THREAT OF SHOWERS AND TSTMS...AS WE HAVE SEEN ON THE LOWER
DESERTS TODAY. RESPITE BY SUN NIGHT THRU TUE BEFORE THE TROF REALLY
DIGS IN AND WE END UP WITH A SIGNIFICANT SYSTEM MOVING ACROSS THE
REGION FROM W TO E WED AND THU. ADDED CHANCE SHOWERS AND TSTMS TO
THE ENTIRE CWA FOR THOSE DAYS. EXPECT THE LOW TO BE E OF OUR AREA ON
FRI FOR IMPROVED WEATHER AND WARMING. TEMPS WILL LIKELY BOTTOM OUT
ON WED OR THU...IN THE LOWER TO MID 80S ON THE DESERTS FOR HIGHS.

WILT

.PSR...NONE.

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.