Alert archive / Arizona / Severe Thunderstorm Warnings in 2002

Severe Thunderstorm Warning 41, NWS Phoenix, AZ

August 28, 2002Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 28, 2002, 6:48 PM MST for Maricopa County, Pinal County, Arizona. 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 counties it named.

The facts

Issued
Aug 28, 2002, 6:48 PM MST (01:48 UTC)
Expired
Aug 28, 2002, 7:45 PM MST
In force
57 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 29 km from the middle of the area, began a volume at 01:51 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, 1.8 hours before the alert went out and 34 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 2002-08-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 888 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 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 2002-08-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 square meters per square second.19395878Sfc1 km3 km6 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
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

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, 2 hours 53 minutes earlier.

Area forecast discussion, Aug 28, 3:55 PM MST, 2 hours 53 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.

IssuedProductOfficeCountiesLasted
Aug 28, 5:07 PM MSTSevere Thunderstorm WarningPSRMaricopa53 min
Aug 28, 5:24 PM MSTSevere Thunderstorm WarningPSRMaricopa66 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.