Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 45, NWS Phoenix, AZ

August 29, 2001Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 29, 2001, 8:50 PM MST for Pinal County, Arizona. It was in force for 40 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued
Aug 29, 2001, 8:50 PM MST (03:50 UTC)
Expired
Aug 29, 2001, 9:30 PM MST
In force
40 min
Issued by
NWS Phoenix, AZ
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 39 km from the middle of the area, began a volume at 03:51 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.

What was reported inside it

TimeReportWhereRemark
Aug 29, 9:00 PM MSTHail 0.88Coolidge, AZ

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 3.8 hours before the alert went out and 106 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, Tuscon, AZ at 00:00Z on 2001-08-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 661 joules per kilogram.LCLEL10008507005003002001001 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, Tuscon, AZ at 00:00Z on 2001-08-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 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
661 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
2833 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
1 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.

206 
WUUS55 KPSR 300350
SVRPHX
AZC021-300430-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
850 PM MST WED AUG 29 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  CENTRAL PINAL COUNTY IN SOUTH CENTRAL ARIZONA

* UNTIL 930 PM MST

* AT 848 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM ABOUT 2 MILES SOUTHWEST OF COOLIDGE...MOVING
  NORTHEAST AT 10 MPH.

DAMAGING MICROBURST WINDS ARE LIKELY WITH THIS STORM. VERY HEAVY RAIN
IS ALSO POSSIBLE. TAKE COVER IN A SUBSTANTIAL SHELTER UNTIL THE STORM
PASSES.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WIND...LARGE HAIL...AND DEADLY LIGHTNING. PEOPLE OUTSIDE
SHOULD TAKE SHELTER...PREFERABLY IN A STRONG BUILDING AWAY FROM
WINDOWS.

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 3297 11159 3292 11152 3298 11141 3307 11152

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 29, 3:15 PM MST, 5 hours 35 minutes earlier.

Area forecast discussion, Aug 29, 3:15 PM MST, 5 hours 35 minutes before
AZZ020>028-CAZ030>033-300545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 PM MST WED AUG 29 2001

.SYNOPSIS...
WEAK UPPER LEVEL IMPULSES WILL BE MOVING ACROSS THE AREA THE NEXT
SEVERAL DAYS. HOWEVER...MOISTURE LEVELS WILL GENERALLY REMAIN
INADEQUATE TO GIVE RISE TO DAILY THUNDERSTORMS...EXCEPT FOR ACROSS
THE SOUTH-CENTRAL ARIZONA HIGHER TERRAIN THROUGH THURSDAY...AND AGAIN
OVER THE HOLIDAY WEEKEND. HIGH PRESSURE ALOFT WILL GRADUALLY BUILD
BACK OVER THE REGION NEXT WEEK...KEEPING MOST OF SOUTHWEST AND
SOUTH-CENTRAL ARIZONA AND SOUTHEAST CALIFORNIA DRY AND SEASONABLY
WARM.

.DISCUSSION...
SATELLITE PIX AND RADAR LOOPS WOULD SEEM TO INDICATE THAT THE CIN
PRESENT IN THIS MORNINGS SOUNDINGS WAS PREVENTING ANY CAPE FROM
BEING REALIZED. CU CLOUDS IN AND AROUND GTR PHX AREA ARE ABOUT AS
FLAT AS CAN BE. MEANWHILE...SURGE FROM THIS MORNING HAS WEAKENED
SOMEWHAT...ALTHOUGH SLY FLOW STILL EVIDENT ON KYUX VWP UP TO 5K.
SFC DEWPOINTS HAVE TAPERED OFF INVOF THE CO RIVER...WITH YUM MCAS
DOWN TO 63F FROM VALUES IN THE 70S EARLIER TODAY. STILL EXPECTING
SOME DYNAMICS ASSOCIATED WITH A WEAK 250MB JET TO MOVE CLOSE TO THE
AREA TONIGHT...BUT PROBABLY NOT STRONG ENOUGH TO INITIATE ANY
NOCTURNAL CONVECTION IN PHX CWFA...MAYBE FURTHER N. THEREFORE...WILL
LET ISOLATED TSTM CHANCES DIE OUT WITH THE SUNSET IN ZONE 24. 12Z
MODELS DOWNRAMPED THE MOISTURE SOMEWHAT...ESPECIALLY AT 500MB LEVEL
...ON THURSDAY AND INTO FRIDAY. WILL KEEP A LINGERING SLIGHT CHANCE
GOING IN ZONE 24 THU AFTERNOON/EVENING...DRY ELSEWHERE. AS MENTIONED
ABOVE...TEMPS HAVE BEEN STRUGGLING ALL DAY TO RISE TO NEAR
CONVECTIVE INITIATION VALUES...WITH DESERTS ONLY REACHING THE UPPER
90S TO NEAR 105...DOWN 5 TO 8 DEGREES FROM YESTERDAY. MODEL SOUNDINGS
DO NOT GIVE MUCH MORE COOLING THE NEXT COUPLE OF DAYS...SO WILL GO
WITH BASICALLY A PERSISTENCE TEMPERATURE FORECAST.

THE EXTENDED MODELS KEEP THE FLOW PATTERNS PRETTY WISHY-WASHY...WITH
NOTHING STRONG ENOUGH TO SCOUR OUT WHAT MOISTURE WE HAVE IN PLACE. SO
WILL LEAVE DAILY CHANCES FOR STORMS IN ZONE 24...NOWHERE ELSE. CAVEAT
TO THIS WOULD BE ANY MOISTURE INPUT FROM HURRICANE FLOSSIE. IF THAT
HAPPENS AND WE GET ANOTHER SURGE OR TWO OF MOISTURE...WOULD HAVE TO
CONSIDER EXPANDING TSTM THREATS FURTHER WEST IN THE CWFA OVER THE
HOLIDAY WEEKEND. WILL TAKE A WAIT-AND-SEE APPROACH NEXT FEW DAYS AND
SEE WHAT FLOSSIE HAS TO SAY ABOUT ALL THIS.     ESTLE

Nearby

Severe Thunderstorm Warnings in Arizona, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.