Alert archive / Arizona / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 16, NWS Phoenix, AZ

August 4, 2001Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 4, 2001, 7:14 PM MST for Pinal County, Arizona. It was in force for 46 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 4, 2001, 7:14 PM MST (02:14 UTC)
Expired
Aug 4, 2001, 8:00 PM MST
In force
46 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), 38 km from the middle of the area, began a volume at 02:17 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 4, 7:45 PM MSTThunderstorm Wind 60 ESuperior, AZSevere thunderstorm wind gusts blew down trees in town.

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, 2.2 hours before the alert went out and 132 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 2001-08-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 875 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, Tuscon, AZ at 00:00Z on 2001-08-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -8 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
875 J/kg
Mixed-layer CIN
-84 J/kg
Mixed-layer LCL
2553 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
-8 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.1

Open this sounding in Storm Lab

The text

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

000 
WUUS55 KPSR 050216
SVRPHX

AZC021-050300-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
714 PM MST SAT AUG 4 2001

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTH CENTRAL PINAL COUNTY IN SOUTH CENTRAL ARIZONA...
  INCLUDING THE TOWNS OF SUPERIOR...FLORENCE JUNCTION...
  AND QUEEN VALLEY.

* UNTIL 800 PM MST

* AT 715 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR DETECTED A
  SEVERE THUNDERSTORM 8 MILES SOUTH OF SUPERIOR...MOVING NORTHWEST 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.

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 3343 11145 3310 11137 3315 11091 3347 11111

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 4, 3:00 PM MST, 4 hours 14 minutes earlier.

Area forecast discussion, Aug 4, 3:00 PM MST, 4 hours 14 minutes before
AZZ020>028-CAZ030>033-050545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
300 PM MST SAT AUG 4 2001

.SYNOPSIS...
STRONG HIGH PRESSURE OVER THE CENTRAL UNITED STATES WILL MOVE WEST
AND BE CENTERED OVER WYOMING EARLY NEXT WEEK. THE FLOW AROUND THIS
SYSTEM...COUPLED WITH ABUNDANT MOISTURE...WILL RESULT IN AFTERNOON
AND NIGHTTIME THUNDERSTORMS OVER SOUTH-CENTRAL ARIZONA AND PART OF
SOUTHWEST ARIZONA THROUGH THE MIDDLE OF NEXT WEEK. THERE WILL BE A
SLIGHT CHANCE OF STORMS IN SOUTHEAST CALIFORNIA SUNDAY AND SUNDAY
NIGHT...BEFORE SOME DRIER AIR BEGINS TO PUSH IN FROM THE WEST ONCE
AGAIN.

.DISCUSSION...
RAISED POPS IN PART OF S-CNTRL AZ FOR TONIGHT IN DEFERENCE TO THE
INCREASED POTENTIAL FOR STORMS. THE MOISTURE GRADIENT IS QUITE TIGHT
ACROSS S-CNTRL AZ. DRIER AIR HAS INTRUDED FROM THE W AND IS BUTTING
UP AGAINST THE MOIST AIR IN PLACE OVER CNTRL AND ERN AZ...NOT TOO
FAR W OF THE PHX METRO AREA. DEWPOINT AT GILA BEND WAS 41 DEG AT 21Z
...WITH LOW TO MID 60S JUST E OF THERE. MOISTURE EXPECTED TO SLOWLY
PUSH BACK WWD TONIGHT AS FLOW IS CHANGING FROM SLY TO MORE ELY OVER
SRN AZ. WE WILL HAVE TO WATCH STORMS FROM THE S AND SE...AS WELL AS
ANY BACK-BUILDING STORMS ALONG THE NRN BORDER OF THE CWA. THE SEVERE
POTENTIAL IS HIGHER TODAY THAN RECENTLY...WITH STRONG WIND THE MAIN
THREAT...WITH A SECONDARY THREAT OF HEAVY RAINFALL AND SLOW-MOVING
STORMS. WILL HAVE TO WATCH FOR FFW POSSIBILITIES AS WELL. HEAVY RNFL
JUST N OF OUR CWA MAY LEAD TO HEAVY RUNOFF INTO OUR CWA...SO THAT IS
A CONCERN AS WELL AND WILL HAVE TO BE MONITORED. ALSO...THERE WILL
BE A NUMBER OF OUTFLOW BOUNDARY INTERACTIONS IN THE CNTRL AND ERN
PORTIONS OF THE CWA THIS EVENING...LIKELY ENHANCING SEVERE POTENTIAL
AS WELL AS LEADING TO A THREAT OF BLOWING DIUST. EXPECT A RUN-OF-THE
-MILL CONVECTIVE DAY THIS AREA TOMORROW...HOWEVER...DO LOOK FOR A
POSSIBILITY OF ISOLATED STORMS FINALLY GETTING INTO FAR WRN PORTIONS
OF THE CWA AS A WEAKENING INVERTED TROUGH MOVES ACROSS NRN MEX AND
BRUSHES THAT AREA. IN THE EXTENDED...WILL KEEP A CHANCE OF STORMS
INTO THU MOST AREAS OF S-CNTRL AZ...THRU SAT HIGHER TERRAIN. DRIER
AIR COMING IN TO SLOW THINGS DOWN AGAIN FRI AND SAT AS ANOTHER ERN
PAC TROUGH MAKES ITS PRESENCE FELT BY TURNING THE FLOW SWLY OVER A
GOODLY PORTION OF THE CWA AND PROVIDING SOME COOLING AS THE HEIGHTS
COME DOWN]. WILL KEEP A CHANCE OF STORMS GOING IN THE HIGHER TERRAIN
OF ZONE 24 THRU THE EXTENDED...AS MOISTURE WILL LINGER THERE.  WILT

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 6:40 PM MSTSevere Thunderstorm WarningPSRGila, Maricopa50 min

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.