Alert archive / Arizona / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 20, NWS Phoenix, AZ

July 21, 2000Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 21, 2000, 9:55 PM MST for Maricopa County, Arizona. It was in force for 45 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
Jul 21, 2000, 9:55 PM MST (04:55 UTC)
Expired
Jul 21, 2000, 10:40 PM MST
In force
45 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa County, AZ

The nearest sounding before it

Phoenix, AZ (KPSR), launched 00:00Z, 4.9 hours before the alert went out and 49 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 2000-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 676 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, Phoenix, AZ at 00:00Z on 2000-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
676 J/kg
Mixed-layer CIN
-223 J/kg
Mixed-layer LCL
2929 m above ground
0-6 km bulk shear
25 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
82 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.

186 
WUUS55 KPSR 220454
SVRPHX
AZC013-220540-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
955 PM MST FRI JUL 21 2000

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

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

* UNTIL 1040 PM MST

* AT 950 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 5 MILES WEST OF FOUNTAIN HILLS...MOVING
  SOUTHWEST 10 MPH.

* SOME LOCATION AFFECTED INCLUDE...
  FOUNTAIN HILLS
  PARADISE VALLEY
  SCOTTSDALE.

DAMAGING WINDS ARE LIKELY. GO INSIDE A STURDY BUILDING AND STAY AWAY
FROM WINDOWS REMEMBER...SEVERE THUNDERSTORMS HAVE THE POTENTIAL TO
PRODUCE TORNADOES.

CB

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 Jul 21, 9:40 PM MST, 15 minutes earlier.

Area forecast discussion, Jul 21, 9:40 PM MST, 15 minutes before
AZZ020>028-CAZ030>033-221045-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
940 PM MST FRI JUL 21 2000

.SYNOPSIS...
MONSOON MOISTURE HAS RETURNED TO MUCH OF THE DESERT SOUTHWEST...FOR
MORE HUMID CONDITIONS. THIS MEANS A THREAT OF MAINLY AFTERNOON
AND EVENING THUNDERSTORMS FOR SOUTH-CENTRAL AND SOUTHWEST ARIZONA
THE NEXT SEVERAL DAYS. STRONG HIGH PRESSURE WILL ALSO BE IN PLACE
OVER THE SOUTHWEST FOR TEMPERATURES AT OR ABOVE NORMAL.

.DISCUSSION...
OUTFLOW BOUNDARIES INTERACTING TO PRODUCE ISOLATED THUNDERSTORMS IN
SOUTH-CENTRAL ARIZONA INCLUDING THE PHOENIX AREA THIS EVENING. THERE
WAS ALSO A LARGE SYSTEM SOUTH OF THE BORDER MOVING WEST WITH A LOT OF
LIGHTNING. OUTFLOW FROM THIS SYSTEM WILL SPREAD MORE MOISTURE INTO
SOUTHERN ARIZONA OVERNIGHT AND THIS BOUNDARY INTERACTING WITH OTHER
OUTFLOW BOUNDARIES COULD KEEP AT LEAST ISOLATED THUNDERSTORMS GOING
BEYOND MIDNIGHT. IN ANY CASE...EXCEPT THE THREAT OF MAINLY AFTERNOON
AND EVENING THUNDERSTORMS TO CONTINUE OVER THE WEEKEND PER THE ABOVE
MENTIONED MOISTURE MOVING INTO THE AREA. SOUTH-CENTRAL ARIZONA DESERT
ZONES INCLUDING THE PHOENIX AREA WERE UPDATED AT 0335 GMT TO MENTION
ISOLATED EVENING THUNDERSTORMS.

ELLIS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 21, 7:41 PM MSTSevere Thunderstorm WarningPSRMaricopa59 min

Nearby

Severe Thunderstorm Warnings in Arizona, 2000Every severe thunderstorm warning in 2000

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.