Alert archive / Arizona / Tornado Warnings in 1999

Tornado Warning 1, NWS Phoenix, AZ

July 6, 1999Pinal County, Arizona

NWS Phoenix, AZ issued this tornado warning at Jul 6, 1999, 3:21 PM MST for Pinal County, Arizona. It was in force for 34 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 6, 1999, 3:21 PM MST (22:21 UTC)
Expired
Jul 6, 1999, 3:55 PM MST
In force
34 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Pinal County, AZ

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Jul 6, 1:15 PM MSTSevere Thunderstorm WatchSPC7 hr

The nearest sounding before it

Phoenix, AZ (KPSR), launched 12:00Z, 10.4 hours before the alert went out and 82 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 12:00Z on 1999-07-06Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 236 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 12:00Z on 1999-07-06The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -41 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
236 J/kg
Mixed-layer CIN
-208 J/kg
Mixed-layer LCL
2182 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
-41 m²/s²
0-3 km storm-relative helicity
-2 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.

000 
TTAA00 KPHX 062223 RRA
TORPHX
AZC021-062255-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
321 PM MST TUE JUL 6 1999

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL PINAL COUNTY IN CENTRAL ARIZONA

* UNTIL 355 PM MST

* AT 315 PM... SPOTTERS INDICATED A TORNADO NEAR FLORENCE JUNCTION...
  MOVING WEST AT 20 MPH.  THE TORNADO WILL MOVE WEST TOWARD GOLD
  CANYON

A TORNADO IS ON THE G\ROUND! GO TO THE BASEMENT! IF A BASEMENT IS
NOT AVAILABLE...GO TO A SMALL INTERIOR ROOM ON THE LOWEST FLOOR!

HV


&

What forecasters said that day

The local office's own words before this tornado 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 tornado warning went out at Jul 6, 2:50 PM MST, 31 minutes earlier.

Area forecast discussion, Jul 6, 2:50 PM MST, 31 minutes before
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
250 PM MST TUE JUL 6 1999

.SYNOPSIS...
HIGH PRESSURE ALOFT WILL REMAIN OVER THE COLORADO AND 4 CORNERS AREA
THROUGH THIS WEEK. THIS WILL KEEP A MOIST SOUTHEAST TO EASTERLY FLOW
OVER THE REGION WHICH WILL SPREAD THE MOISTURE WESTWARD. AS A RESULT
SKIES WILL REMAIN PARTLY CLOUDY OVER THE REGION WITH SCATTERED
AFTERNOON AND EVENING THUNDERSTORMS IN SOUTH CENTRAL ARIZONA BECOMING
ISOLATED IN SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA.

.DISCUSSION...
MODELS KEEP UPPER HIGH OVER COLORADO / 4 CORNERS AREA FOR NEXT FEW
DAYS. THIS KEEPS MOIST SOUTHEAST TO EAST FLOW OVER REGION. SATELLITE
PHOTOS SHOW THAT MOISTURE HAS ALREADY SPREAD INTO SW AZ AND PORTIONS
OF SE CA TODAY. IN ADDITION...A 4,000 FT. DEEP GULF SURGE OCCURRED
INT0 YUMA TODAY. MODELS SHOW COUPLE VORMAXS OVER THE NORTHERN GULF
WHICH MODELS TAKE A PIECE OF AND ROTATE INTO THE JOSHUA TREE AREA
TONIGHT/WEDNESDAY WITH SOME PVA EXTENDING UP INTO SW/SOUTH CENTRAL
AZ. THIS SHOULD HELP TO DEVELOP A THUNDERSTORMS TONIGHT OVER CENTRAL
DESERTS AND POSSIBLY ISOLATED IN SW AZ/SE CA AREA. ALTHOUGH AIRMASS
STILL NOT THAT UNSTABLE OVER THE WESTERN...BUT UNSTABLE OVER THE EAST
PORTION OF CWA. SOME THUNDERSTORMS POSSIBLY SEVERE OVER SOUTHEAST AZ
AND CENTRAL DESERTS UNTIL 03Z TONIGHT. OTHERWISE...SCATTERED
AFTERNOON/ EVENING THUNDERSTORMS SOUTH CENTRAL AZ NEXT FEW DAYS AND
ISOLATED IN WESTERN CWA ESPECIALLY WEDNESDAY/THURSDAY. THUNDERSTORMS
OVER SOUTH CENTRAL AZ WILL BE PROPAGATING WESTWARD INTO THE CENTRAL
DESERTS WITH THE EASTERLY FLOW ALOFT. 12Z PHX SOUNDING REMAINS AN
INVERTED V FOR GUSTY WINDS WITH THE STORMS. MRF EXTENDED KEEP UPPER
HIGH NORTH OF REGION FOR CONTINUED MOIST EASTERLY FLOW FOR LITTLE
CHANGE IN CURRENT PATTERN. UK MODEL HOWEVER SHIFTS HIGH CENTER TO
VICINITY LAS BY WEEKEND WHICH...IF IT OCCURS...WOULD BRING STORMS
DOWN OFF RIM INTO CENTRAL DESERTS RATHER THAN FROM THE EAST.

SEE SEL7 FOR SEVERE THUNDERSTORM WATCH BOX. DKS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 6, 2:00 PM MSTSevere Thunderstorm WarningPSRGila60 min
Jul 6, 3:10 PM MSTSevere Thunderstorm WarningPSRPinal65 min
Jul 6, 3:16 PM MSTSevere Thunderstorm WarningPSRPinal64 min
Jul 6, 4:09 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal91 min

Nearby

Tornado Warnings in Arizona, 1999Every tornado warning in 1999Tornadoes in 1999

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.