Alert archive / Arizona / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 21, NWS Phoenix, AZ

July 14, 1999Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 14, 1999, 5:14 PM MST for Pinal County, Arizona. It was in force for 61 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 14, 1999, 5:14 PM MST (00:14 UTC)
Expired
Jul 14, 1999, 6:15 PM MST
In force
61 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Pinal County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 0.2 hours before the alert went out and 92 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 1999-07-15Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 8 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tuscon, AZ at 00:00Z on 1999-07-15The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 13 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
8 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
2929 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
13 m²/s²
0-3 km storm-relative helicity
12 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 150014 RRA
SVRPHX
AZC021-150115-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
514 PM MST WED JUL 14 1999

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  NORTHWESTERN AND NORTH CENTRAL PINAL COUNTY IN CENTRAL ARIZONA

* UNTIL 615 PM MST

* AT 510 PM MST...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM ABOUT 10 MILES WEST OF CASA GRANDE..r. MOVING
  EAST NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  CASA GRANDE
  COOLIDGE
  FLORENCE

DAMAGING WINDS AND HEAVY RAIN ARE LIKELY. GO INSIDE A STURDY
BUILDING AND STAY AWAY FROM WINDOWS!

CRAIG ELLIS

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 14, 2:45 PM MST, 2 hours 29 minutes earlier.

Area forecast discussion, Jul 14, 2:45 PM MST, 2 hours 29 minutes before
SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST WED JUL 14 1999

.SYNOPSIS...
A MOIST AIRMASS IS MOVING SLOWLY EAST ACROSS SOUTH CENTRAL AZ
TONIGHT. A BROAD TROUGH OF LOW PRESSURE MOVES TO THE EAST TONIGHT
TRIGGERING SCATTERED THUNDERSTORMS WITH HEAVY RAINFALL IN SOUTH
CENTRAL AZ.  A SOUTHWEST FLOW ALOFT ON THURSDAY WILL BRING SLIGHTLY
DRIER AIR INTO THE SOUTHWEST AND SOUTH CENTRAL AREA.  CHANCE OF
AFTERNOON THUNDERTORMS CONTINUES MAINLY TO THE EAST ON FRIDAY AND
INTO THE WEEKEND.

.DISCUSSION...
DEEP CONVECTION OVER SOUTH CENTRAL MIDDAY TODAY HAS TEMPORAIRLY
DIMINISHIED THUNDERTORMS LATE THIS AFTERNOON.  HOWEVER THE STRONG
THUNDERSTORMS SHOULD RETURN THIS EVENING...TRIGGERING ON THE OLD
OUTFLOW BOUNDAIRIES FROM THE PREVIOUS STORMS...A MOVE NORTHEAST
ACROSS THE SAME AREAS THAT HAD RAINS EARLIER TODAY.  THE SUBTLE AXIS
OF A BROAD TROUGH ALOFT SHOULD SWING TO THE EAST OF SOUTH CENTRAL AZ
BY 06Z TONIGHT.  AFTER THE AXIS PASSAGE CNVCTV ACTIVITY SHOULD DMSH.
A WEAK RDIGE FOLLOWS...INTO OUR AREA ON THURSDAY...THEN A E PAC
TROUGH DEEPENS SW OF SRN CA...ON FRIDAY BRINGING A BETTER DEFINED
SOUTHWEST FLOW INTO THE AREA.  THE E PAC TROUGH SHD BE THE DOMINATE
FEATURE THOUGH THE WEEKEND. PERHAPS HEARLDING A SLIGHTLY DRIER CLIME
IN THE SOUTHWEST REGION OF OUR AREA GOING INTO EARLY NEXT WEEK.

IN THE MEANTIME...A FLASH FLOOD WATCH WILL BE IN EFFECT UNTIL 11 PM
MST FOR CENTRAL AZ...MARICOPA...SOUTHERN GILA...AND NORTHWEST PINAL
COUNTY.

Nearby

Severe Thunderstorm Warnings in Arizona, 1999Every severe thunderstorm warning 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.