Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 80, NWS Phoenix, AZ

August 30, 1997Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 30, 1997, 7:25 PM MST for Pinal County, Arizona. It was in force for 65 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
Aug 30, 1997, 7:25 PM MST (02:25 UTC)
Expired
Aug 30, 1997, 8:30 PM MST
In force
65 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Pinal County, AZ

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 2.4 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 1997-08-31Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 565 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 1997-08-31The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 17 square meters per square second.193958Sfc1 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
565 J/kg
Mixed-layer CIN
-33 J/kg
Mixed-layer LCL
2339 m above ground
0-6 km bulk shear
11 kt
0-1 km storm-relative helicity
17 m²/s²
0-3 km storm-relative helicity
18 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 310225 RRA
SVRPHX
AZC021-310330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
725 PM MST SAT AUG 30 1997

*  SEVERE THUNDERSTORM WARNING FOR
   NORTHWESTERN PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 830 PM MST

*  SOME LOCATIONS AFFECTED
   SACATON
   BLACKWATER
   COTTONWOOD
 
*  AT 725 PM MST RADAR INDICATED A SEVERE THUNDERSTORM 10 MILES
   NORTHWEST OF COOLIDGE. MOVEMENT WAS TO THE NORTHEAST AT 5 MPH.

STRONG DAMAGING WINDS ARE LIKELY WITH THIS STORM. OTHER STRONG STORMS
WILL AFFECT PORTIONS OF NORTHWEST PINAL COUNTY.

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.

In the hours before

Special weather statement, Aug 30, 3:18 PM MST, 4 hours 7 minutes before
AZZ020>025-CAZ030>033-311130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT SAT AUG 30 1997

...A FLASH FLOOD WATCH IS IN EFFECT FOR MUCH OF ARIZONA UNTIL 9 PM
MST...

...MODERATE RISK OF SEVERE THUNDERSTORMS OVER MARICOPA AND NORTHWEST
PINAL COUNTIES THIS AFTERNOON AND TONIGHT...

...SLIGHT RISK OF SEVERE THUNDERSTORMS OVER LA PAZ...SOUTHERN
GILA...AND FAR NORTHERN YUMA COUNTIES THIS AFTERNOON AND TONIGHT...

OUTFLOWS FROM THUNDERSTORMS OVER NORTHWEST AND SOUTHEAST ARIZONA ARE
ANTICIPATED TO MOVE INTO MARICOPA AND NORTHWEST PINAL COUNTIES THIS
EVENING...AND GENERATE THUNDERSTORMS WHICH COULD PRODUCE VERY HEAVY
RAINFALL IN EXCESS OF 1 INCH PER HOUR...WHICH COULD LEAD TO FLOODING
OF STREETS AND WASHES..AND DAMAGING WINDS.  IF ANY SEVERE STORMS
FORM...THEY WILL MOST LIKELY OCCUR BETWEEN 5 PM AND 10 PM.

THE PRIMARY THREAT FROM THUNDERSTORMS OVER LA PAZ...SOUTHERN
GILA...AND FAR NORTHERN YUMA COUNTIES WILL BE HEAVY RAIN IN EXCESS
OF 1 INCH PER HOUR WHICH COULD LEAD TO FLOODING OF STREETS OR
WASHES. THE STORMS WILL LIKELY PRODUCE WINDS GUSTS TO NEAR 50
MPH...ALSO. THE THREAT OF SEVERE WEATHER IN THESE COUNTIES ARE
EXPECTED TO END BY 9 PM.

THE AIR MASS OVER THE SOUTHWEST U.S.  HAS BECOME QUITE MOIST AND
UNSTABLE ...THUS THERE IS A THREAT OF THUNDERSTORMS FORMING ANYWHERE
IN THE OUTLOOK AREA.  HOWEVER...OUTSIDE THE AREAS WHERE THERE IS A
RISK OF SEVERE THUNDERSTORMS...ONLY ISOLATED THUNDERSTORMS WITH
STRONG WINDS TO NEAR 50 MPH...DENSE BLOWING DUST OR SAND...AND BRIEF
HEAVY RAIN ARE EXPECTED.

....................................................................

FOR PURPOSES OF THIS OUTLOOK...SEVERE WEATHER REFERS TO ANY OF THE
FOLLOWING...DAMAGING WINDS IN EXCESS OF 57 MPH...HAIL 3/4 INCH IN
DIAMETER OR LARGER...AND LOCALLY HEAVY RAINFALL WHICH RESULTS IN
RUNNING WASHES OR FLOODING.

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA IN CALIFORNIA

MARICOPA IMPERIAL
SOUTHERN GILA CENTRAL/EASTERN RIVERSIDE
NORTHWEST PINAL
YUMA
LA PAZ
....................................................................

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 30, 5:26 PM MSTSevere Thunderstorm WarningPSRMaricopa44 min
Aug 30, 6:14 PM MSTSevere Thunderstorm WarningPSRMaricopa, Pinal46 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1997Every severe thunderstorm warning in 1997

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.