Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 26, NWS Phoenix, AZ

July 29, 1997Maricopa County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 29, 1997, 8:40 PM MST for Maricopa County, Arizona. It was in force for 60 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 29, 1997, 8:40 PM MST (03:40 UTC)
Expired
Jul 29, 1997, 9:40 PM MST
In force
60 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Maricopa County, AZ

The radar

The Phoenix radar (KIWA), 77 km from the middle of the area, began a volume at 03:41 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.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 00:00Z, 3.7 hours before the alert went out and 198 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 1997-07-30Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 804 joules per kilogram.LCLEL10008507005003002001001 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 1997-07-30The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 2 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
804 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
2497 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
2 m²/s²
0-3 km storm-relative helicity
10 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 300341 RRA
SVRPHX
AZC013-300440-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
840 PM MST TUE JUL 29 1997

*  SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN 
   MARICOPA COUNTY IN CENTRAL ARIZONA

*  UNTIL 940 PM MST


*  SOME LOCATIONS AFFECTED ARE....
   GILA BEND AND VICINITY...INCLUDING PORTIONS 
   OF INTERSTATE 8 AND STATE HIGHWAY 85.
 
*  AT 836 PM MST RADAR DETECTED A SEVERE THUNDERSTORM
   8 MILES SOUTHEAST OF GILA BEND.  MOVEMENT WAS TO THE
   NORTHWEST AT 9 MILES PER HOUR.

DAMAGING WINDS IN EXCESS OF 57 MPH AND HAIL GREATER THAN 3/4 INCHES
IN DIAMETER ARE LIKELY WITH THIS STORM. TAKE SHELTER IMMEDIATELY IF
THREATENING WEATHER APPROACHES.D

 
VASQUEZ

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, Jul 29, 2:53 PM MST, 5 hours 47 minutes before
AZZ020>025-CAZ030>033-300130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT TUE JUL 29 1997

...SLIGHT RISK OF SEVERE THUNDERSTORMS THE REST OF THIS AFTERNOON
AND EARLY TONIGHT OVER SOUTHERN GILA COUNTY AND THE TONTO NATIONAL
FORESTS FOOTHILLS...EAST OF THE GREATER PHOENIX AREA...

A SLIGHT RISK OF SEVERE THUNDERSTORMS WILL EXIST OVER THE FAR
EASTERN PORTIONS OF THE OUTLOOK AREA...GENERALLY TO THE EAST OF THE
GREATER PHOENIX AREA...THE REMAINDER OF THIS AFTERNOON AND EVENING.
THE PRIMARY SEVERE WEATHER THREAT WILL BE STRONG...DAMAGING WINDS IN
EXCESS OF 60 MPH. BRIEF...LOCALLY HEAVY RAIN IS ALSO POSSIBLE.

ELSEWHERE WITHIN THE OUTLOOK AREA...ISOLATED EVENING THUNDERSTORMS
ARE POSSIBLE OVER MUCH OF MARICOPA COUNTY...INCLUDING THE GREATER
PHOENIX AREA.  ALTHOUGH THESE THUNDERSTORMS ARE NOT EXPECTED TO
BECOME SEVERE...THEY WILL HAVE THE POTENTIAL FOR WINDS OF OVER 30 MPH
WHICH MAY PRODUCE AREAS OF BLOWING DUST.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIMINISH BEFORE MIDNIGHT.

MEANWHILE...THE FAR SOUTHWEST ARIZONA DESERTS...AS WELL AS THE
EXTREME SOUTHEAST PORTION OF CALIFORNIA ARE EXPECTED TO REMAIN
FREE OF ANY THUNDERSTORMS THROUGH TONIGHT.

ALTHOUGH THE AIR HAS DRIED OUT IN THE MID AND UPPER LEVELS OVER MOST
OF THE OUTLOOK AREA...ENOUGH MOISTURE REMAINS TO GIVE THE ISOLATED
THUNDERSTORM THREAT INTO THE EVENING HOURS.  STRONGER...POSSIBLY
SEVERE THUNDERSTORMS...WILL BE FOUND OVER THE FAR EASTERN OUTLOOK
AREA DUE TO THE PRESENCE OF DEEPER MOISTURE ALONG WITH THE
INTERACTION OF AN UPPER LEVEL DISTURBANCE APPROACHING FROM THE
SOUTH.

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

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                     IN CALIFORNIA

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

CRAIG ELLIS
Special weather statement, Jul 29, 3:04 PM MST, 5 hours 36 minutes before
AZZ020>025-CAZ030>033-300130-

SEVERE WEATHER OUTLOOK...CORRECTION
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT TUE JUL 29 1997

...SLIGHT RISK OF SEVERE THUNDERSTORMS THE REST OF THIS AFTERNOON
AND EARLY TONIGHT OVER SOUTHERN GILA COUNTY AND THE TONTO NATIONAL
FORESTS FOOTHILLS...EAST OF THE GREATER PHOENIX AREA...

A SLIGHT RISK OF SEVERE THUNDERSTORMS WILL EXIST OVER THE FAR
EASTERN PORTIONS OF THE OUTLOOK AREA...GENERALLY TO THE EAST OF THE
GREATER PHOENIX AREA...THE REMAINDER OF THIS AFTERNOON AND THIS
EVENING. THE PRIMARY SEVERE WEATHER THREAT WILL BE STRONG...DAMAGING
WINDS IN EXCESS OF 60 MPH. BRIEF...LOCALLY HEAVY RAIN IS ALSO
POSSIBLE.

MOST SHOWERS AND THUNDERSTORMS ARE EXPECTED TO DIMINISH BEFORE
MIDNIGHT BUT SOME MAY CONTINUE DURING THE NIGHT.

MEANWHILE...THE SOUTHWEST ARIZONA DESERTS...AS WELL AS THE
EXTREME SOUTHEAST PORTION OF CALIFORNIA ARE EXPECTED TO REMAIN
FREE OF ANY THUNDERSTORMS THROUGH TONIGHT.

ALTHOUGH THERE IS LESS MOISTURE IN THE MID AND LOWER LEVELS OF THE
AIRMASS OVER MOST OF THE OUTLOOK AREA...ENOUGH MOISTURE REMAINS TO
GIVE THE ISOLATED THUNDERSTORM THREAT FAR EAST PORTION TONIGHT
MAINLY DURING THE EVENING HOURS. STRONGER...POSSIBLY SEVERE EVENING
THUNDERSTORMS...WILL BE FOUND OVER THE FAR EASTERN OUTLOOK AREA DUE
TO THE PRESENCE OF DEEPER MOISTURE ALONG WITH THE INTERACTION OF AN
UPPER LEVEL DISTURBANCE APPROACHING FROM THE SOUTHEAST.

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

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                     IN CALIFORNIA

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

CRAIG ELLIS

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 29, 9:43 PM MSTSevere Thunderstorm WarningPSRMaricopa62 min
Jul 30, 4:58 PM MSTSevere Thunderstorm WarningPSRLa Paz62 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; radar from the NEXRAD Level II archive.