Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 37, NWS Phoenix, AZ

August 4, 1997Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Aug 4, 1997, 3:25 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 4, 1997, 3:25 PM MST (22:25 UTC)
Expired
Aug 4, 1997, 4:30 PM MST
In force
65 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Pinal County, AZ

The radar

The Phoenix radar (KIWA), 52 km from the middle of the area, began a volume at 22:27 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 12:00Z, 10.4 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 12:00Z on 1997-08-04Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 481 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 12:00Z on 1997-08-04The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
481 J/kg
Mixed-layer CIN
-166 J/kg
Mixed-layer LCL
1666 m above ground
0-6 km bulk shear
16 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
68 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 042226 RRA
SVRPHX
AZC021-042330-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
325 PM MST MON AUG 4 1997

*  SEVERE THUNDERSTORM WARNING FOR
   NORTHWESTERN PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 430 PM MST

*  SOME LOCATIONS AFFECTED
   COOLIDGE
   FLORENCE
   CASA GRANDE
 
*  AT 324 PM MST RADAR INDICATED A LINE OF SEVERE THUNDERSTORMS
APPROACHING THE FLORENCE AND COOLIDGE AREAS. MOVEMENT WAS TO THE
NORTHWEST AT 15 MPH.

STRONG DAMAGING WINDS AND VERY HEAVY RAINFALL ARE LIKELY WITH
THESE STORMS.

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 4, 1:05 PM MST, 2 hours 20 minutes before
AZZ020>025-CAZ030>033-050130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
1 PM MST/PDT MON AUG 4 1997

...THERE IS A MODERATE RISK OF SEVERE THUNDERSTORMS OVER MARICOPA...
NORTHWEST PINAL AND SOUTHERN GILA COUNTIES LATE THIS AFTERNOON AND
THIS EVENING...

A SIGNIFICANT INCREASE IN MOISTURE TOOK PLACE DURING THE WEEKEND
ACROSS CENTRAL AND SOUTHWEST ARIZONA. THIS MOISTURE COMBINED WITH
WARM AFTERNOON TEMPERATURES WILL RESULT IN A VERY UNSTABLE AIR MASS
ACROSS THE OUTLOOK AREA. STRONG AND POSSIBLY SEVERE THUNDERSTORMS
ARE EXPECTED TO DEVELOP THIS AFTERNOON OVER THE HIGHER TERRAIN OF
SOUTHEAST ARIZONA. THESE STORMS WILL GRADUALLY MOVE TOWARD THE
NORTHWEST AND POSSIBLY MOVE INTO PORTIONS OF NORTHWEST PINAL AND
MARICOPA COUNTIES THIS EVENING. THE MAIN THREAT FROM THESE STORMS
WILL BE VERY HEAVY RAINFALL AND SEVERE WINDS. A FEW STORMS MAY
CONTINUE INTO THE NIGHT TIME HOURS WITH HEAVY RAINS BEING THE PRIMARY
THREAT AFTER MIDNIGHT.

SCATTERED THUNDERSTORMS WILL DEVELOP ACROSS SOUTHERN GILA COUNTY
LATER THIS AFTERNOON WITH A FEW STORMS PRODUCING LOCALLY HEAVY
RAINFALL AND POSSIBLY SEVERE WINDS.

ISOLATED THUNDERSTORMS MAY DEVELOP ACROSS EASTERN SECTIONS YUMA AND
LA PAZ COUNTIES. HOWEVER...NO SEVERE WEATHER IS EXPECTED WITH THESE
STORMS.
....................................................................

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                     IN CALIFORNIA

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

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 4, 4:40 PM MSTSevere Thunderstorm WarningPSRGila60 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.