Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 8, NWS Phoenix, AZ

July 9, 1997Maricopa County, Pinal County, Arizona

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 9, 1997, 4:15 PM MST for Maricopa County, Pinal County, Arizona. It was in force for 105 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Jul 9, 1997, 4:15 PM MST (23:15 UTC)
Expired
Jul 9, 1997, 6:00 PM MST
In force
105 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

Counties Maricopa County, AZ, Pinal County, AZ

The radar

The Phoenix radar (KIWA), 29 km from the middle of the area, began a volume at 23:17 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.

What was reported inside it

TimeReportWhereRemark
Jul 9, 5:15 PM MSTThunderstorm Wind 51Casa Grande Arpt, AZ

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Tuscon, AZ (KTUS), launched 12:00Z, 11.3 hours before the alert went out and 143 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 1997-07-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 18 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 1997-07-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 11 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
18 J/kg
Mixed-layer CIN
-333 J/kg
Mixed-layer LCL
3368 m above ground
0-6 km bulk shear
9 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
17 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.

903 
WUUS1 KPHX 092316 RRA
SVRPHX
AZC013-021-100100-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
415 PM MST WED JUL 9 1997

*  SEVERE THUNDERSTORM WARNING FOR
   SOUTHERN MARICOPA COUNTY IN CENTRAL ARIZONA
   NORTHWESTERN PINAL COUNTY IN CENTRAL ARIZONA

*  UNTIL 600 PM MST

*  SOME LOCATIONS AFFECTED
   IN MARICOPA COUNTY...MOBILE...BUCKEYE...AVONDALE...AND SUN LAKES
   IN NORTHWEST PINAL COUNTY...CASA GRANDE...STANFIELD...AND
   MARICOPA.
 

*  AT 410 PM MST RADAR INDICATED AN AREA OF STRONG THUNDERSTORMS
   FROM EAST OF GILA BEND TO NEAR CASA GRANDE.  A FEW OF THE STORMS
   WILL LIKELY BECOME SEVERE WITH DAMAGING WINDS AND DENSE
   BLOWING DUST THROUGH 6 PM. STORM MOVEMENT WAS TO THE NORTH AT 20
   MPH.

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 9, 3:07 PM MST, 1 hour 8 minutes before
AZZ020>025-CAZ030>033-100130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
310 PM MST/PDT WED JUL 9 1997

...ISOLATED SEVERE THUNDERSTORMS ARE EXPECTED IN THE OUTLOOK AREA THIS
AFTERNOON AND TONIGHT...

LOWER LEVEL MOISTURE INCREASED THROUGHOUT SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA DURING THE LAST 24 HOURS. ADDITIONALLY...AN UPPER LEVEL SYSTEM
WAS LOCATED WEST OF YUMA...WHICH WILL HELP TRIGGER ISOLATED THUNDERSTORMS
LATE THIS AFTERNOON AND THIS EVENING...FROM ABOUT GILA BEND...TO PHOENIX
AND EASTWARD TO THE GLOBE/MIAMI AREA.

LITTLE OR NO RAINFALL IS EXPECTED...HOWEVER THE MAIN THREAT WILL BE VERY
STRONG AND GUSTY WINDS WITH AREAS OF BLOWING DUST.  MOTORISTS ARE URGED
TO SLOW DOWN AND DRIVE WITH EXTRA CARE THIS EVENING. VISIBILITIES COULD
BE LESS THAN 1/4 MILE AT TIMES AND ISOLATED WIND GUSTS TO NEAR 60 MPH.

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

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
Jul 9, 2:54 PM MSTSevere Thunderstorm WarningPSRMaricopa61 min
Jul 9, 3:55 PM MSTSevere Thunderstorm WarningPSRMaricopa45 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.