Alert archive / Arizona / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 22, NWS Phoenix, AZ

July 22, 1997La Paz County, Arizona; Riverside County, California

NWS Phoenix, AZ issued this severe thunderstorm warning at Jul 22, 1997, 8:01 PM MST for La Paz County, Arizona; Riverside County, California. It was in force for 74 min. 2 reports 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 22, 1997, 8:01 PM MST (03:01 UTC)
Expired
Jul 22, 1997, 9:15 PM MST
In force
74 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

Counties La Paz County, AZ, Riverside County, CA

The radar

The Yuma radar (KYUX), 141 km from the middle of the area, began a volume at 03:01 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 22, 8:30 PM MSTThunderstorm Wind 50Blythe, CASpotter reported that thunderstorm winds blew over a large tree which fell on top of his niece's car.
Jul 22, 8:41 PM MSTThunderstorm Wind 50Blythe, CAWinds downed several power poles and large trees. Many street signs were blown down and some roofs sustained damage.

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

San Diego, CA (KNKX), launched 00:00Z, 3.0 hours before the alert went out and 231 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, San Diego, CA at 00:00Z on 1997-07-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 4 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, San Diego, CA at 00:00Z on 1997-07-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
4 J/kg
Mixed-layer CIN
-525 J/kg
Mixed-layer LCL
1453 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
83 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 230305 RRA
SVRPHX
AZC012-CAC065-230415-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
801 PM MST (801 PM PDT) TUE JUL 22 1997

*  SEVERE THUNDERSTORM WARNING FOR:
   WESTERN LA PAZ COUNTY IN WEST CENTRAL ARIZONA
   NORTHEASTERN RIVERSIDE COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 915 PM MST (930 PM PDT)

*  SOME LOCATIONS AFFECTED....
   QUARTZSITE
   POSTON
   COLORADO RIVER
   HIGHWAY 95 FROM 10 MILES NORTH OF BLYTHE TO VIDAL

 
AT 755 PM MST RADAR DETECTED A LINE OF SEVERE
THUNDERSTORMS EXTENDING FROM 32 MILES NORTH
NORTHWEST OF BLYTHE...EXTENDING TO NEAR QUARTZSITE. 
THESE STORMS WERE MOVING NORTHEAST AT 15 MPH.

THESE ARE DANGEROUS STORMS CAPABLE OF PRODUCING STRONG DAMAGING
WINDS IN EXCESS OF 57 MPH...HAIL...AND HEAVY RAIN.   MOBILE HOMES
ARE ESPECIALLY VUNERABLE TO HIGH WINDS.
 
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 22, 2:56 PM MST, 5 hours 5 minutes before
AZZ020>025-CAZ030>033-230130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT TUE JUL 22 1997

...SLIGHT RISK FOR SEVERE THUNDERSTORMS THIS AFTERNOON AND
EVENING OVER PORTIONS OF THE FAR SOUTHEAST CALIFORNIA DESERTS NEAR
IMPERIAL...

SCATTERED THUNDERSTORMS DEVELOPED OVER THE BAJA CALIFORNIA MOUNTAINS
SOUTH OF IMPERIAL AND MEXICALI THIS AFTERNOON.  THESE STORMS WERE
MOVING NORTH TOWARD WESTERN IMPERIAL COUNTY. THERE IS A SLIGHT RISK
OF DAMAGING STRAIGHTLINE WINDS AND LOCALLY HEAVY RAINFALL IN WESTERN
IMPERIAL COUNTY.

THE FAVORED LOCATIONS FOR STRONG THUNDERSTORMS IN WESTERN IMPERIAL
COUNTY ARE FROM THE TOWNS OF HOLTVILLE AND BRAWLEY WESTWARD TO THE
SAN DIEGO COUNTY LINE.  THIS INCLUDES PORTIONS OF INTERSTATE 8 AND
THE SOUTHWESTERN SHORES OF THE SALTON SEA.

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

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                         IN CALIFORNIA

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

VASQUEZ

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 6:16 PM MSTSevere Thunderstorm WarningPSRYuma59 min
Jul 22, 7:02 PM MSTFlash Flood WarningPSRLa Paz78 min
Jul 22, 7:02 PM MSTSevere Thunderstorm WarningPSRLa Paz78 min
Jul 23, 3:44 PM MSTSevere Thunderstorm WarningPSRLa Paz61 min
Jul 22, 6:03 PM MSTSevere Thunderstorm WarningPSRImperial62 min

Nearby

Severe Thunderstorm Warnings in Arizona, 1997Severe Thunderstorm Warnings in California, 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.