Alert archive / Arizona / Flash Flood Warnings in 1997

Flash Flood Warning 1, NWS Phoenix, AZ

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

NWS Phoenix, AZ issued this flash flood warning at Jul 22, 1997, 7:02 PM MST for La Paz County, Arizona; Riverside County, California. It was in force for 78 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 22, 1997, 7:02 PM MST (02:02 UTC)
Expired
Jul 22, 1997, 8:20 PM MST
In force
78 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 02:06 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

San Diego, CA (KNKX), launched 00:00Z, 2.0 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 230204
FFWPHX
AZC012-CAC065-230320-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
702 PM MST (702 PM PDT) TUE JUL 22 1997

*  SEVERE THUNDERSTORM AND FLASH FLOOD WARNING FOR
   WESTERN LA PAZ COUNTY IN WEST CENTRAL ARIZONA
   SOUTHEASTERN RIVERSIDE COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 820 PM MST (820 PM PDT)

*  SOME LOCATIONS AFFECTED
   RIPLEY...BLYTHE AND EHRENBERG
 
*  AT 600 PM MST RADAR DETECTED SEVERE THUNDERSTORMS IN FAR
   SOUTHEAST RIVERSIDE COUNTY APPROACHING RIPLEY...BLYTHE AND
   EHRENBERG FROM THE SOUTHWEST. MOVEMENT WAS TO THE NORTHEAST AT 15
   MPH. THESE STORMS HAVE A HISTORY OF PRODUCING FLASH FLOODING.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. PERSONS
OUT AND ABOUT IN SOUTHEAST RIVERSIDE AND WESTERN LA PAZ COUNTIES
SHOULD USE CAUTION WHILE TRAVELING TONIGHT...AS SOME SECONDARY ROADS
AND LOW-LYING AREAS MAY BE COVERED BY FLOODWATERS.

JAH

What forecasters said that day

The local office's own words before this flash flood 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, 4 hours 6 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 MSTSevere Thunderstorm WarningPSRLa Paz78 min
Jul 22, 8:01 PM MSTSevere Thunderstorm WarningPSRLa Paz74 min
Jul 23, 3:44 PM MSTSevere Thunderstorm WarningPSRLa Paz61 min
Jul 22, 6:03 PM MSTSevere Thunderstorm WarningPSRImperial62 min

Nearby

Flash Flood Warnings in Arizona, 1997Flash Flood Warnings in California, 1997Every flash flood 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.