Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 12, NWS Phoenix, AZ

September 2, 1997Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 2, 1997, 6:25 PM PDT for Riverside County, California. 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: Sep 2, 1997, 6:25 PM PDT (01:25 UTC)
Expired: Sep 2, 1997, 7:25 PM PDT
In force: 60 min
Issued by: NWS Phoenix, AZ
Area: Whole counties

County Riverside County, CA

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 1.4 hours before the alert went out and 154 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 2871 m above ground
0-6 km bulk shear: 28 kt
0-1 km storm-relative helicity: 28 m²/s²
0-3 km storm-relative helicity: 96 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 030126
FFWPHX
CAC065-030225-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM AND FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
625 PM MST (625 PM PDT) TUE SEP 2 1997

*  SEVERE THUNDERSTORM AND FLASH FLOOD WARNING FOR
   CENTRAL RIVERSIDE COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 725 PM PDT (725 PM MST)

*  SOME LOCATIONS AFFECTED...
     DESERT CENTER AND VICINITY ALONG INTERSTATE 10
 
*  AT 623 PDT RADAR DETECTED A SEVERE STORM WITH VERY HEAVY RAIN
   IN THE VICINITY OF DESERT CENTER ALONG INTERSTATE 10.
   THE STORMS WERE NEARLY STATIONARY LENDING TO HIGH FLASH
   FLOOD POTENTIAL.


STRONG DAMAGING WINDS IN EXCESS OF 57 MPH...AND FLOODING ARE
LIKELY WITH THESE STORMS.

VAS"QUEZ

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, Sep 2, 2:45 PM PDT, 3 hours 40 minutes before

AZZ020>025-CAZ030>033-031130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
215 PM MST/PDT TUE SEPT 2 1997

...SLIGHT RISK OF SEVERE THUNDERSTORMS OVER PARTS OF SOUTHWEST
ARIZONA AND FAR SOUTHEAST CALIFORNIA THROUGH THIS EVENING...

THERE IS A  SLIGHT RISK  OF SEVERE THUNDERSTORMS  AGAIN TODAY  ACROSS
PARTS  OF  SOUTHWEST  ARIZONA  AND  FAR  SOUTHEAST  CALIFORNIA.  THIS
INCLUDES THE  ARIZONA COUNTIES OF YUMA...LA  PAZ...AND MAINLY WESTERN
MARICOPA...AND  THE SOUTHEAST  CALIFORNIA  COUNTIES OF  IMPERIAL  AND
EASTERN RIVERSIDE.

SHOWERS  AND THUNDERSTORMS WILL  BE ON THE  UPSWING THE REST  OF THIS
AFTERNOON AND THIS EVENING.  SOME OF THE STRONGER  THUNDERSTORMS THAT
DEVELOP MAY PRODUCE ISOLATED  WINDS IN EXCESS OF  57 MPH AND  LOCALLY
HEAVY DOWNPOURS. MOVEMENT OF THE STORMS  WILL BE TOWARD THE NORTH AND
NORTHWEST AT 15 MPH.

PERSONS IN SOUTHWEST ARIZONA AND  FAR SOUTHEAST CALIFORNIA SHOULD  BE
ALERT FOR  DEVELOPING THUNDERSTORMS.  LOCALLY HEAVY RAIN  AND BLOWING
DUST MAY ACCOMPANY SOME  OF THE STRONGER STORMS...WHICH COULD  BECOME
EXTREME HAZARDS FOR MOTORISTS ON SECTIONS OF INTERSTATES 8 AND 10.
....................................................................

FOR THE PURPOSES OF THIS OUTLOOK...SEVERE WEATHER REFERS TO ANY OF
THE FOLLOWING...DAMAGING WINDS IN EXCESS OF 57 MPH...HAIL 3/4 INCH
IN DIAMETER OR LARGER...AND LOCALLY HEAVY RAINFALL WHICH RESULTS IN
RUNNING WASHES OR FLOODING.

THE OUTLOOK AREA INCLUDES THE FOLLOWING COUNTIES...

IN ARIZONA                              IN CALIFORNIA

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

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 2, 6:25 PM PDT	Severe Thunderstorm Warning	PSR	Riverside	60 min
Sep 2, 7:22 PM PDT	Flash Flood Warning	PSR	Riverside	58 min
Sep 2, 7:22 PM PDT	Severe Thunderstorm Warning	PSR	Riverside	58 min
Sep 3, 4:41 PM PDT	Flash Flood Warning	PSR	Riverside	94 min

Nearby

Flash Flood Warnings in California, 1997 Every 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.