Alert archive / California / Flash Flood Warnings in 1997

Flash Flood Warning 14, NWS Phoenix, AZ

September 3, 1997Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Sep 3, 1997, 4:41 PM PDT for Riverside County, California. It was in force for 94 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 3, 1997, 4:41 PM PDT (23:41 UTC)
Expired
Sep 3, 1997, 6:15 PM PDT
In force
94 min
Issued by
NWS Phoenix, AZ
Area
Whole counties

County Riverside County, CA

The radar

The San Diego radar (KNKX), 134 km from the middle of the area, began a volume at 23:42 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 12:00Z, 11.7 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-pSkew-T log-p diagram, San Diego, CA at 12:00Z on 1997-09-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 6 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 12:00Z on 1997-09-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 6 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
6 J/kg
Mixed-layer CIN
-481 J/kg
Mixed-layer LCL
1731 m above ground
0-6 km bulk shear
31 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
65 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KPHX 032342
FFWPHX
CAC065-040115-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
441 PM MST (441 PM PDT) WED SEP 3 1997

*  FLASH FLOOD WARNING FOR
   NORTH CENTRAL RIVERSIDE COUNTY IN SOUTHEASTERN CALIFORNIA

*  UNTIL 615 PM PDT (615 PM MST)

*  SOME LOCATIONS AFFECTED
   JOSHUA TREE NATIONAL MONUMENT
 
*  AT 430 PM MST RADAR ESTIMATED RAINFALLS OF 2 TO 3 INCHES
   HAVE OCCURRED DURING THE PAST HOUR OVER THE SMOKE TREE WASH IN THE
   NORTH-CENTRAL PORTION OF JOSHUA TREE NATIONAL MONUMENT. AS A
   RESULT...FLASH FLOODING IS OCCURRING OR IMMINENT IN THE WARNING
   LOCATIONS.  SMOKE TREE WASH AND OTHER NEARBY WASHES WILL BE
   RUNNING...AND PINTO BASIN ROAD MAY BECOME IMPASSABLE.

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 3, 1:32 PM PDT, 3 hours 9 minutes before
AZZ020>025-CAZ030>033-040130-

SEVERE WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
245 PM MST/PDT WED SEP 3 1997

...A SLIGHT  RISK FOR SEVERE THUNDERSTORMS  OVER SOUTHWESTERN ARIZONA
AND SOUTHEASTERN CALIFORNIA THROUGH THIS EVENING...

THERE  IS A SLIGHT RISK  FOR SEVERE THUNDERSTORMS  THIS AFTERNOON AND
EVENING  FOR  PORTIONS  OF  SOUTHWESTERN  ARIZONA   AND  SOUTHEASTERN
CALIFORNIA.  THIS INCLUDES  THE COUNTIES  OF YUMA...LA  PAZ...WESTERN
MARICOPA...EASTERN RIVERSIDE AND IMPERIAL.  THIS DOES NOT INCLUDE THE
PHOENIX METROPOLITAN AREA.

SCATTERED SHOWERS  AND THUNDERSTORMS WILL DEVELOP  THIS AFTERNOON AND
CONTINUE INTO  THE EVENING HOURS...WITH THE  STRONGEST STORMS LOCATED
WEST  OF THE PHOENIX METROPOLITAN AREA. THE PRIMARY THREAT FROM THESE
STORMS WILL  BE LOCALLY HEAVY RAINFALL  AND FLASH FLOODING...ALTHOUGH
THEY CAN ALSO PRODUCE DAMAGING WINDS AND DEADLY LIGHTNING.

PERSONS IN  SOUTHWEST ARIZONA  AND SOUTHEASTERN CALIFORNIA  SHOULD BE
ALERT FOR DEVELOPING  THUNDERSTORMS. MOTORISTS...ESPECIALLY THOSE  ON
INTERSTATES 8 AND  10...SHOULD BE  ALERT FOR HEAVY  RAIN AND  BLOWING
DUST THAT CAN PRODUCE DANGEROUSLY LOW VISIBILITIES.

SCATTERED THUNDERSTORMS ARE POSSIBLE  THIS AFTERNOON AND EVENING OVER
EASTERN  MARICOPA  COUNTY...INCLUDING  THE  PHOENIX  METRO AREA...AND
SOUTHERN  GILA  COUNTY.  HOWEVER...THESE  STORMS  SHOULD  NOT  BE  AS
STRONG...AND WILL LIKELY  PRODUCE GUSTY WINDS BELOW  50 MPH...AS WELL
AS BRIEF HEAVY RAIN.
.....................................................................

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

BRECKENRIDGE

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 2, 6:25 PM PDTFlash Flood WarningPSRRiverside60 min
Sep 2, 6:25 PM PDTSevere Thunderstorm WarningPSRRiverside60 min
Sep 2, 7:22 PM PDTFlash Flood WarningPSRRiverside58 min
Sep 2, 7:22 PM PDTSevere Thunderstorm WarningPSRRiverside58 min

Nearby

Flash 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.