Alert archive / California / Flash Flood Warnings in 2003

Flash Flood Warning 16, NWS Phoenix, AZ

August 27, 2003Riverside County, California

NWS Phoenix, AZ issued this flash flood warning at Aug 27, 2003, 8:00 PM PDT for Riverside County, California. It was in force for 30 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 27, 2003, 8:00 PM PDT (03:00 UTC)
Expired
Aug 27, 2003, 8:30 PM PDT
In force
30 min
Issued by
NWS Phoenix, AZ
Area
Counties, with a storm outline in the text

County Riverside County, CA

The radar

The Santa Ana Mts radar (KSOX), 135 km from the middle of the area, began a volume at 03:15 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this flash flood warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

San Diego, CA (KNKX), launched 00:00Z, 3.0 hours before the alert went out and 159 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 2003-08-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 2003-08-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -7 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1973 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
-7 m²/s²
0-3 km storm-relative helicity
8 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 
WGUS55 KPSR 280304
FFWPSR
CAC065-280330-

BULLETIN - EAS ACTIVATION REQUESTED
FLASH FLOOD WARNING
NATIONAL WEATHER SERVICE PHOENIX AZ
800 PM PDT WED AUG 27 2003

THE NATIONAL WEATHER SERVICE IN PHOENIX HAS ISSUED A

* FLASH FLOOD WARNING FOR JOSHUA TREE NATIONAL PARK...
  NORTH CENTRAL RIVERSIDE COUNTY IN SOUTHEAST CALIFORNIA

* UNTIL 830 PM PDT

* AT 754 PM PDT...WEATHER SERVICE DOPPLER RADAR INDICATED VERY 
  HEAVY RAIN 3 MILES SOUTHEAST OF YUCCA VALLEY...MOVING SOUTH
  AT 10 MPH.

THUNDERSTORMS WITH VERY HEAVY RAIN WERE BETWEEN THE WEST ENTRANCE
OF JOSHUA TREE AND BLACK ROCK CANYON...IN THE NORTHWEST PART
OF THE PARK.

EXCESSIVE RUNOFF FROM THIS STORM WILL CAUSE FLASH FLOODING OF CREEKS
AND STREAMS...ROADS AND ROADSIDE CULVERTS. THE HEAVY RAINS COULD ALSO
TRIGGER ROCK AND MUDSLIDES IN STEEP TERRAIN.

BE ESPECIALLY CAUTIOUS AT NIGHT WHEN IT IS HARDER TO RECOGNIZE THE
DANGERS OF FLOODS AND FLASH FLOODS. IF FLASH FLOODING IS OBSERVED ACT
QUICKLY. MOVE UP TO HIGHER GROUND TO ESCAPE FLOOD WATERS. DO NOT STAY
IN AREAS SUBJECT TO FLOODING WHEN WATER BEGINS RISING.

A FLASH FLOOD WARNING MEANS THAT FLOODING IS IMMINENT OR OCCURRING.
IF YOU ARE IN THE WARNING AREA MOVE TO HIGHER GROUND IMMEDIATELY.
RESIDENTS LIVING ALONG STREAMS AND CREEKS SHOULD TAKE IMMEDIATE
PRECAUTIONS TO PROTECT LIFE AND PROPERTY. DO NOT ATTEMPT TO CROSS
SWIFTLY FLOWING WATERS OR WATERS OF UNKNOWN DEPTH BY FOOT OR BY
AUTOMOBILE. IF YOUR VEHICLE STALLS...ABANDON IT IMMEDIATELY AND SEEK
HIGHER GROUND.

TO REPORT SEVERE WEATHER HAVE THE NEAREST LAW ENFORCEMENT AGENCY
RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST OFFICE IN
PHOENIX.

LAT...LON 3401 11637 3378 11630 3389 11586 3401 11601
          3401 11617

$$

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.

NWS Phoenix, AZ wrote its last area forecast discussion before this flash flood warning went out at Aug 27, 3:15 PM PDT, 4 hours 45 minutes earlier.

Area forecast discussion, Aug 27, 3:15 PM PDT, 4 hours 45 minutes before
AZZ020>028-CAZ030>033-280545-

SOUTHWEST ARIZONA/SOUTHEAST CALIFORNIA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PHOENIX AZ
315 PM MST WED AUG 27 2003

.SYNOPSIS...
ABUNDANT MOISTURE FROM FORMER HURRICANE IGNACIO WILL CONTINUE OVER
THE AREA THROUGH THIS EVENING. THIS MEANS SCATTERED SHOWERS AND
THUNDERSTORMS...SOME WITH HEAVY RAIN THROUGH THIS EVENING...
FOLLOWED BY A DECREASING CHANCE LATE TONIGHT. HIGH PRESSURE ALOFT
FROM THE PACIFIC IS EXPECTED TO BRING WARMER WEATHER AND SOME
REDUCTION IN SHOWERS AND THUNDERSTORMS THURSDAY...WITH A FURTHER
REDUCTION AND SOME ADDITIONAL WARMING FRIDAY...THEN LITTLE CHANGE IS
ANTICIPATED THROUGH THE LABOR DAY WEEKEND AND MIDDLE OF NEXT WEEK.

.DISCUSSION...
A FLASH FLOOD WATCH CONTINUES IN EFFECT FOR SOUTH-CENTRAL AND
SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA TODAY THROUGH 11 PM
MST/PDT OR 0600 GMT TONIGHT. ABUNDANT MOISTURE FROM FORMER HURRICANE
IGNACIO CONTINUES OVER THE AREA. THE AIRMASS HAS HAD ABOUT AS MUCH
MOISTURE AS IT EVER DOES IN SOUTHEAST CALIFORNIA...SOUTHWEST AND
SOUTH-CENTRAL ARIZONA. THIS LENDS SUPPORT TO CONTINUE THE FLASH
FLOOD WATCH THROUGH THIS EVENING. HIGH PRESSURE ALOFT WITH DRIER AIR
FROM THE PACIFIC IS EXPECTED TO GRADUALLY MOVE EAST WITH A
DECREASING CHANCE OF SHOWERS AND THUNDERSTORMS LATE TONIGHT...THEN
WARMER WEATHER AND LESS THUNDERSTORMS ARE EXPECTED THURSDAY COMPARED
WITH TODAY. AS THE AIRMASS CONTINUES TO BECOME DRIER...SOME FURTHER
WARMING AND EVEN LESS CHANCE OF SHOWERS AND THUNDERSTORMS IS FORECAST
FOR FRIDAY...THEN LITTLE CHANGE THROUGH THE LABOR DAY WEEKEND AND
THE MIDDLE OF NEXT WEEK. IN FACT...HAVE TAKEN OUT THE MENTION OF
SHOWERS AND THUNDERSTORMS IN SOUTHEAST CALIFORNIA BEGINNING FRIDAY.

.PSR...FLASH FLOOD WATCH FOR THE ENTIRE AREA...SOUTH-CENTRAL AND
       SOUTHWEST ARIZONA ZONES 20 THROUGH 28...AND SOUTHEAST
       CALIFORNIA ZONES 30 THROUGH 32 TODAY THROUGH 11 PM MST/PDT
       TONIGHT OR 28/0600 GMT.

ELLIS
Hazardous weather outlook, Aug 27, 9:39 AM PDT, 10 hours 21 minutes before
AZZ020>028-CAZ030>033-280100-

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PHOENIX AZ
939 AM MST WED AUG 27 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHWEST AND
SOUTH-CENTRAL ARIZONA...AND SOUTHEAST CALIFORNIA.

.DAY ONE...TODAY

...FLASH FLOOD WATCH FOR SOUTH-CENTRAL AND SOUTHWEST ARIZONA...
AND SOUTHEAST CALIFORNIA TODAY THROUGH 11 PM TONIGHT...

SHOWERS AND THUNDERSTORMS ARE FORECAST TO PRODUCE SOME HEAVY RAIN
WITH EXCESSIVE VERY HEAVY RAIN AND FLASH FLOODING IN SOME AREAS.
THIS SITUATION WILL BE ENHANCED WHERE THE GROUND IS ALREADY
SATURATED...AND ANY ADDITIONAL RAINFALL WILL LEAD TO RAPID RUNOFF.
AVOID LOW SPOTS...HIGHWAY DIPS...WASHES AND CREEKS THAT COULD EASILY
BECOME FLOODED. STAY AWAY FROM FLOODED ROADS AND OTHER FLOOD PRONE
AREAS. IF YOU OBSERVE FLOODING...DO NOT WAIT FOR A WARNING TO BE
ISSUED...MOVE TO HIGHER GROUND IMMEDIATELY.

.DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY

THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW.

.INSTRUCTIONS TO SKYWARN SPOTTERS...
SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS
ACCORDING TO STANDARD OPERATING PROCEDURES.

ELLIS

In the hours before

Local storm report, Aug 27, 2:10 PM PDT, 5 hours 50 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PHOENIX, AZ
210 PM MST WED AUG 27 2003

TIME(MST)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0745 PM    10 NW GLOBE               AZ   FLASH FLOODS
08/26/03   GILA                           BRIEF ROAD CLOSURES
                                          REPORTED ON SR-88. ONE
                                          VEHICLE STUCK IN WASH HAD
                                          TO BE RESCUED. REPORTED BY
                                          LAW ENFORCEMENT

FOWLE

Nearby

Flash Flood Warnings in California, 2003Every flash flood warning in 2003

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.