Monday 21 February 2005

1:15 p.m. Flood watches and warnings for Southern California coastal areas, mountains and deserts. These alerts and warnings can be expected to also apply to the mountains and deserts of Northern Baja California.

The National Weather Service has issued the following warnings:

FLASH FLOOD WARNING CAZ042-043-048-050-055-056-057-058-060-061-062-220000- FLOOD STATEMENT NATIONAL WEATHER SERVICE SAN DIEGO CA 115 PM PST MON FEB 21 2005 ...FLASH FLOOD WARNING EXTENDED UNTIL 4 PM ALONG AND WEST OF THE MOUNTAINS IN ORANGE...SOUTHWEST SAN BERNARDINO...WESTERN RIVERSIDE...AND SAN DIEGO COUNTIES...AND FOR THE APPLE AND LUCERNE VALLEYS.. ...FLOOD ADVISORY FOR URBAN AND SMALL STREAM FLOODING REMAINS IN EFFECT UNTIL 4 PM FOR THE COACHELLA VALLEY AND THE SAN DIEGO COUNTY DESERTS.. ...FLOOD WATCH FOR FLASH FLOODING FOR ALL OF SOUTHWEST CALIFORNIA UNTIL TUESDAY EVENING.. NATIONAL WEATHER SERVICE DOPPLER RADARS AND SATELLITE IMAGERY SHOWS MODERATE TO HEAVY RAINFALL ALONG AND WEST OF THE MOUNTAINS AND LOCALLY INTO THE APPLE AND LUCERNE VALLEYS. NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS WILL CONTINUE TO MOVE ONSHORE THIS AFTERNOON.

DOPPLER RADAR AND SATELLITE IMAGERY SHOWS A LARGE AREA OF STEADY
RAIN...AND SNOW AT HIGH ELEVATIONS...MOVING SLOWLY OVER THE AREA.
PERIODS OF RAIN...HEAVY AT TIMES WILL CONTINUE OVER
ORANGE...SOUTHWEST SAN BERNARDINO...SAN DIEGO AND WESTERN RIVERSIDE
COUNTIES. RAINFALL RATES OF ONE QUARTER TO ONE HALF INCH PER HOUR
CAN BE EXPECTED...WITH EMBEDDED HEAVIER RATES BRIEFLY APPROACHING
ONE INCH PER HOUR. STRONG SOUTH WINDS OF 20 TO 30 MPH WILL ENHANCE
THE RAINFALL RATES ON THE SOUTH FACING COASTAL SLOPES.

THE GROUND IS SATURATED IN THESE AREAS SO MOST OF THE RAIN THAT IS
FALLING IS RUNNING OFF INTO CREEKS AND STREAMS. MOST FLOODING HAS
BEEN IN THE FORM OF STREET FLOODING OR IN LOW LYING AREAS SUCH AS
FIELDS OR UNDERPASSES. DO NOT CROSS FLOODED AREAS OR GO AROUND
BARRICADES.

SINCE THIS RAINFALL WILL CONTINUE TO POSE A SIGNIFICANT THREAT OF
DANGEROUS AND LIFE THREATENING FLOODING...ESPECIALLY IN AREAS OF
STEEP TERRAIN...A FLOOD WATCH FOR FLASH FLOODING WILL BE IN EFFECT
FOR THE ENTIRE AREA THROUGH TUESDAY AFTERNOON.

THERE IS A SIGNIFICANT THREAT OF MUDSLIDES AND DEBRIS FLOWS OVER
SOUTHWEST CALIFORNIA DURING ANY LONG DURATION MODERATE TO HEAVY RAIN
EVENT...ESPECIALLY IN AND BELOW BURNED AREAS. ALL RESIDENTS LIVING
ON OR NEAR HILLSIDES OR MOUNTAIN SLOPES SHOULD BE PREPARED FOR
POSSIBLE MUDSLIDES AND DEBRIS FLOWS. MUDSLIDES...DEBRIS FLOWS OR
ROCK SLIDES MAY OCCUR AT ANY TIME...EVEN DURING PERIODS WITH LITTLE
OR NO RAIN FALLING.

THE UNITED STATES GEOLOGICAL SURVEY ISSUED A LANDSLIDE AND DEBRIS
FLOW ADVISORY FOR SOUTHERN CALIFORNIA...EFFECTIVE THROUGH MONDAY..
FEBRUARY 21.

$$

FOR FURTHER INFORMATION ON DEBRIS FLOW AND LANDSLIDE HAZARDS...VISIT
THE FOLLOWING USGS WEBSITE..

HTTP://LANDSLIDES.USGS.GOV

STAY TUNED TO NOAA WEATHER RADIO OR WEATHER.GOV/SANDIEGO FOR THE
LATEST WEATHER INFORMATION.

$$

ATKIN/PG