Flash Flood Watch issued March 20 at 1:45AM PDT until March 23 at 5:00AM PDT by NWS Oxnard
Los Angeles County Coast including Downtown Los Angeles; Los Angeles County Mountains excluding the Santa Monica Range; Los Angeles County San Fernando Valley; Los Angeles County San Gabriel Valley; Santa Clarita Valley; Santa Monica Mountains Recreational Area
...FLASH FLOOD WATCH FOR RECENT BURN AREAS ACROSS SOUTHWESTERN
.A large and powerful storm system across the Eastern Pacific is
expected to approach the West Coast through Friday. A subtropical
fetch of moisture well ahead of the system is expected to bring
periods of moderate to heavy rain to portions of Southwest
California as early as this afternoon and continuing through late
Thursday or early Friday. The most widespread moderate to heavy
rain currently looks to be focused along and ahead of a cold front
pushing through the region Wednesday night into Thursday. Flash
flooding and mud and debris flows are likely in and around recent
burn areas in the watch area. There is the potential that the
Flash Flood Watch will need to be expanded to include areas
outside of recent burn areas during the peak of the storm system
Wednesday night into Thursday. Rain will likely come to an end
behind the cold front sometime late Thursday into early Friday.
Storm total rainfall is expected to range from 2 to 5 inches
across coastal and valley areas, with 5 to locally 10 inches
across the foothills and coastal slopes.
...FLASH FLOOD WATCH REMAINS IN EFFECT FROM WEDNESDAY EVENING
THROUGH LATE THURSDAY NIGHT...
The Flash Flood Watch continues for
* The recent burn areas of Los Angeles county.
* From Wednesday evening through late Thursday night
* Rainfall rates up to 0.6 inches per hour are possible late
Wednesday evening with rates possibly increasing to 0.75
inches per hour or higher at times Thursday.
* Rainfall of this intensity can produce dangerous mud and
debris flows near recent burn areas.
Flash flooding and debris flows will be a particular threat in
and below the recently burned areas.
A flash flood watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.
Southern California residents, in or below the recently burned
areas are urged to take the steps necessary to protect their
property. Persons in the watch area should remain alert and
follow directions of emergency preparedness officials.