Flash Flood Watch issued March 21 at 3:32AM PDT until March 23 at 5:00AM PDT by NWS SanDiego
Orange County Coastal; Orange County Inland; San Bernardino County Mountains; San Bernardino and Riverside County Valleys-The Inland Empire; Santa Ana Mountains and Foothills
...FLASH FLOOD WATCH IN EFFECT FROM LATE THIS EVENING THROUGH
LATE THURSDAY NIGHT...
.A low pressure system off the California coast will move slowly
towards the coast spreading a strong atmospheric river of
subtropical moisture into portions of central and southern
California. Periods of mostly light rainfall are expected to
continue through this evening. The rainfall is expected to become
heavy at times late tonight and continue into Thursday. Urban and
small stream flooding is likely with flash flooding possible.
Debris flows may also occur near recent burn scars.
...FLASH FLOOD WATCH REMAINS IN EFFECT FROM LATE THIS EVENING
THROUGH LATE THURSDAY NIGHT...
The Flash Flood Watch continues for
* Location...A portion of southwest California...including Orange
County...the San Bernardino County Mountains...and the Inland
* Timing...The heaviest rainfall is expected for late tonight
* Rainfall Rates...Near 0.5 inches per hour with peak short term
rainfall rates of 0.75 inch per hour during periods of the most
* Storm Total Rainfall...Widespread 1.5 to 2 inches near the coast
to 4 to 6 inches along the coastal slopes of the San Bernardino
County mountains with locally greater amounts.
A Flash Flood Watch means that conditions may develop that lead
to flash flooding. Flash flooding is a very dangerous situation.
You should monitor later forecasts and be prepared to take action
should Flash Flood Warnings be issued.