National Weather Service says:
...FLASH FLOOD WATCH REMAINS IN EFFECT THROUGH THIS EVENING...
THE FLASH FLOOD WATCH CONTINUES FOR
* PORTIONS OF CA AND SOUTHWEST CALIFORNIA...INCLUDING THE FOLLOWING AREAS...EASTERN SAN FERNANDO VALLEY...SAN GABRIEL VALLEY...ANTELOPE VALLEY...LOS ANGELES COUNTY MOUNTAINS EXCLUDING THE SANTA MONICA RANGE...AS WELL AS THE STATION...MORRIS...BRIGGS AND CROWN BURN AREAS OF LOS ANGELES COUNTY.
* THROUGH THIS EVENING
* PEAK RAINFALL RATES BETWEEN THREE QUARTERS OF AN INCH AND ONE INCH PER HOUR ARE POSSIBLE. THUNDERSTORMS ARE POSSIBLE TODAY WHICH COULD PRODUCE BRIEF RAINFALL RATES UP TO 2 INCHES PER HOUR.
* FLASH FLOODING WILL BE A THREAT THROUGHOUT CENTRAL AND EASTERN LOS ANGELES COUNTY...WITH DEBRIS FLOWS POSSIBLE IN AND NEAR THE BURN AREAS.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A FLASH FLOOD WATCH MEANS THAT CONDITIONS MAY DEVELOP THAT LEAD TO FLASH FLOODING. FLASH FLOODING IS A VERY DANGEROUS SITUATION.
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 THE DIRECTIONS OF EMERGENCY PREPAREDNESS OFFICIALS.