From the all-caps National Weather Service:

…FLASH FLOOD WATCH NOW IN EFFECT THROUGH SATURDAY AFTERNOON FOR THE RECENT BURN AREAS…

THE FLASH FLOOD WATCH IS NOW IN EFFECT FOR

* THE RECENT BURN AREAS IN VENTURA AND LOS ANGELES COUNTIES.

* THROUGH SATURDAY AFTERNOON

* RAINFALL RATES COULD EXCEED ONE HALF INCH PER HOUR AT TIMES TODAY THROUGH SATURDAY…ESPECIALLY ACROSS SOUTH FACING SLOPES AND NEAR THUNDERSTORMS. THIS WILL BRING THE POTENTIAL FOR FLASH FLOODING AND DEBRIS FLOWS IN AND DOWNSTREAM OF 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 RECENT BURN 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.