MIAMI -- Flood watch is in effect for all of South Florida through Saturday evening.

Katrina is forecast to move slowly, which increases the chances for torrential rainfall and storm total amounts of 6 to 12 inches expected through Saturday with localized amounts as high as 15 to 20 inches possible.

If the area gets the anticipated amount of rain, extensive flooding is likely across South Florida similar to that experienced with Hurricane Irene in 1999.

While there is still considerable uncertainty with the path and intensity of Katrina as well as the speed of movement, residents of South Florida are advised to take precautions immediately to prepare for possible flooding.

Flooding could result in travel problems across South Florida beginning as early as Thursday afternoon lasting well into the upcoming weekend.

Residents of flood prone areas should check preparedness requirements and take immediate action to protect property. Checking and cleaning of drainage ditches and ravines can help speed the runoff of excessive rainfall.

A flood watch means conditions are favorable for heavy rains and possible flooding. Persons in the watch area should remain weather alert and be ready for quick action should flooding begin or a warning be issued.