What began as light rain at the San Diego County coastline overnight spread across the region Wednesday morning — with the heaviest rainfall still to come in the days to follow. Through Friday, between 1.

The National Weather Service reported a 10% to 15% chance of light precipitation on Tuesday as the marine layer deepens from coastal to foothill areas throughout the county.

"Rainfall is expected to decrease to the south with around one-quarter to one-half inch for the Inland Empire and Orange County, and around one-third inch across northern San Diego County to around one-tenth inch across southern San Diego County.