Between 1 and 1.5 inches of rain were expected to come down Sunday, and up to four total for the weekend.
Flooding was the main concern with a marginal risk of severe thunderstorms possible in the evening, the National Weather Service said.
The flood watch will be in effect until 10 p.m. After that, rain was expected to taper off and stop sometime between midnight and daybreak.
"The primary hazard is expected to be damaging straight line winds. The risk is primarily across Delmarva, South Jersey, and extreme southeastern PA," the NWS said.
Tidal flooding was also a risk along back bays in Ocean County.
"While tidal flooding is expected to stay minor, this could exacerbate issues with freshwater flooding in these areas," the NWS said, noting a coastal flood advisory was in effect.
Monday will be sunny with a high around 60.
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