Tidal flooding is likely and forecasters say the chance for snow is becoming more certain as a strong coastal storm is expected to begin affecting the region by early Wednesday.

A winter storm watch is now in effect for all of South Jersey, including the coastal areas, for between 3 and 5 inches of snow. The National Weather Service also has issued a coastal flood warning for today  and early Thursday, warning widespread moderate level flooding is expected, with the potential for major level flooding in places.

The weather service also has issued a high wind warning for the barrier islands and Cape May County and a wind advisory for the rest of South Jersey.

Forecasts call for the water level at the Atlantic City tidal gauge to near 7.8 feet during the high tide early Thursday. Forecasts also call for minor to moderate flooding levels during high tide along the oceanfront until early Saturday. That could mean that floodwaters could get bottled up in the back bays, said Gary Szatkowski, meteorologist in charge at the National Weather Service, Mt. Holly.

Moderate tidal flooding in Atlantic City occurs when the water level reaches 7 feet above the average lowest tide mark. When the water reaches that level, many flood-prone roads will be underwater and property damage is possible. When the water level reaches 8 feet in Atlantic City, more widespread damage is possible.

By comparison, the water level during Hurricane Sandy reached 8.8 feet on the oceanfront in Atlantic City, but up to 10.5 feet in the bays.

Ocean City already has warned residents that if they are in flood-prone areas, that they should move their cars to higher ground before this  evening. Northern Ocean County towns still struggling with storm-damaged infrastructure, including coastal sections of Brick and Toms River, have issued voluntary evacuations.

“This will be another ‘new normal’ experience, where places that normally have not seen flooding with moderate levels will see it this time around,” Szatkowski said. “If you flooded in moderate coastal flooding post Sandy, it’s going to happen again.”

Whether or not the region will see snow from the storm will depend on how cold temperatures get, said Larry Nierenberg, NWS meteorologist. “If this was January, it would be all snow everywhere. But it’s March now so during daylight hours will be mix of rain and snow or just plain rain,” he said.

The heaviest precipitation is expected to fall in the evening and overnight hours, when temperatures are cooler. Between 1 inch and 1.75 inches of rain is expected to fall across South Jersey starting about midnight Wednesday, Szatkowski said. “If half of that falls as snow, that’s a lot of snow.”