With the projected forecast taking the core of Elsa and/or its leftovers near the Shore’s barrier islands, the National Hurricane Center has hoisted a tropical storm warning for for the entire New Jersey and Delaware coasts, warning of winds up to 39 mph or higher.

And given the subtle westward shifts this week in the projected path, and the possibility that Elsa will mutate into a more widespread rainstorm, the National Weather Service Office in Mount Holly has issued a flash flood watch for the entire region with the potential for isolated amounts of up to five inches.

The clearest rain threat would be from I-95 eastward, said Nicholas Carr, a lead meteorologist at the Mount Holly Office, but “it wouldn’t take much of a shift” for downpours to spread farther inland, thus, the expansion of the watch west of the city.

» READ MORE: Heavy rains cause flooding at Shore and in Philly as Tropical Storm Fay deluges the region

At the Shore, heavy rain is a near certainty, the weather service said, with “moderate flooding” in play, leading to street flooding and perhaps even prompting some water rescues. Tornadoes, which frequently accompany tropical systems, also are possible.

Tracking Elsa

After making landfall in northern Florida, by Thursday morning Elsa, downgraded to a “depression,” had crossed into the Carolinas, its peak winds reduced to 35 mph, the hurricane center said.

It was forecast to arc northeastward, cross Delmarva, and approach Cape May early Friday, having regained tropical storm strength.

Once it gets here

As it travels north, Elsa could lose its tropical characteristics and become more of a mid-latitude rainstorm, said Carr. Practically, that would mean the heavier rains would extend farther from the center.

» READ MORE: Isaias leaves destruction and thousands in Philly region without powe

Also, it could gain some strength from interacting with the upper air up this way.

Rains are expected to begin across the region around sunset Thursday, about the same time that winds are due to pick up at the Shore, and continue heavily at times into Friday morning.

The flood watch is in effect until noon Friday. In fact, the National Centers for Environmental Prediction has most of the East Coast from North Carolina to Maine at risk for “excessive rainfall.”

More showers are possible later Friday as a front approaches, Carr said.

Saturday should be a thing of beauty with sun and highs in the mid-80s. But then shower chances appear in the forecasts Sunday, Monday, and Tuesday.

At least the extreme heat is over for a while. On Wednesday, the heat index made it to triple digits for a second straight day. No 90-degree highs are in the forecast well into next week.