Isaias, downgraded from a hurricane but still a powerful tropical storm, has gathered strength as it progressed north-northwestward just east of the central coast of Florida, packing strong winds and rain.
The centre of Isaias is expected to move offshore of the coast of Georgia and southern South Carolina on Monday, before continuing inland over eastern North Carolina on Monday evening, the National Hurricane Center (NHC) said.
Tropical Storm Isaias was on Sunday about 105km southeast of Cape Canaveral, Florida heading north-northwestward with top sustained winds of 110km/h, the NHC said in its latest update.
Isaias is expected to move upward along the East Coast and reach Washington, Philadelphia and New York City on Tuesday before moving into New England.
Little change was expected in the storm's strength in the next couple of days, the NHC said.
The Palm Beach area, where President Donald Trump's Mar-a-Lago resort is located, emerged largely unscathed from the storm after it brushed off its coast, with authorities reporting no widespread damage and no flooding.
"We still are experiencing some winds," Lisa DeLaRionda, a spokeswoman for Palm Beach County, said on Sunday.
"However, based on the latest forecast, those winds should be dying down early afternoon."
Although it appeared that Isaias' impact on Florida would not be severe, the storm provided local emergency management with a "real-world scenario" of what extreme weather preparation and response could look like in the midst of a public health emergency as the states battles the coronavirus pandemic, DeLaRionda said.
Tropical storm warnings and watches were in effect for parts of Florida, South and North Carolina, the NHC said.
Australian Associated Press