The Category One storm is now on its way to the Bahamas with maximum sustained winds of 130 km/h.
Virginia Governor Ralph Northam has declared a state of emergency ahead of Hurricane Isaias.
"The is risk of impacts from winds, heavy rainfall, and storm surge spreading along much of the US east coast through early next week, and interests there should monitor the progress of Isaias and updates to the forecast", the NHC wrote.
It was forecast to pass over the southeastern Bahamas during the night, be near the central Bahamas late Friday and move near or over the northwestern Bahamas and near South Florida on Saturday.
Some additional strengthening is possible today, and Isaias is forecast to remain a hurricane for the next couple of days.
Hurricane-force winds extend outward up to 35 miles (55 km) from the center of the tropical cyclone and tropical-storm-force winds extend outward up to 175 miles (280 km). The storm is now bringing risky rains to the Bahamas. "Hurricane conditions are expected to begin in the southeastern Bahamas this morning and spread into the central and northwestern Bahamas tonight and into Saturday", it added.
A Hurricane Watch is in effect from Hallendale Beach to south of Boca Raton, Florida.
Isaias was expected to drop from 4 to 8 inches (10 to 20 centimeters) of rain in the Bahamas and the Turks and Caicos Islands. The system is moving northwest at 28 km/h and a northwestward motion with some drop in speed is expected over the next couple of days followed by a shift to the north-northwest.
Flooding may be similar to what the county experienced with Hurricane Dorian, he said, and may begin as early as Sunday's first high tide, at 1 a.m., or, more likely, the second high tide at around 1 p.m. "This rain could result in isolated flash and urban flooding, especially in low-lying and poorly drained areas, as well as isolated minor river flooding".
"Our sites, because they're outdoors with tents, if it were to get 40-, 50-mile-per-hour winds, it would just collapse", he said.
Safety concerns about the storm prompted the Florida Division of Emergency Management to close all state-supported COVID-19 testing sites for several days, starting Thursday evening. People who are infected with the new coronavirus and need to evacuate will be isolated in classrooms separate them from the general population, Gimenez said.
Because of COVID-19, the shelter will require entry screenings, daily temperature screenings, social distancing and face coverings. If the track moves farther east and out to sea, then our impacts will be far less.