The Hurricane Center said in their early Thursday morning discussion that there are models that forecast Isaias to reach hurricane intensity, but that there is large uncertainty in the future strength of the storm. These conditions are forecast to reach portions of the Dominican Republic and Haiti within the warning area by early Thursday, and the southeastern Bahamas and Turks and Caicos by Thursday afternoon.
Isaias is moving toward the northwest near 20 miles per hour (31 km/h), and a west-northwestward to northwestward motion with some decrease in forward speed is expected during the next couple of days. The effects could be significant, even though Rohrbach said the National Hurricane Center does not forecast Isaias developing into a hurricane.
That's a big "if", however, meteorologists cautioned, saying the storm's ultimate track toward Georgia and the Carolinas was still unknown.
The earliest reasonable time of arrival of tropical-storm-force winds is sometime Sunday night.
Well, folks - Tropical Storm Isaias has formed and SC lies in path as of Thursday morning.
"Potential Tropical Cyclone Nine" had maximum sustained winds of 45 mph and was within 180 miles of Puerto Rico late Wednesday, approaching from the southeast and moving west-northwest at 23 mph, AccuWeather said. If the storm remains strong and largely survives the path over Hispaniola, the storm is likely to strengthen and become a strong tropical storm, staying near or just offshore the Florida east coast this weekend.
A tropical storm watch is in effect for the northwestern Bahamas, including Andros Island, New Providence, Eleuthera, Abacos Islands, Berry Islands, Grand Bahamas Island and Bimini.
"Isaias is expected to move across Hispaniola, as the storm's interaction with the mountainous island should cause some weakening and disruption to the circulation".
The Dominican Republic and the Bahamas could see 4 to 8 inches (10 to 20 centimeters) of rain while Cuba could see 2 to 4 inches (5 to 10 centimeters), with isolated maximum totals of 6 inches (15 centimeters). The islands should expect three to six inches of rain, and up to eight inches in "isolated" areas, the National Weather Service said.
Original story as published Thursday morning below this line.