Based on the latest advisory from the National Hurricane Center, the earliest reasonable arrival of tropical storm force winds in SC is Thursday afternoon.
Joyce is about 1,040 miles (1,670 km) west-southwest of the Azores, with maximum sustained winds of 40 miles per hour (65 kph), it added.
"Gradual weakening is forecast while Florence moves farther inland during the next couple of days, and it is expected to weaken to a tropical depression" by Saturday night, the center said in a bulletin. The storm surge, major flooding, and damaging winds extending well beyond the center of the storm could cause major damage to coastal communities.
"A life-threatening storm surge is highly likely along portions of the coastline of SC and North Carolina, and a Storm Surge Warning is in effect for a portion of this area", the National Hurricane Center said Wednesday.
As of the 11:00 am Advisory, bands of rain from Isaac will continue to affect the Lesser Antilles.
Tropical Storm Isaac has 45 miles per hour winds and is tracking west. The storm, which just days earlier had been a hurricane, weakened significantly as it approached the the Lesser Antilles and passed with little notice in the USVI, stirring some winds and bringing some hit-or-miss showers to the territory but little else.
"Life-threatening flash flooding is possible with Isaac".
Tropical storm conditions are possible within the tropical storm watch area, also beginning late this morning. Isaac was moving to the west at 21 miles per hour with maximum sustained winds of 45 miles per hour.
For the first time since 2008, there are four named storms in the Atlantic.
The estimated minimum central pressure is 949 mb (28.03 inches).
However, forecasters say Isaac is expected to produce additional rainfall of 2 to 3 inches with isolated maximum totals of up to 5 inches across southeast Puerto Rico.
Tropical Storm Warnings are now in effect for Martinique, Dominica and Guadeloupe.
For tropical storms, two's company, three's a crowd and five is, well, unprecedented.