The storm is 170 kilometres north of Anguilla, with maximum sustained winds near 255 km/h.
While the hurricane's eye isn't expected to hit land, it threatens to dump flooding rains as it continues to grow larger.
The centre said on Friday that Erin is expected to strengthen over the southwestern Atlantic through the weekend and into next week.
Swells generated by Erin will affect portions of the northern Leeward Islands, the Virgin Islands, Puerto Rico, Hispaniola, and the Turks and Caicos Islands through the weekend.
The Bahamas, Bermuda and the east coast of the United States will be affected early next week, it said.
Erin has also raised concerns about another unforeseen risk - wildfires.
Andrew Siffert, a senior meteorologist at BMS Group, noted that if Erin evolves into a large, intense extratropical cyclone offshore, a dangerous alignment could occur - critically dry fuels across the region and strong and dry winds driven by Erin's pressure gradient.
ILS investment manager Twelve Securis said on Friday that Erin is forecast to remain far enough offshore to spare the US east coast from significant impacts.
The storm is projected to pass north of the northern Caribbean Leeward Islands before turning north between the US east coast and Bermuda around Monday.
Erin is expected to produce areas of heavy rainfall through Sunday across the northern Leeward Islands, the Virgin Islands and Puerto Rico.
with AP
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