Erin is the fifth named storm of the Atlantic hurricane season, which runs from June 1 to November 30.
Hurricane Erin, the first hurricane of this year’s Atlantic season, is a Category 3, the United States National Hurricane Center (NHC) said, downgrading the storm from Category 4 as the wind speed eased slightly.
The storm was 330 miles (530km) southeast of Grand Turk Island packing maximum sustained winds of 125 mph (205 kph), the NHC added early on Sunday.
The hurricane had been gauged as high as a catastrophic Category 5 with maximum sustained winds of 160 mph (240 kph), then downgraded to a Category 4. It had earlier been forecast to strengthen into this week.
On Sunday, Erin was moving west-northwest at nearly 14 mph (22 kph) with a decrease in forward speed expected on Sunday and a turn to the north on Monday and Tuesday, the NHC said.
Swells generated by Erin will continue to affect parts of the northern Leeward Islands, the Virgin Islands, Puerto Rico, Hispaniola and the Turks and Caicos Islands for the next couple of days, the NHC said. These swells will spread to the Bahamas, Bermuda, the east coast of the United States, and Atlantic Canada during the early and middle portions of the week.
Rough ocean conditions will likely cause life-threatening surf and rip currents, the NHC added.
The Bahamas, which provides some meteorological services for the Turks and Caicos Islands, has issued a Tropical Storm Watch for the British islands to its southeast.
Erin has also raised concerns about wildfire risks, if human-caused sparks ignite parched vegetation and strong dry winds fan the flames. BMS Group Senior Meteorologist Andrew Siffert said these conditions could arise if Erin grows into a powerful offshore storm prompted by colliding warm and cold air rather than tropical seas.
The US government has deployed more than 200 employees from the Federal Emergency Management Agency and other agencies as a precaution. Puerto Rico Housing Secretary Ciary Perez Pena said 367 shelters were inspected and ready to open if needed.
Officials in the Bahamas are also preparing shelters and urging people to monitor the storm’s progress.
Erin is the fifth named storm of the Atlantic hurricane season, which runs from June 1 to November 30 and is expected to be unusually busy. Six to 10 hurricanes are predicted for the season, including three to five reaching major status with winds of more than 177km/h (110mph).
Scientists have linked rapid intensification of hurricanes in the Atlantic to climate change. Global warming is causing the atmosphere to hold more water vapour and is spiking ocean temperatures, and warmer waters give hurricanes fuel to unleash more rain and strengthen more quickly.
Storms that ramp up so quickly complicate forecasting and make it harder for government agencies to plan for emergencies.