Hurricane Erin regained Category 4 status on Monday morning, packing sustained winds of about 140 mph as it churned roughly 110 miles north of Grand Turk Island. The National Hurricane Center said further strengthening is possible over the next 12 hours while the storm tracks northwest toward the Bahamas before curving between Bermuda and the U.S. East Coast. Although Erin is forecast to remain offshore, its expanding wind field prompted the first tropical-storm and storm-surge watches of the season for North Carolina’s Outer Banks, covering an area from Beaufort Inlet to Duck. Dare and Hyde counties have issued local states of emergency and ordered mandatory evacuations for Hatteras and Ocracoke islands, where tropical-storm-force winds could reach the coast by Wednesday. Forecasters warn that life-threatening surf and rip currents will extend far from the center, with waves of 20 feet or higher expected from Florida to New England later this week. Similar conditions are already affecting the Turks and Caicos, the Bahamas and parts of the Caribbean, where Erin’s outer bands delivered heavy rain. About 6 percent of Puerto Rico remained without power on Monday after weekend flooding. Erin made headlines over the weekend when it leapt from a tropical storm to a 160-mph Category 5 hurricane in only 24 hours—one of the fastest intensification bursts on record for so early in the Atlantic season. The storm is now undergoing an eyewall-replacement cycle that could slightly lower peak winds but enlarge its overall size, broadening coastal hazards despite no expected landfall. The hurricane center is also monitoring a tropical wave emerging from Africa that has a 50–60 percent chance of developing into Tropical Storm Fernand later this week near Puerto Rico, underscoring projections for an above-average Atlantic hurricane season.