Hurricane Erin is deemed a potential threat to Bermuda as a Category 4 storm, the Bermuda Weather Service warned. According to the BWS 6am advisory, the storm was upgraded from Category 3 overnight

Additional strengthening is expected as the storm is forecast to “remain a large and dangerous major hurricane through the middle of this week,” the National Hurricane Center said.

Forecasters are watching a new tropical system that may form behind Hurricane Erin, which is intensifying again Monday as it tracks off the U.S. coast.

Hurricane Erin ramped up once again to a category 4 storm early Monday as it blew past Puerto Rico, prompting evacuations in South Carolina’s Outer Banks, and promising to bring deadly rip tides

After weakening a bit, Erin continues to strengthen and grow. A tropical wave could become the next depression or storm.

Hurricane Erin, downgraded to a Category 3 storm, continues to churn and will begin to turn northward in the Atlantic this week, and could bring dangerous surf and rip currents to the Bahamas, Bermuda,

As of Monday morning, Erin is on a steady course to curve around Bermuda and parallel the East Coast. Hurricane Erin weakened from its peak Ccategory 5 status on Saturday due to some structural changes and eyewall replacement cycles in addition to moving away from the best environment for intensification.

Erin is a strong Category 3 hurricane, the National Hurricane Center said in its 8 p.m. ET update Sunday, with sustained winds of 125 mph and tropical storm-force winds reaching out 205 miles. The storm is just over 300 miles northwest of Puerto Rico as of Sunday evening.