A long-period northerly swell is expected to cause hazardous marine and coastal conditions across the Atlantic waters and passages, and along the northern exposed beaches of the islands beginning Thursday and persisting through the weekend.
The National Weather Service first issued a notice of the high surf and rip currents on Tuesday and on Wednesday added some more specific detail about the times and locations.
According to a release from the Weather Service, seas are forecast to build to around 8 feet or higher for the Atlantic waters, with an 11-second swell that is expected to cause high surf conditions and life-threatening rip currents from the northwest to the east coast of Puerto Rico, Culebra and some beaches of northern Vieques beginning Thursday night.
Across the U.S. Virgin Islands, the main threat is reportedly expected along the west to the northern coast of St. Thomas beginning on Thursday night. The threat of strong rip currents will spread and increase across the rest of the islands on Friday including the north coasts of Saint Croix. High surf may continue through Saturday with breaking waves of 8-10 feet.
The Weather Service reports the following potential hazards:
● Marine: Seas are forecast to build quickly to between 6 and 8 feet, and occasionally up to 10 feet by Thursday afternoon across the offshore Atlantic waters, and between 5 and 7 feet or higher across the Atlantic coastal waters, including the Mona passage. Small Craft Advisory conditions are expected to continue during the weekend as the swell slowly subsides across the offshore Atlantic waters.
● Coastal Areas: The swell is likely to cause large breaking waves between 8 and 12 feet, and occasionally higher at times, along the outer reefs and unprotected beaches with a northern exposure in Puerto Rico, and between 6 and 10 feet, and occasionally higher, in similar areas of Culebra and along the northwestern coast of St. Thomas and the northern coast of Saint Croix. Breaking waves will be associated with life-threatening rip currents and high surf conditions.
The swell is forecast to peak Thursday evening into Friday morning, and then slowly subside through Sunday.