"Swells generated by Chris are expected to increase and affect portions of the coasts of North Carolina and the mid-Atlantic states into early next week", the NHC said, adding that some of the resulting conditions could be life-threatening.
Walsh says the potential for flooding on the south coast depends on when the storm passes and whether it coincides with high tide.
Tropical-storm-force winds extend outward up to 60 miles from the center.
As Beryl approached, Puerto Rico, a US territory, was still recovering from the devastation of Maria, which struck the island on September 20, 2017, as Category 4 hurricane with maximum wind speeds of 155 miles per hour.
Although Beryl has lost strength and is expected to gradually weaken, forecasters said it will produce strong winds and heavy rainfall across the Leeward Islands, the Virgin Islands, Puerto Rico and Hispaniola through Tuesday. More than 1,500 power customers remain in the dark more than nine months after Maria, and some 60,000 people still have only tarps for roofs.More news: England sink Sweden to clinch World Cup semi-final berth
The DDM said a high wind advisory is in effect.
The National Hurricane Center in Miami said Sunday that the storm has barely moved since Saturday.
High surf and risky rip currents are expected along parts of the Carolina and mid-Atlantic coasts through early week.
No coastal watches or warnings are effect because of Chris. It has been a mostly stationary storm so far, sustaining maximum wind speeds close to 45 miles per hour, but is expected to remain "well offshore" of the USA coast.
A tropical storm warning is up on Guadeloupe and Dominica, while a tropical storm watch has been issued for the French Caribbean territories of Martinique, St. Martin and St. Barts as well as St. Maarten, Barbados, St. Lucia, Saba and St. Eustatius.