"Tomorrow will be dryer than today, but it will be a long day today," said Blake, acting branch chief of the NHC's hurricane specialist unit, referring to Puerto Rico. "The strongest winds are already dying down and it's already over the Dominican Republic."
Puerto Rico's power grid remains fragile despite emergency repairs after Hurricane Maria in September 2017 caused the largest blackout in U.S. history, according to the Puerto Rican think tank Center for a New Economy.
In that Category 5 storm, which killed more than 3,000 people, 1.5 million customers lost electricity with 80% of power lines knocked out. Thousands of Puerto Ricans still live under makeshift tarpaulin roofs.