NEW YORK — New York City is banning swimming at its beaches Sunday, and possibly longer, because there may be dangerous riptides as Tropical Storm Hermine spins offshore.

Mayor Bill de Blasio said Friday that bridge closures and other measures could also be ordered as the storm evolves.

He warned New Yorkers to brace for heavy rains, strong winds and flooding in some coastal areas from late Saturday through Wednesday.

The National Hurricane Center is forecasting Hermine could nearly stall out at sea off the mid-Atlantic states Sunday through Wednesday morning.

For now, various New York Labor Day festivals and parades are still on. And Sunday beachgoers can still stroll or sit on the sand, just not swim.

De Blasio calls Hermine “very troubling” and urges New Yorkers to take the storm seriously.