Hurricane Dorian took aim at the Bahamas and the Florida coast on Thursday, spurred on by warm Atlantic waters as it threatens to strengthen into a dangerous Category 3 storm.Dorian earlier sideswiped the Caribbean without doing major damage but is expected to strengthen and slam the Bahamas and the southeastern United States with rain, strong winds and life-threatening surf over the next few days, the Miami-based National Hurricane Center said in an advisory.U.S. President Donald Trump urged Floridians to heed official warnings.