Astronaut Ricky Arnold captured this photo of Hurricane Florence from the International Space Station on September 10, 2018. (Credit: NASA) As Hurricane Florence careens toward the Atlantic coast, more than a million Carolina residents are evacuating while millions more are hunkering down with supplies. Hurricane Florence intensified incredibly rapidly this week, morphing from a tropical storm to a Category 4 hurricane in less than 48 hours. How it intensified is understood, but scientists still struggle to predict which Atlantic hurricanes will intensify quickly – or not – during their journey across the ocean.