Whimsical TV disaster movie Sharknado 2 reeled in 3.9 million viewers, the Syfy specialty channel said Thursday, one day after the sequels broadcast. The followup to last years instant cult classic about a freak weather system that rains a torrent of man-eating sharks on New York City was also a massive hit on social media, at one point dominating the entire top-10 trending list on Twitter, Syfy said. The original Sharknado, set in Los Angeles, drew 1.4 million viewers and prompted 318,000 tweets — key numbers in an era when social media engagement is as important for TV executives as eyeballs glued to the screen.