devastation. the typhoon is now moving across the south china sea. it's expected to hit central vietnam on sunday. 170,000 troops have been mobilized there. a massive evacuation of over 200,000 people from the coast is now under way. vietnam has already been hammered by two recent typhoons. and of course the typhoon season is well under way. but we've still got two months to go. back to you, kelly. >> david piper, wow, it's just devastating, what's happening over there. >> they're going to need a ton of help. to help us understand what a super typhoon is, our meteorologist is live in the weather center. this is about as extreme as it gets, right? >> this could be historic. this could be the strongest tropical cyclone we have ever seen make landfall. at 190-mile-per-hour sustained winds. an update on what a typhoon is, it's really basically the same thing as a hurricane. we call it a hurricane in the