Typhoon 15W (Tembin)at 12Z 20/August was 420NM SSE of Taipei, Taiwan and was moving NNE at 5 knots.Tembin developed rapidly during the past 24 hours going from at 45 knottropical storm to a currently 110 knot Typhoon.
http://oceanweatherservices.com/blog1/2012/08/20/typhoon-tembin-threatens-taiwan/