In the view of unusual motion of typhoon Haitang that anticlockwise revolve suddenly when it close to landing at the alongshore in northeast of Taiwan,we used weather map and radar data,analyzed the ambient field and character of typhoon eddy structure,explored the effect of topography of Taiwan Hualian and asymmetric structure of typhoon on the typhoon track.

Analysis of numerical experiment of terrain effects in the course of two kinds of precipitation in SongHua and Lin valley;