1 MITAG will travel W to WSW in the next 48 hours along the southern periphery of the subtropical ridge.

2 WSW is made of analyzer and wrapper, and its design idea and functions are introduced in the paper.

3 The results have indicated that under the actions of WSW winds the contaminants are favored to diffuse seaward, whereas under the actions of E and ESE winds they are accumulated coastward.

4 The direction of the low frequency current with maximum frequency was also WSW.

5 Subject to the anticyclone anchored in central China, 21W will move along its southeastern periphery in a SW to WSW direction in the next 72 hours.