Why TRS recurves?
The recurving of TRS is the result of the rotation of the earth. A cyclone has two components of angular momenta. One is with respect to its own spin axis and the other is with respect to the spin axis of the Earth. When a body with angular momentum, such as a gyroscope, is subjected to a torque it precesses; i.e., it angular momentum vector rotates. If a body with angular momentum is forced to precess then it is subject to a torque. A cyclone rotates with the Earth and its angular momentum vector is kept pointing vertically because of the rising of warm air in its eye (center). The resulting torque forces the cyclone toward the pole in its hemisphere. But as the cyclone moves toward the pole it gets closer to the spin axis of the Earth. The preservation of angular momentum then results in the cyclone moving faster with respect to the pole and hence starts moving east. Its path has thus recurved.