As the eye is known in meteorology that almost windless center of a whirlwind.
The tropical cyclone rotates fast enough, an eye can be formed. The eye is a relatively cloudless, slightly windy area around the center of rotation, in the cold dry air descends from above. An eye can reach up to 320 km in diameter, in exceptional cases, on average, the diameter is less than 50 km. Surrounded is the eye of high -reaching cumulus clouds, the eye wall ( eng.: Eyewall ). The highest wind speeds reached tropical cyclone in the area of this zone.
When the storm has still an additional self-motion, which is added to the rotational speed, the main wind field is always on the side where the self rotation and the movement in the same direction. Example: Blasts a cyclone at a rotational speed of 200 km / h on the northern hemisphere turning it counter clockwise with an airspeed of 30 km / h to the north, so a total velocity results at the eastern eye wall of 230 km / h On the western side, however, only 170 km / h is achieved because the acts proper motion here, contrary to the rotational motion.