The awesome fury of this condition can only be experienced. Words are inadequate to describe it. Storms of all sizes result from circular, cyclonic, motion of air around a region of lower air pressure. The largest, called tropical cyclones, occur over the ocean near the equator. On the average some 38 hurricanes form world-wide each year.
Clouds cover most of the storm and underneath are circular bands of very heavy rain.
As air spirals in towards the center, winds increase to as high as 150 mph or more. In the eye air rises to the stratosphere above 40,000 altitude where it is carried off by high altitude winds. The eye, surrounded by a wall of clouds, rain, and wind, is mostly clear of clouds and the wind there is calm. Within the eye atmospheric pressure is 1.5 - 2.0 inches of mercury below normal. The University of Illinois has textbook modules that explain aspects of pressure and storm formation.