A cyclone is an area that is surrounded by a wind system and has a low atmospheric pressure. In the southern hemisphere, the winds blow in a clockwise direction. An area that has a high atmospheric pressure and winds blowing in a counterclockwise direction is known as an anticyclone. In the northern hemisphere, a cyclone's winds blow counterclockwise and an anticyclone's winds blow clockwise.
Subtropical cyclones are very similar to extra tropical and tropical cyclones but unlike most cyclones, subtropical cyclones can occur at any time of year. They are hybrid storms and it is very hard to find consistent characteristics amoung them. The maximum wind intensity they can have is 420 km or 300 mi from the center of the cyclone. Subtropical cyclones have large centers, sometimes as big as 140 km in diameter. In the center there isn't much rain or pressure. They develop from cold-upper-level polar troughs. Sometimes the bottom portion of an upper-level trough cuts off and forms an upper-level-cold-core low. When this reaches the surface, it becomes a subtropical cyclone. They have a very high degree of symmetry and have high levels of persistence. Sub-tropical cyclones don't disappear; instead they hook on to another large storm. Many storms become subtropical cyclones as they decline which brings about many changes such as more rain and increased temperatures. Though subtropical cyclones aren't dangerous by themselves, they need to be watched in case they develop in to something more dangerous, like a tropical cyclone.
A typhoon is a tropical cyclone that has winds of seventy-four miles per hour or more, and forms in the West Pacific Ocean. In order for a typhoon to form, there are several necessary things that must be in place. There must be warm waters, in order to fuel the heat engine of the typhoo; an atmosphere that will cool fast enough with height, so that it is potentially unstable to moist convection; relatively moist layers near the mid-troposphere (3mi); a minimum distance of at least 300 miles (500km) from the equater; a pre-existing near-surface disturbance; and low values (less than about 23mph [10m/s]) of vertical wind shear between the surface and the upper troposphere. Vertical wind sphere is the magnitude of wind change with height. Typhoons begin near the equater and move westward, gathering intensity and size. They advance slowly, usually at about 10 to 15 miles (16-24 km) per hour. But the circular winds around the center are very strong, ofter reaching speeds of 150 miles (240 km) per hour. Typhoon season runs from the first of July through the thirtieth of November. Typhoons are always given names when they are discovered. In the United States, we start back at A every year. In the WesternNorthPacificBasin, they just start where they left off last year.
The first picture is an ariel
view of a cyclone by a satillite, courtesy of www.richard-spiegel.com/.../
The second picture is an ariel view of a typhoon, courtesy of http://www.persidivista.it/sito/card/images/paesaggi/typhoon.jpg As you can see, the two pictures are very similar.