MainThere are several schemes that describe the life-cycle of an average TC. The three schemes shown in Table 6.6 consist of three to four stages. These stages are not really discrete entities, rather they represent a continuous process. Individual stages may even occur more than once during the life-cycle of a particular storm.
4.1 Formation or Genesis Stage
Since the nature of TC development is continuous, features associated with earliest stages of the TC life-cycle can overlap. To complicate the issue, there is no standard language for these initial stages. For example, some meteorologists prefer the term "genesis" to describe both the earliest stages of the life-cycle and progression to a mature hurricane or typhoon. Others use the term "genesis" to describe the earliest stages and "formation" to somewhat later stages in the life-cycle.
4.2 Intensification or Deepening Stage
In this stage, the TC central pressure falls and the maximum surface wind speed increases. An eye may develop at the center of the TC if the stage continues.
4.3 Mature Stage
The mature stage of a TC is usually associated with the period in which the TC reaches maximum intensity. The central pressure has reached a minimum, and the surface winds have reached a maximum.
4.4 Decay Stage
When a TC decays, the central pressure increases and the maximum surface winds weaken. Usually, the decaying process is the result of a TC moving over land, moving over cool water, recurving and assuming extratropical characteristics, or a combination of these processes. Even though the TC is decaying, it can produce high winds and heavy rains.
***** End of SECTION 4 *****
Main
Chapter 6
Section 3
Section 5
Section 4