What are the mechanics of the development of a hurricane?

Question

It'll be best if someone give me the link of a website or an explanation for this question.

Answer 1

A persistent area of rain or thunderstorms forming in the tropical oceans is the first step. When water condenses to form water in the cloud, heat is released into the immediate environment (yes, in the cloud). If this lasts for a while, eventually enough heat is released aloft to create slightly less dense air relative to areas around the storming clouds. Since the air is less dense aloft, this causes lower pressure relative to locations away from the thunderstorm cluster in the air just above the ocean surface. You can think of it this way...if you have a parcel of less dense air aloft relative to parcels to the right or left, then the weight of the air at the surface is less right underneath the less dense air. So this is the beginning of a surface low-pressure.

After the weak surface low-pressure forms, wind begins converging towards the low pressure center. When it converges, it has to go somewhere...up. This keeps the storm cluster going because the updrafts of moist air keep condensing and releasing more heat (called latent heat). This keeps those thunderstorms going, and further enhances the low pressure below. You can see how this creates a feedback-effect making the surface low pressure gradually stronger and stronger.

There are certain things that can disrupt this process, like strong winds aloft. The strong winds aloft tend to pull this heat away from the storms and therefore makes the surface low-pressure formation less effective. During the summer, the atmosphere is usually very calm aloft in tropical ocean regions.

Also, this process is much more efficient when water temps are warmer. When water temps are warmer, the temp of the atmosphere above it tends to match, and warmer air can hold more water vapor. During the initial formation, this very moist air is entrained into the updrafts that I mentioned before. With more moisture, there is more condensation, and more heat release. So the warmer the ocean, the more efficient this formation process is.

(see link below for an image of the ITCZ I'm about to mention)

Finally, there is an area in the tropics called the Inter-tropical Convergence Zone (ITCZ) that migrates well north of the equator during the northern hemisphere summer. Across the earth from north to south there are alternating latitudes of favored wind convergence and the opposite, divergence. The ITCZ is the convergence band in the tropics. Because the wind is convergent at the surface the air must eventually rise, and so there's a huge band of updrafts and persistent showers. This is often the birthplace of hurricanes when this moves far enough north of the equator since the persistent shower/thunderstorm criteria is already a given. But a hurricane can also form off the tail end of a front as it slows down and gradually dissipates in the subtropics (usually how early season hurricanes form close to the U.S., like in June).

Why must it be away from the equator? The hurricane formation process requires at least a little 'Coriolis effect,' and the Coriolis effect is zero at the equator, and generally too small within about 5 degrees north or south of it.

So all these three conditions come together during the summer.

Answer 2

The following are the stages for the development of a hurricane.  First, there is this cold air mass located above an organized cluster of tropical thunderstorms resulting to an unstable atmosphere, creating an environment favorable for the development of a tropical disturbance, the first stage of a developing hurricane. If sustained winds increase to at least

20 to 34 knots, a disturbance is upgraded to a tropical depression.  If speeds still increase to 35 up to 64 knots, the depression is upgraded to a tropical storm.  As surface pressures continue to drop, a tropical storm becomes a hurricane when sustained wind speeds exceed 64 knots.