A typhoon is a mature tropical cyclone that develops in the northwestern part of the Pacific Ocean in a region referred to as the northwest Pacific basin. They are identical in all ways to hurricanes, apart from location and name, and hurricanes whose paths take them into the Pacific ocean get re-assigned the typhoon tag.
The names of typhoons are discussed between 18 countries, all of whom have territories endangered by the phenomena. In the Philippines however, their is a different naming system for typhoon systems that approach the country.
There are six main requirements for a typhoon to form: Sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low pressure center, a pre-existing low level focus or disturbance, and low vertical wind shear. These conditions are necessary for tropical cyclones to form, but the existence of all of them still does not guarantee one will form.
Whether it's a depression in the intertropical covergence zone or monsoon trough, a broad surface front, or an outflow boundary, a low level feature with sufficient vorticity and convergence is required to start a tropical storm, and about 85 to 90 percent of Pacific typhoons form within the monsoon trough. Even if there is a perfect upper level conditions and the required atmospheric instability, a lack of a surface focus will prevent the development of organized convection and surface low. Poor vertical wind shear between the ocean surface and the tropopause is required for tropical cyclone development, and typically with Pacific typhoons, there are two outflow jets: One to the north ahead of an upper trough in the Westerlies, and a second towards the equator.
The names of typhoons are discussed between 18 countries, all of whom have territories endangered by the phenomena. In the Philippines however, their is a different naming system for typhoon systems that approach the country.
There are six main requirements for a typhoon to form: Sufficiently warm sea surface temperatures, atmospheric instability, high humidity in the lower to middle levels of the troposphere, enough Coriolis force to develop a low pressure center, a pre-existing low level focus or disturbance, and low vertical wind shear. These conditions are necessary for tropical cyclones to form, but the existence of all of them still does not guarantee one will form.
Whether it's a depression in the intertropical covergence zone or monsoon trough, a broad surface front, or an outflow boundary, a low level feature with sufficient vorticity and convergence is required to start a tropical storm, and about 85 to 90 percent of Pacific typhoons form within the monsoon trough. Even if there is a perfect upper level conditions and the required atmospheric instability, a lack of a surface focus will prevent the development of organized convection and surface low. Poor vertical wind shear between the ocean surface and the tropopause is required for tropical cyclone development, and typically with Pacific typhoons, there are two outflow jets: One to the north ahead of an upper trough in the Westerlies, and a second towards the equator.
