A Cyclone is a large area of low pressure which is in either an elliptical orbit around the earth or rotating rapidly about its axis. In meteorology, a cyclone can be a large scale atmospheric mass which rotates round a highly persistent center of low horizontal pressure, clockwise in the Northern Hemisphere (northeastern US), counter clock wise in the Southern Hemisphere (southeastern US), and inward-wards in some cases. Cyclones are generally characterized by inwards spiraling winds which rotate around a highly persistent low pressure area. These winds usually move at high velocities, speeds which would produce a visible “eye” on the skies in a major storm. A “low pressure area” on the Earth is generally an area which can support a surface wind of some form, and can therefore act as a vortex or hub of winds within an atmosphere.
Hurricane or typhoon storms often generate enormous rainfall amounts which can surpass record breaking totals during a single occurrence. Cyclones do not have a single nucleus; they form many different mini vortexes which may converge in a larger body. When a storm reaches a significant level of intensity (storm cells form into cells in a thunder storm), the speed of these cells becomes so great that it creates a rapid downdraft that literally sucks the air into the core of the storm. This intensifying effect causes massive amounts of rainfall to occur inside the storm. A Cyclone has the potential to produce much more rain and flood than a regular hurricane could.
The strongest winds in a tropical cyclone are located along and near the eye wall, or center of circulation. A well-defined cyclone will usually have an outer edge extending into a range of about 200 miles. This point is called the eye wall because it is where the eye of a tropical cyclone meets the outer edges of advancing warmer air. A warm air convergence tends to create stronger winds over a wider area than cold air does. So on days with higher temperatures, such as in early October, a warm band can develop along and near the eye wall of a tropical cyclone and produce surface winds of up to 160 mph. In contrast, a warm band doesn’t tend to have very strong winds aloft nearly as long as it does along and near the eye wall, and that formation tends to break up rather quickly.
In addition to the differences in wind speeds and directions, there are also significant differences in the height of the clouds above the storm. A hurricane can have the wind speeds and/or direction of travel to hit different levels and distances from the storm. On shorter days, the lowest cloud levels are closer to the ground and the tallest cloud tops are closer to the sky. A hurricane typically makes its approach to land by hugging the coastline and then moving inland to meet with its colder air mass. The cool air mass is warmer, and therefore tends to push back on the warm air mass, forcing it to the top of the storm.
A tornado has essentially the same characteristics as a cyclone. The primary difference is that the cyclone dissipates rather quickly over a short period of time. A tornado usually has the potential to last much longer, however, because it has sufficient low atmospheric pressure to continue generating winds at high intensity for a much longer period of time. A low atmospheric pressure area tends to have a relatively stable surface, although the tornado does move with the wind.
In order to understand the relationship between a Cyclone and a tornado, it’s important to understand how the weather system is structured around the Earth. A large area of cold air mass moves eastward into the north Pacific Ocean while warm air mass flows from the Caribbean and southern tropical regions into the northern hemisphere. As the warm air pushes into the southern hemisphere, the moisture increases in elevation and the wind speeds decrease.
A Hurricane typically originates from a warmer air mass moving toward the ocean while tropical cyclones move from the ocean to the Gulf of Mexico. The difference in occurrence between a Cyst and a Hurricane is that a Hurricane can move in a northeasterly direction across the Atlantic Ocean while tropical cyclones move in a southerly direction. When a Hurricane or Cyst affects land, a low-pressure area develops that leads to the development of severe thunderstorms. These thunderstorms may not develop into a tornado. Although rare, there have been documented tornadoes in areas of the northern and western United States caused by a sudden warm-up of surface temperatures caused by a tropical cyclone.
In order to forecast the development of a possible cyclone, it’s necessary to track wind records in the vicinity of the potential storm. This information allows forecasters to determine whether the potential for a cyclone will be visible from their location. If there is a potential for a tropical cyclone to produce winds of more than just 100 miles an hour, then a hurricane or typhoon may be expected somewhere in or near this path. Recognizing the signs of a potential Hurricane or Cyclone can help to increase your chances of avoiding the devastation these storms can cause.