Cyclones, hurricanes and tornadoes are meteorological phenomena that correspond to major atmospheric changes, such as very strong winds accompanied by torrential rains and even snow or precipitation of hail. In certain climatic seasons changes of temperature and atmospheric pressure that justify these phenomena can occur.
Meteorologists classify windstorms when the winds reach 70 km / hour and storms when they reach 100 km / hour. Both are accompanied by little rain and occur when two areas with very different atmospheric pressure meet. With winds above 117 km / hour the theme phenomena of this article occur.
Cyclones, hurricanes or typhoons
These are names usually used to designate strong tropical cyclones. When large portions of air with low atmospheric pressure form over the oceans, in the tropics, the formation of an upward air column occurs because the warm air is light.
As this column of air rises, the winds that move horizontally begin to make it spin and the water vapor contained in the column of hot air cools and condenses, forming droplets of water and clouds. Over a few days, this process is intensifying and, with it, thunder and torrential rain.
If the winds blowing around come too fast, the atmospheric pressure inside the ascending column of air will fall rapidly, forming what is conventionally called the eye of the hurricane . The occurrence of hurricanes can last for a few days and they can move at a speed of 19 to 32 km / h.
This phenomenon is called a hurricane when it forms in the Atlantic Ocean. However, when it forms in the Indian and Pacific oceans, it is called a typhoon .
Cyclones or hurricanes can be classified within a scale called Saffir-Simpson, which takes into account the atmospheric pressure in the eye of the hurricane, the speed of the winds and the intensity of the storms. This scale ranges from 1 to 5 and is used to measure the destructive power of a hurricane. See below.
- The category 1, minimum , indicates winds of 119 to 152 km / h;
- A 2, moderate , has winds of 153 to 177 km / h;
- A 3, wide , with winds that reach from 178 to 209 km / h;
- A 4, extreme , which indicates winds between 210 and 249 km / h;
- A 5, catastrophic , with winds that reach more than 249 km / h.
Tornadoes are the worst type of weather disturbance one can have. They form when a column of upward air connects simultaneously to a cloud charged with moisture and to the ground. They are atmospheric vortices (swirls) and their winds can reach 500 km / h.
Although they can often be confused with hurricanes, there are many differences between them. The main thing is that tornados only form on the continents, are more intense and short, while hurricanes originate in the oceans of the tropical regions, are less intense, but last longer.
When a tornado passes over a region, it usually pulls pieces of objects and even trees, carrying them; so when it hits some inhabited area, it gets even more dangerous.
The strength of a tornado is measured by the Fujita scale, variable from zero to five and that measures the intensity of the caused destruction.