This leads air pressure to rise even higher, to the point where the weight of the air counteracts the intensity of the storm's updrafts in the core. Air begins to descend on the storm's core, forming a mainly rain-free zone around the newly formed eye. As the atmosphere above the center of circulation becomes more stable, strong winds begin to surround the eye. These are called "outflow boundaries" and they extend far out from the center, bringing dry air from the ocean up into the storm's circulation.
The wind speed inside the eye increases as the air is no longer being pulled upward by the storm's core. When the wind reaches 70 miles per hour (110 km/hr), it starts to tear at the land and sea outside the eye, creating destructive waves known as "storm surges." This is why it is important not to get in the way of a hurricane or other powerful storm system. It needs all the space it can get to move things around efficiently, so don't get in its way!
Hurricanes need warm oceans and low atmospheric pressures for their existence. Therefore, they tend to form in regions with these characteristics, such as the Atlantic Ocean and Caribbean Sea. A hurricane cannot form if both of these conditions are not present. However, a region might have one or more hurricanes every season because the atmosphere can temporarily prevent them form.
Air begins to descend on the storm's core, forming a mainly rain-free zone—a freshly formed eye. Winds within this zone are relatively calm and usually from the south or southwest. Thunder and lightning can be heard but not felt during an air mass move over land.
The eye is the most visible part of a hurricane or typhoon. They are only visible in daylight with no clouds or wind speed indicators available for scale. However, based on atmospheric pressure changes associated with them, we can estimate their size as a factor of five differences between peaks and valleys provides a good rule of thumb. Eyes can also be seen on other types of storms such as typhoons and tropical depressions.
An eye is defined as a region of calm, somewhat stable air within a turbulent atmosphere. The name comes from the fact that when viewed from above, it appears as a spot without surrounding disturbance. Within the eye, the air is still but not completely calm; any turbulence here or there is due to small waves moving through the air. Outside of the eye, winds become stronger as they approach the center, where there is less air flowing over the surface.
People often report seeing stars within a tropical cyclone's eye.
Convection causes bands of vapor-filled air to begin revolving around a common core in a tropical cyclone. Then, just barely, it overtakes their strength: air begins to gently drop in the heart of the storm, creating a rain-free zone. This is a brand-new eye.
The heat and moisture from the sun cause clouds to evaporate quickly in warm climates like Africa's Western Cape. The rising hot air creates its own wind called an anticyclone that brings more clouds and rain over the region. This process repeats itself until all the water has been converted into cloud and ocean currents change direction due to the rotating earth. The result is the appearance of a new cyclone or hurricane far away from any landmass.
Hurricanes are powerful storms that can cause immense damage and death when they strike land. They develop in warm oceans with abundant moisture who's surface temperature is above 75 degrees Fahrenheit. Tropical depressions are the low-pressure centers that form at sea before turning into hurricanes. They are identified by black skies and strong winds that rotate around the center
Tropical depressions can become hurricanes very easily because there is much water involved in their formation. However, once a depression enters an area with landmasses near the equator, it becomes more difficult because there are now two different environments fighting each other for dominance - air and water.
When part of the rising air in the eye wall is driven towards the center of the storm rather than outward, where most of it travels, an eye forms. This air is pouring in from all sides and heading for the center. Because of this convergence, the air actually sinks into the eye. It becomes dense enough for clouds to form below it.
The direction that the eye moves is generally due to which way the wind is blowing elsewhere on the surface of the planet. If the wind is coming in from many directions, as it is typically does in hurricanes, the eye will move in several different directions depending on the strength of the winds from different angles.
However, if one were to measure the angle between the current location of the eye and some fixed point outside of the hurricane's influence, such as another large storm or land mass, then that would indicate which way the storm is moving relative to that fixed point.
It is important to understand that the movement of the eye is not constant - it varies with the size of the storm, so even though it may look like it is going in one direction, it could be moving in another at any given moment.
Also, keep in mind that satellite images show us only part of the whole situation.