lighning and Tornados
How tornados are formed
Tornadoes are one of the most powerful and deadly weather phenomena on land. They can destroy entire town and fling debris over great distances. However, how does a tornado form? The answer lies in the atmosphere and air pressure.
Weather is created by changes in the temperature and pressure of the atmosphere. Tornadoes are formed when both high pressure and low pressure air interact. A tornado happens in the same way a whirlpool in your sink or bath tub happens. A low internal pressure draws in high pressure air to form the vortex and eventually the tornado.
Tornadoes are normally formed when a thunderstorm occurs. The most common type of thunderstorm for forming tornadoes is the supercell. This is because this type of storm already has rotation occuring within it called a mesocycle. The tornado starts forming when a downdraft brings the mesocycle down near the grown starting the creation of a vortex.
The next step of the cycle starts when cloud wall is formed. This happens when the vortex starts drawing down the cloud into a funnel. The most dangerous part of the tornado is not the visible part its the winds created by the high pressure air being sucked into the tornado. This is what creates the destruction path scene after a tornado passes.
Read more: http://www.universetoday.com/52055/how-tornadoes-are-formed/#ixzz2yPJv1qtL
LIGHTNING
In the case of lightning cloud formation is seen as the main way that the separation of charges occurs. This is because clouds are largely made of condensed water vapor. Water has many interesting traits and one of them is polarizing charges on the molecular level. Scientist believe that as water changes states during cloud formation an extra charge is developed and separated by water molecules. Some hypotheses see the charges so separated that all of one side of a cloud can be one charge.
There is also the fact that there is a corresponding build up charge on the ground or in opposing clouds. This build up charge is what creates the conditions for lightning
Read more: http://www.universetoday.com/77083/how-is-lightning-formed/#ixzz2yPNwLr7I
Read more: http://www.universetoday.com/77083/how-is-lightning-formed/#ixzz2yPNmF6qV
water spouts
Tornadoes are violent thunderstorms gone wild. But is a waterspout a tornado? By definition - A tornado is vertical column of spinning air from a cumulonimbus cloud that contacts the ground. So is a waterspout a type of tornado?
Answer:
Waterspouts are similar to tornadoes, but they form in a different manner. Generally, waterspouts are given the honor of being called a "tornado over water". But waterspouts are not truly given the name of a real tornado until they reach land.
The Two Types of Waterspouts
Water spouts can start as tornadoes over land. If they move over a body of water, they are classified as tornadic. This type of waterspout can be fairly destructive.The second type of waterspout is formed over water initially due to warm temperatures in the lower atmosphere along with high humidity. Fair weather waterspouts are generally not as dangerous and are more common than tornadic waterspouts. However, boaters and people who live near larger bodies of water should take waterspout warnings and
Hurricans
Hurricanes
What is a hurricane?
A hurricane is a huge storm! It can be up to 600 miles across and have strong winds spiraling inward and upward at speeds of 75 to 200 mph. Each hurricane usually lasts for over a week, moving 10-20 miles per hour over the open ocean. Hurricanes gather heat and energy through contact with warm ocean waters. Evaporation from the seawater increases their power. Hurricanes rotate in a counter-clockwise direction around an "eye" in the Northern Hemisphere and clockwise direction in the Southern Hemisphere. The center of the storm or "eye" is the calmest part. It has only light winds and fair weather. When they come onto land, the heavy rain, strong winds and large waves can damage buildings, trees and cars
How do hurricanes form?
Hurricanes only form over really warm ocean water of 80°F or warmer. The atmosphere (the air) must cool off very quickly the higher you go. Also, the wind must be blowing in the same direction and at the same speed to force air upward from the ocean surface. Winds flow outward above the storm allowing the air below to rise. Hurricanes typically form between 5 to 15 degrees latitude north and south of the equator. The Coriolis Force is needed to create the spin in the hurricane and it becomes too weak near the equator, so hurricanes can never form there
Tsunami's
What is a tsunami?
A tsunami is a series of ocean waves with very long wavelengths (typically hundreds of kilometres) caused by large-scale disturbances of the ocean, such as:
- earthquakes
- landslide
- volcanic eruptions
- explosions
- meteorites
These disturbances can either be from below (e.g. underwater earthquakes with large vertical displacements, submarine landslides) or from above (e.g. meteorite impacts).
Tsunami is a Japanese word with the English translation: "harbour wave". In the past, tsunamis have been referred to as "tidal waves" or "seismic sea waves". The term "tidal wave" is misleading; even though a tsunami's impact upon a coastline is dependent upon the tidal level at the time a tsunami strikes, tsunamis are unrelated to the tides. (Tides result from the gravitational influences of the moon, sun, and planets.) The term "seismic sea wave" is also misleading. "Seismic" implies an earthquake-related generation mechanism, but a tsunami can also be caused by a non-seismic event, such as a landslide or meteorite impact.
Tsunamis are also often confused with storm surges, even though they are quite different phenomena. A storm surge is a rapid rise in coastal sea-level caused by a significant meteorological event - these are often associated with tropical cyclones