Guest Author - LeeAnn OLeary
How is a hurricane formed?
A hurricane starts off as a regular thunderstorm. Most of these
storms start off the coast of West Africa and then move over
the warm tropical waters and this is one of the ingredients in
the recipe for a hurricane. The difference is that the thunderstorms
start to rotate once they run into the converging winds. It takes an
incredible amount of energy for a hurricane to be created. Without
the right factors a hurricane will not be created. A hurricane needs
warm water to form. Without warm water you will not have a hurricane.
To be exact the water temperature needs to be at least 80 degrees.
A hurricane also needs to have a constant flow of warm, moist air.
Most hurricanes start of as a regular thunderstorm. When the
thunderstorms move over the warm and tropical water of the ocean
it then has the fuel it needs to become a hurricane. This storm has
to go through some stages before it becomes a hurricane though.
The storm is first classified as a tropical disturbance. The storm is
then classified as a tropical depression if it is able to hold
itself together for a day. Next its classified as a tropical depression
if it has rain and wind speeds that are less than 38 miles per hour.
If the storm continues to strengthen it then becomes a tropical storm.
A tropical storm also has rain and the winds are now at speeds of 39
to 73 miles per hour. Once the storm strengthens further and the winds
are stronger than 74 miles per hour it is then classified as a hurricane.
Why are these factors important in the development of a hurricane?
A thunderstorm can only turn into a hurricane if it has a constant
cycle of warm and humid air from the ocean. A hurricane also needs
converging winds at the surface and the same speed of wind
at higher altitudes. A hurricane also needs a difference in air pressure
between the surface and the higher altitude. Without any of these
happening a hurricane cannot form. You often hear the words "wind
shears" when forecasters are talking about a hurricane weakening.
Wind shears is the result of the high altitude winds not blowing at the
same speed at all the levels of the storm. When this happens it causes
the storm to become disorganized and weaken. A hurricane is an
interesting process and actually requires the right conditions at the
right time to form.