Hurricane+Development+Group+1

=Hurricane Development= By Tom R. & Rachel L. //Hurricanes go through many different stages. All hurricanes start off as a tropical depression and then while they strengthen some will become tropical storms. If the storm strengthens further, then it will become a hurricane. If the storm hits the hurricane status, there are 5 categories that can rate the intensity of the storm.//

Tropical Depressions

 * A typical tropical depression contains wind speeds of 23-39 mph.
 * Little organization
 * No real "cyclonic" motion
 * Made when thunderstorms come togeather
 * From satellite appears as though it is just a large thunderstorm.

As one can see it looks just like a bunch of thunderstorms not a hurricane in any way.

Tropical Storms

 * A tropical depression contains winds of 39-73 mph
 * Usually move westward at about 10-20 kmph
 * Can cause damage, mainly in the way of heavy rainfall
 * Also known as tropical cyclones and typhoons
 * Weaken over land

Hurricanes

 * A storm that has evolved so that the wind speeds are over 73mph
 * Happens when surface pressure drops
 * Very clear rotation around center of hurricane
 * Earths strongest tropical cyclones
 * Centered around the eye of the hurricane
 * Rated acording to their wind speed
 * Scale ranges from 1-5 (5 being the strongest hurricane and 1 being the lowest hurricane)



Category 1
This is an image of Hurricane Lili which occured in 2002. As one can see this hurricane has distinguished circular motion but has not developed a clear eye to rotate around yet.
 * 74-95 mph winds
 * Storm surge generally 4-5 feet above normal
 * Main damage done to bushes and unanchored mobile homes--no real damage to other structures
 * Minor pier damage

Category 2
Compared to the image of Hurricane Lili, this picture of Hurricane Isabel in 2003 shows that the hurricane is developing more of an eye and is gradually becoming a more organized storm.
 * Winds of 96- 100 mph
 * Storm surge 6-8 feet above average
 * Noticeable damage to shrubs and trees, serious damage on some road signs, and minor damage to roofing
 * Marinas flood
 * Evacuation of some coastal residences and close islands required

Category 3
As you can see, the eye of this storm is gradually getting more refined than the category 2 hurricane's eye.
 * Winds of 111-130 mph-- serious damage to trees and signs, and some damage to roofing, windows, and doors
 * Storm surge 12 feet above normal
 * Major flooding at coast and destruction of small structures near coasts
 * Major erosion of beaches

Category 4
Not only is the hurricanes eye getting more refined, but the outer walls of the hurricane is getting more organized while it becomes a more powerful storm
 * Winds of 131-155 mph
 * All shrubs, trees, and signs down
 * Extreme damage to roofing, windows, and doors.
 * Roofs collapse
 * Storm surge 13-18 feet above normal
 * Flat ground at most 10 feet above sea level flood as far as 6 miles inland
 * The eye is defined

Category 5
Compared to the category 4 hurricane, one can see that this hurricane's eye is much larger and the outer walls of this hurricane are much more organized than the category 4 hurricane.
 * Winds more than 155 mph
 * serious damage to roofs
 * All signs down and most trees down
 * Storm surge higher than normal by 18 feet
 * Major damage to structures less than 15 feet above sea level within 500 yards of the coastline
 * Massive evacuation of areas low to the ground within 10 miles of
 * The eye is clearly defined

Factors in Hurricane Development

 * Warm ocean temperatures are a fuel sorce for hurricanes when above 80 degrees Fahrenheit
 * Easterly wind flow support the hurricane. Westerly winds help make sure that there is no shearing, which means tearing thunderstorms.
 * Rotation. Without rotation, the wave is only an area of low pressure.
 * All of these factors are necessary for the storm or hurricane to stay strong

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