How Hurricanes Work
Roger Robertson
Samuel Olson
Overview
 Hurricane season June
1st – November 30th
 Also called cyclones or
typhoons
Forming
 Forms in warm water
 Tropical Region
 Most Atlantic
Hurricanes form off the
west coast of Africa
http://science.howstuffworks.com/hurricane2.htm
Parts of a Hurricane
 Eye - the low pressure, calm center of
circulation
 Eye wall - area around the eye with the
fastest, most violent winds
 Rain bands - bands of thunderstorms
circulating outward from the eye that are
part of the evaporation/condensation cycle
that feeds the storm
Stages
 Tropical depression - swirling clouds and
rain with wind speeds of less than 38 mph
 Tropical storm - wind speeds of 39 to 73
mph
 Hurricane - wind speeds greater than 74
mph
Category Wind Speed
Effects
1
74 to 95 mph
Storm surge 4 to 5 ft above normal
Some flooding
Little or no structural damage
2
96 to 110 mph
Storm surge 6 to 8 ft above normal
Trees down
Roof damage (shingles ripped off)
3
111 to 130 mph
Storm surge 9 to 12 ft above normal
Structural damage in houses
Mobile homes destroyed
Severe flooding
4
131 to 154 mph
Storm surge 13 to 18 ft above normal
Severe flooding inland
Some roofs ripped off
Major structural damage
5
>155 mph
Storm surge at least 18 ft above normal
Severe flooding further inland
Serious damage to most wooden
structures
Weather Alerts
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Tropical-storm watch
Tropical-storm warning
Hurricane watch
Hurricane warning