Chapter 20 Section 4 Hurricanes and Winter Storms

Describe the origin, life cycle, and behavior of weather systemsObjectives:-Explain the formation and effects of hurricanes, and the measures taken to mitigate their damage-Describe the weather conditions associated with mid-latitude lows during winter

Hurricanes:

• Large rotating storm of tropical origin• Sustained winds of at least 119 km/hr• Energy source – heat from surface ocean

water• In the Pacific – typhoons

Structure and Formation

• Spiral structure

• Outer edge of system, rain and wind are mild– Increase as winds spiral toward the center of

storm (low pressure)

Define: Eye, Eye Wall, Feeder Bands

Which Hurricane is this? How do you know

Formation

• Must have a supply of warm, moist air

• Water evaporates and condenses within storm clouds

– This releases heat energy which fuels the storm– Originates in the tropics

Formation:

Coriolis EffectMerry Go Round

-Coriolis Effect:Causes air at the surface to rotate counter-clockwise in the N. Hemisphereclockwise in the S. Hemisphere

Storm Surge

• A large volume of water pushed onto shore as a result from hurricane winds

• Exacerbated (intensified) during high tides

Hurricane Tracking Data

• http://www.csc.noaa.gov/hurricanes/#