WW2010
University of Illinois

WW2010
 
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Online Guides
 
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> meteorology
 
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Meteorology
 
  introduction
 
  air masses, fronts
 
  clouds, precipitation
 
  el nino
 
  forces, winds
 
> hurricanes
 
  hydrologic cycle
 
  light, optics
 
  midlatitude cyclones
 
  severe storms
 
  weather forecasting

Hurricanes
 
  introduction
 
  growth processes
 
  development stages
 
> movement
 
  public awareness
 
  public action
 
  damage
 
  names
 
  global activity
 
  el nino

User Interface
 
  graphics
> text

NOTE: We've guessed that you're not using a client that supports colored tables and have tried to compensate. Low graphics mode looks much better on clients that do... we recommend switching to Netscape 3.0 or Microsoft Internet Explorer.
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Movement of Hurricanes
steered by the global winds

The global wind pattern is also known as the "general circulation" and the surface winds of each hemisphere are divided into three wind belts:

  • Polar Easterlies: From 60-90 degrees latitude.
  • Prevailing Westerlies: From 30-60 degrees latitude (aka Westerlies).
  • Tropical Easterlies: From 0-30 degrees latitude (aka Trade Winds).

[Image: average global wind pattern (45K)]

The easterly trade winds of both hemispheres converge at an area near the equator called the "Intertropical Convergence Zone (ITCZ)", producing a narrow band of clouds and thunderstorms that encircle portions of the globe.

The path of a hurricane greatly depends upon the wind belt in which it is located. A hurricane originating in the eastern tropical Atlantic, for example, is driven westward by easterly trade winds in the tropics. Eventually, these storms turn northwestward around the subtropical high and migrate into higher latitudes. As a result, the Gulf of Mexico and East Coast of the United States are at risk to experience one or more hurricanes each year.

[Image: movement of hurricanes (46K)]

In time, hurricanes move into the middle latitudes and are driven northeastward by the westerlies, occasionally merging with midlatitude frontal systems. Hurricanes draw their energy from the warm surface water of the tropics, which explains why hurricanes dissipate rapidly once they move over cold water or large land masses.



Hurricanes
Terms for using data resources. CD-ROM available.
Credits and Acknowledgments for WW2010.
Department of Atmospheric Sciences (DAS) at
the University of Illinois at Urbana-Champaign.

public awareness