Wind, Rain and Hurricanes
Name: Becky S.
My teacher said that when a hurricane comes, the east of the hurricane always
gets the wind and the west of the hurricane always gets the rain. Why?
Your teacher is basically correct. The area of the hurricane 45 degrees to the right of the
direction that it is traveling usually has the strongest winds. This is true of most low
pressure systems and is a result of pressure isobars (lines of constant pressure) being
compacted together in that area. The closer the isobars are together, the greater the wind
speed tends to be. Exactly why this occurs is harder to explain without becoming much more
Heavy rain can occur in almost any area of a hurricane, except in the eye and is almost always
a result of thunderstorms spawned
in bands by the hurricane. These bands spiral out of the storm as it rotates (you can see that
easily on a satellite photo). Your teacher may have said that "the west of the hurricane
always gets the rain" because it is usually the western side of an Atlantic Ocean hurricane
(which usually moves westward) that makes landfall against the east coast of the Unites States,
Central America, or one of the islands in the Caribbean.
However, hurricanes that form in the southern Pacific Ocean can travel eastward, with the
eastern part of the storm making landfall
on the west coast of Mexico (a couple of hurricanes have done that already this year). Some
Pacific Ocean hurricanes travel westward, even as far as Hawaii or beyond, and these can make
landfall on the east coasts of the Hawaiian islands.
David R. Cook
Atmospheric Research Section
Environmental Research Division
Argonne National Laboratory
Hurricanes are violent storms that behave somewhat differently from each other. Lots of
things affect how a particular storm will behave. Sometimes the heaviest rain may be on
the eastern side of the storm, sometimes it may be on the west, or north, or south. When
the storm is over the ocean, the rain band around the storm is pretty even on all sides.
It is when the storm strikes land that there are big differences in winds and rainfall,
depending on where you are located with respect to the storm.
As the storm moves over land, its source of energy, which is the warm and humid air from the
ocean is left behind, and the storm weakens and dies. But it can cause major flooding and
wind damage as it weakens.
Wendell Bechtold, forecaster
Meteorologist, National Weather Service
Weather Forecast Office, St. Louis, MO
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Update: June 2012