Weather and Climate


World Weather

On a global scale, weather is the movement of heat, water and electrical charges from one place to another. Sunlight provides the energy to drive the system.

  • The sun's heat evaporates billions of tons of water from the surface of the oceans. This water vapor forms clouds.
  • The sun shines more directly on the equator and tropics than on the poles, causing major differences in temperature. These temperature differences drive the winds.
  • The movement of all this water vapor and air helps create imbalances in electrical charges in the air and on the ground. More than a million bolts of lightning each day bring the electrical charges into balance.

Washington Weather

Here in Washington the shape of the ground has a major effect on the weather. On the west side of the Olympic Mountains, the wind pushes moist air upward against the sides of the mountains. The moist air cools as it rises, forming clouds and releasing moisture in the form of rain, snow or hail. The heavy precipitation on the west side of the Olympics leads to the growth of dense rain forests. The Cascade Mountains produce the same upward movement and release of moisture when the air continues to the east. By the time the air moves east of the Cascades, much of the moisture has been squeezed out, causing desert-like conditions.

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