Our Changing Weather
Some days are warm and sunny, others cold and raining. Everyday the weather is different from the day before. What makes weather patterns happen? There are different air masses at the frozen poles, the warm equator area and the middle land continents. When these air masses meet they produce different types of weather.
The cold, dry air masses move from the polar regions towards the moving warm, moist masses that are moving from the equatorial area. When these masses meet there is a change in the atmosphere, which causes a change in weather.
There are the two main weather fronts. A front is a boundary line between 2 different air masses. One is called a cold front, the other is called a warm front. These fronts can combine to make an occluded front where the cold air over takes the warm air. A stationary front is another combination of a cold and warm front that stays in place a long time It can bring rainy weather. A dry line separates a dry air mass from moist air mass. It makes the weather conditions vary in temperature one different sides of the line.
A low pressure is a twirling mass of warm moist air that is represented by a red L. Tropical storms and hurricanes develop from a low pressure. A high pressure is cool, dry air that is represented by a red H. A high pressure can bring fair, sunny weather and light winds.