The old English proverb, “March comes in like a lion and goes out like a lamb,” often seems only half right. March does come in like a lion, but it often goes out like a lion as well. Why is it so windy in the spring?
“Wind is the movement of air caused by uneven heating of the atmosphere,” states weather.com. In the spring, the Earth rotates toward the sun, which allows the ground to warm. However, the sun hits different parts of the Earth at different angles. Oceans, mountains, and plains warm up at different rates. This creates pockets of warm and cold air.
The gases in the Earth’s atmosphere behave differently when temperatures change. This allows high air pressure areas and low air pressure areas to form. As hot air rises, the gases spread out and form a high-pressure area. However, cold air falls, and this causes the gases to crowd together, forming a low-pressure area. When the weather person points out a high-pressure area on the map, it usually means good weather. A low-pressure area can precede a stormy time.
Nature produces a strong drive to equalize the pressures. The gases in the high-pressure area rush toward the low-pressure area. This causes wind. The closer the areas are to each other, the faster the high-pressure area rushes toward the low-pressure area. This causes the winds to increase in speed and force.
The weather is more unsettled in the spring. As well as being caused by the uneven warming of the Earth, the stormy weather is also caused by cold air still flowing down from the polar regions. At the same time, warm tropical air is trying to move north. These two contrasting powers often meet in battle, which causes the storms in March, April, and May. By June, the battle has been won by the tropical air masses flowing north. Storms and winds decrease. The weather stabilizes and usually only produces thunderstorms and occasional droughts.
Perhaps the proverb should be changed to read, “March comes in like a lion and doesn’t go out like a lamb until June.”
Submitted by Bonnie Hinman
