Rain and Floods
When the droplets which form clouds become large enough they fall to the ground as rain. As the soil and plant life reach the maximum amount of water they can absorb, the remaining water runs off the land in such huge amounts that the streams, ponds, and reservoirs can no longer hold this excess water. This runoff is sometimes increased by melting snow. As this excess water fills the rivers, a flood can be the result. When a flood is the result of an excessive amount of rainfall, a “flash flood” may occur. Flash floods can strike with little or no warning.
Coastal floods can be the result of high tides induced by strong winds which move over the ocean surface or by tsunamis.
Snow and Avalanches
Snow is not frozen rain but is made of water vapor which forms ice crystals in the shape of flakes. These flakes are very small but when combined together they can cause problems for the land and air travelers.
Blizzards, which are most common in the western parts of the United States but not totally unknown to other areas, are the combination of heavy snowfalls accompanied by strong winds and extreme cold. The snowfall and winds last for a period of at least three hours and some may last for days. The winds during a blizzard can reach speeds of over forty miles per hour and reduce the visibility to near zero. People and livestock have been killed during blizzards and buildings, burdened with the weight of the snow, may collapse. Blizzards can essentially paralyze an entire area like the great blizzard of March 1888, which lasted for three days and brought the eastern portion of the United States to a stand still.
Avalanches occur when a large amount of snow slides down a mountainside. Avalanches are responsible for the deaths of nearly two hundred people per year. They are quick, powerful snow slides, which can be triggered by a sudden movement or loud noise. Due to the swiftness and surety of the results of an avalanche, they have been given the notorious nickname of “white death”.
Winds & Tornadoes
Tornadoes are most likely to form as cold air moving towards the south meets warm moist air moving north. As these two air masses meet, the colder air pushes under the warmer air, which begins to spin as it rises.
Thunder, lightning, rain, and hail accompany this storm. The high winds create a terrific noise which mimics the sound made by a jet engine or freight train. As this air continues to spin, the result may be a funnel shaped cloud which whirls at high speeds. The center of a tornado can reach a speed of more than two or three hundred miles per hour. Tornadoes are powerful enough to lift buildings off their foundation and to cause much loss of property and life. Tornadoes are the fastest wind storms on earth.
The vast plain areas from Texas to the Canadian border have been nicknamed “tornado alley” by meteorologists, for this is where most tornadoes strike in the United States. The high period for the formation of tornadoes is during the months of April, May, and June.
Hurricanes
Hurricanes form over the ocean, creating huge waves, which pile up along the shore. Hurricanes are wind storms, with a large spiral pattern, which creates giant whirlwinds. These whirling winds move around a calm center called the eye. These tropical cyclones, can be as wide as fifty miles across and can pack winds of more than seventy-five miles per hour. The direction of the storm on the other side of the eye, will be in the opposite direction of its original approach.
Hurricanes are all given names which have generally been feminine in gender. Only recently have hurricanes been named after males as well.
Thunderstorms & Lightning
When moist, warm air is quickly cooled the result may be a thunderstorm. A thunderstorm forms as winds push upward into the center of a cumulus cloud thereby forcing cold air to the outside of the cloud. As this happens, raindrops form and fall but are quickly pushed back into the center of the cloud by these strong, upward winds. Electricity which is produced by this movement, builds up and produces lightning. Lightning has been known to strike trees, buildings, and people. Fires, serious injury, or death can be the result of an encounter with lightning. Finding shelter from the rain and lightning is the best way to stay safe during a thunderstorm.