Derecho comes from the Spanish word in adjective form for "straight" (or "direct"), in contrast with a tornado which is a "twisted" wind. The word was first used in the American Meteorological Journal in 1888 by Gustavus Detlef Hinrichs in a paper describing the phenomenon and based on a significant derecho event that crossed Iowa on 31 July 1877.
In many cold regions, heavy snow over the winter usually stays un-melted for sometime. There are also mountains that have ice on top of them. Sometimes the ice suddenly melts when the temperature rises, resulting in massive movement of water into places that are usually dry.
Drought and flooding are the most deadly natural phenomenon. Credit: sxc.hu Hurricanes, tornadoes, and earthquakes might seem like the most dangerous natural hazards you could ever face, but floods and droughts actually kill more Americans over time.
A storm that produces a significant thickness of glaze ice from freezing rain is often referred to as an ice storm. Although these storms are not particularly violent, freezing rain is notorious for causing travel problems on roadways, breaking tree limbs, and downing power lines from the weight of accumulating ice.
An ice storm is a type of winter storm characterized by freezing rain, also known as a glaze event or, in some parts of the United States, as a silver thaw. The U.S. National Weather Service defines an ice storm as a storm which results in the accumulation of at least 0.25-inch (6.4 mm) of ice on exposed surfaces.
Most lightning bolts exhibit the following phenomena: a leader leaves a point in the cloud and travels about 50 m at a very high speed of around 50 000 km/s. A second leader then leaves the same point, follows the previous path at comparable speed, goes beyond the final point of the first leader by an approximately identical distance, then disappears in turn.
The clouds that form prior to and during these events are called cumulonimbus clouds. Hail, lightning, thunder and tornadoes are all products of thunderstorms. What causes a thunderstorm to occur? Thunderstorms originate when the atmosphere presents a certain set of conditions.