Shelf clouds ahead of derecho in Chicago area

Shelf clouds ahead of derecho in Chicago area

Severe storms, called a derecho by meteorologists, moved through Chicago this morning. Ahead of the storm, people sighted a shelf cloud in Illinois.Shelf clouds often form at the leading edge of a gust front or outflow boundary from a thunderstorm, or strong winds

Heavy Rain in Namibia and South Africa

Heavy Rain in Namibia and South Africa

In early May 2011, more rain fell in one day in parts of Namibia and South Africa than typically falls in an entire year. For several months, unusually heavy and persistent rains have soaked western Africa and filled rivers and basins that have been quiescent for