At least 1,100 people in Bangladesh were killed from Tropical Cyclone Sidr, the Associated Press said today, citing the United News of Bangladesh. At least 1,000 fishermen were missing, the United Nations Office for the Coordination of Humanitarian Affairs said today in an e-mailed statement. Some 3.2 million people fled to the country's highlands or went to shelters, the UN agency said.
You can see a high resolution satellite photo in Google Earth showing Tropical Storm Sidr two days ago (before it made landfall). The photo came from the NASA MODIS Terra satellite.
Downpours and staggering winds also spawned a water surge 4 feet high that swept through low-lying areas and some offshore islands, leaving them under water, according to Nahid Sultana, an official at a cyclone control room in the capital, Dhaka.
Cyclones are large revolving tropical storms caused by winds blowing around a central area of low atmospheric pressure. In the southern hemisphere these tropical storms are called cyclones and rotate in a clockwise direction, while in the northern hemisphere cyclones are called hurricanes or typhoons and rotate in an anti-clockwise direction.
Cyclones develop over warm waters in the tropical regions of the oceans where areas of very low pressure are created by air being heated by the sun. This causes the air to rise very rapidly and becomes saturated with moisture that condenses into large thunderclouds.