Tropical Storm Katrina had just become the eleventh named storm of the 2005 Atlantic Hurricane season when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured this image on August 24, 2005, at 11:50 a.m., Eastern Daylight Savings Time. The storm formed late on August 23 and developed quickly into a tropical storm by 11 a.m. the next morning. By the time MODIS acquired this image, the storm was just starting to take the recognizable swirling shape of a hurricane. Katrina had winds of 64 kilometers per hour (40 miles per hour) and was expected to get stronger as it approached the south Florida coast, possibly becoming a Category 1 hurricane before coming ashore.

A more serious danger is Katrina’s rains. The storm is moving slowly, just 13 km/hr (8 mph), and it is expected to slow as it moves over land. This means that Katrina’s heavy rains will linger longer over one area, dumping 15-25 centimeters (6-10 inches) of rain over Florida and the Bahamas and possibly up to 38 cm (15 inches) in some regions, the National Hurricane Center warns.