In late August 2012, Tropical Storm Isaac hovered over the Caribbean Sea, taking aim at populated areas. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite captured this image around 1:40 p.m. Eastern Daylight Time on August 23. In this natural-color image, coastlines and national borders are delineated in black.
At 2:00 p.m. EDT on August 23, shortly after MODIS took this picture, the U.S. National Hurricane Center (NHC) reported that Isaac had maximum sustained winds of 40 miles (65 kilometers) per hour. Although Isaac did not appear well organized on August 23, it showed signs of strengthening. By 8:00 a.m. EDT on August 24, Isaac’s wind speeds had increased to 50 miles (80 kilometers) per hour, and a hurricane watch was in effect for Haiti.
At 2:00 p.m. EDT on August 24, the NHC issued an advisory on Tropical Storm Isaac, reporting that the organization of the storm has improved and advising that, although rapid intensification is not expected, the storm could reach hurricane strength by the time it reaches Hispaniola. Although interaction with land should weaken the storm again, conditions are favorable for additional strengthening over the Gulf of Mexico before the storm makes landfall in the United States.
Isaac is a large storm, with a large reach. Heavy rains and tropical storm or hurricane strength winds are expected to affect Haiti by August 24, Cuba by the morning of August 26, southwestern Florida by August 27, and Alabama and Mississippi by August 29. According to the Global Disaster Alert and Coordination System (GDACS), Tropical Storm Isaac can have a high humanitarian impact. Haiti, in particular is at risk, where winds up to 120 km/h (74 mph) are expected. Up to 1.07 million people in that country may be affected by wind speeds of hurricane strength or above and, 10.51 thousand people are living in coastal areas below 5 meters and may be affected by storm surge.