MODIS true color image (bands 1, 4, 3) of the U.S. Midwest, 17 January 2005.
Heavy rain and snow have swollen the rivers of Indiana, Illinois, and Kentucky, pushing many past flood stage during the first two weeks of January 2005. The flooding occurred after several days of rain and snow fell on the already saturated ground of the U.S. Midwest. Since the water could not be absorbed into the soaked ground, it ran off as flood water. The storms were followed by warm temperatures, which melted the snow and produced further flooding. By January 17, some of the flooding had started to recede, but large tracts of land along the Ohio and Wabash Rivers were still under water.
The Aqua MODIS instrument captured the image of the flooded rivers on January 17. The Ohio and Wabash Rivers are the most noticeably flooded, but many other rivers are also much larger than they are under normal conditions. On November 25, 2004, the Wabash River measured less than 3 pixels across in the 500-meter-resolution MODIS image. On January 17, 2005, the river spanned 18 pixels at its widest point, increasing its width from approximately 1.5 kilometers to 9 kilometers. The Ohio River similarly grew to a width of 13.5 kilometers.
Floods along the Ohio are not unusual, but the timing of this flood is. The Ohio River and its tributaries often flood in the spring when winter's snow melts and runs into regional rivers. This flood is occurring in the middle of the winter, which is unusual.
Text and image courtesy of NASA's MODIS Land Rapid Response Team.