August 2007 was the wettest month ever recorded for many places in Minnesota, Iowa, and Wisconsin, with rainfall totals ranging from 23.86 inches in Hokah, Minnesota, to 12.79 inches in Winona Dam, Minnesota, said the National Weather Service. While the entire month was rainy, much of the rain fell on August 18-20, when several thunderstorms rolled across the region. The thunderstorms triggered disastrous flooding in several Midwest communities, including La Crosse, Wisconsin. A little over 10 inches of rain fell in La Crosse in the 24-hour period that spanned August 18 and August 19, and flash floods resulted. Combined with rains from the rest of August, this rainfall let La Crosse set a new monthly precipitation record of 17 inches.
By August 27, when the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) captured the top image, the floods had largely retreated, though visible signs of flooding remained. Compared to the lower image, acquired on September 7, 2006, the landscape to the west of the Mississippi River is pocked with pools of water. The city of La Crosse, the bright white and gray grid on the east side of the river, appears to have dried out. The city appears much as it did nearly a year earlier with no visible sign of flooding.
You can download a 15-meter-resolution KMZ file of the 2007 image of La Crosse suitable for use with Google Earth.
NASA image created by Jesse Allen, using data provided courtesy of NASA/GSFC/METI/ERSDAC/JAROS, and U.S./Japan ASTER Science Team.