The remnants of Tropical Storm Erin unleashed heavy rain on Central Oklahoma on August 19, 2007. The rain brought wide-spread flooding that killed at least six people, reported CNN on August 19. Rivers around Oklahoma City were still swollen on August 21, when the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured the top image.
The image was made with a combination of infrared and visible light to increase the contrast between water and land. Though water is normally dark blue or black in this type of image (the color of the reservoirs around Oklahoma City in the lower image), the North Canadian, Canadian, and Washita Rivers are light blue. This color is common in mud-laden flood water or water-logged mud, since the dirt scatters light that the water would otherwise absorb.
A band of pale blue and white clouds from another storm system (not Erin) covers the western reaches of the flooded rivers. Oklahoma City, with its reflective buildings, spreads silver-gray across the plain. The surrounding farmland is bright green, while non-vegetated land is rosy tan. The worst of the flooding visible in this image appears to be northwest of Oklahoma City along the North Canadian River.
Erin’s rains fell on a region that was already soggy. The summer of 2007 was the wettest on record in Oklahoma, said the Oklahoma Climatological Survey. Between June 1 and August 20, central Oklahoma (the region shown in these images) received 23.23 inches of rain, 14.45 inches above normal.
NASA images courtesy the MODIS Rapid Response Team at NASA GSFC, which provides daily images of the United States.
