A slow-moving weather front was responsible for spreading severe storms and flooding across parts of the southeastern and mid-western United States on September 23 and September 24, 2006. The storms occurred when low air pressure over the Central Plains drew warm, humid air up from the Gulf of Mexico. The warm air interacted with strong, upper-level winds. There were numerous reports of tornados, hail, and wind damage on Friday, September 22, across southeastern Missouri and the central Mississippi Valley. On Saturday, September 23, the focus shifted eastward into Tennessee and eastern Kentucky, with the primary threat being damaging winds. Overall, a total of 12 people died as a result of the storms, according to the Associated Press, but most of the fatalities were due to flash flooding in Kentucky.
These images, based on data collected by the Tropical Rainfall Measuring Mission satellite (known as TRMM), show the flood-producing rains. The top image shows rainfall totals for September 23 and September 24 derived from the TRMM-based, near-real-time, Multi-satellite Precipitation Analysis (MPA) at NASA Goddard Space Flight Center, which monitors rainfall over the global tropics. Dark red areas along the Arkansas-Missouri border and stretching into far western Kentucky indicate that rain amounts exceeded 10 inches (about 250 millimeters). Five-inch amounts (130 millimeters, shown in green) stretch from western Oklahoma and up through the Ohio Valley.
The lower image shows an instantaneous snapshot of the actual storms as they swept through the Midwest. The image was taken by TRMM at 18:25 UTC (1:15 p.m. CDT) on September 23, 2006, and it shows the distribution of rain intensity as seen from above. A long line of storms (green area) moves southwest to northeast through the central Mississippi Valley. The storms are followed by a broader area of light rain (broad blue area). Areas of intense rainfall (darker reds) associated with heavier thunderstorms are located over northeast Texas, western Kentucky, and eastern Tennessee. Rain rates in the center of the swath are from the TRMM Precipitation Radar, while those in the outer swath are from the TRMM Microwave Imager. The rain rates are overlaid on infrared data from the TRMM Visible Infrared Scanner.
TRMM is a joint mission between NASA and the Japanese space agency, JAXA.