A slow-moving frontal system was responsible for spreading severe storms and flooding across parts of the Midwest over the weekend. Low pressure over the Central Plains resulted in warm, humid air being drawn up from the Gulf of Mexico, which interacted with strong upper-level winds. There were numerous reports of tornados, hail and wind damage on Friday, September 22, 2006 across southeastern Missouri and the central Mississippi Valley. On Saturday the 23rd, the focus shifted eastward into Tennessee and eastern Kentucky with the primary threat being damaging winds. Overall, a total of 10 people died as a result of the storms, but most of the fatalities were due to flash flooding in Kentucky.

From its low-earth orbit, the Tropical Rainfall Measuring Mission satellite (known as TRMM) uses both passive and active sensors to measure rainfall from space, including the first and only space-borne precipitation radar--the TRMM PR. The TRMM-based, near-real time Multi-satellite Precipitation Analysis (MPA) at the NASA Goddard Space Flight Center monitors rainfall over the global Tropics. MPA rainfall totals are shown here for the period 23-24 September 2006 for the Midwest and surrounding region. Rain amounts exceed 10 inches along the Arkansas- Missouri border and into far western Kentucky (red areas). Five-inch amounts (shown in green) stretch from western Oklahoma and up through the Ohio Valley.

The next two images show instantaneous snapshots of the actual storms as they swept through the Midwest ahead of an advancing cold front that was moving eastward through the Mississippi Valley at the time. The images were taken by TRMM at 18:25 UTC (1:15 pm CDT) on 23 September 2006. The first image shows the horizontal distribution of rain intensity as seen from above by the TRMM satellite. Rain rates in the center of the swath are from the TRMM PR, while those in the outer swath are from the TRMM Microwave Imager (TMI). The rain rates are overlaid on infrared (IR) data from the TRMM Visible Infrared Scanner (VIRS). The image shows a long line of storms (long green area) oriented southwest to northeast moving through the central Mississippi Valley 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.