This map was generated from "Stage IV" precipitation data, which starts with the doppler radar-estimated precipitation and adjusts it from the hundreds of automated rain gauges across the Tennessee Valley. The actual numbers plotted on the map came from daily cooperative observers and automated stations (the 10am "OSO" statement is available from the main Ivan page). Darker colors denote higher rainfall amounts (the legend is at the top-left corner of the image).

As expected, the heaviest rain fell across northeast Alabama. The highest rainfall amount reported to the National Weather Service in Huntsville was 8.06 inches, at Valley Head in northeastern DeKalb County. Rainfall amounts averaged 3 to 5 inches across the Huntsville area. Unusually high amounts were reported across northwest Alabama as well, as a band of heavy rainfall known as a "feeder band" developed well to the west of the center of circulation. A side note: the unusually low numbers in the mountains over Georgia are thought to be related to the terrain, and the few lighter pixels in north central Jackson County may be due to the fact that the Hytop radar is close by (and radars tend to underestimate amounts so close to the radar tower).

Our thanks to the Iowa Environmental Mesonet at Iowa State University for making this data available to us in an easily-mapped format.