A slow moving upper level low brought widespread rain to the region over the weekend, first in the Lake Cumberland region on Friday night and then gradually spreading northeast. Measurable rain did not reach locations closer to the West Virginia border until Saturday night or Sunday morning. Initial downslope flow coupled with strong high pressure over the Great Lakes region reinforced the drier air in the lower levels of the atmosphere in locations closer to the West Virginia border and slowed the advancement of the band of rain rotating around the low. The image below contains rainfall for the period of around dawn on Friday May 3, 2013 through Monday May 6, 2013.
72 Hour Rainfall ending around 7 AM EDT on Monday May 6, 2013.