A vigorous upper level low, a cold front, and a warm front all contibuted to hazardous weather development generally from late on December 9th through December 11th. Thunderstorms developed in the warm sector late Friday evening. This warm sector was rather unstable for December with Lifted Indices -2 to -3 and CAPE values up to 1000. As the storms traveled northeastward, they encountered a warm front. Three tornadoes touched down as the storms interacted with the front. Additional wind damage reports were received as the cold front and associated storms slowly moved eastward into Central Alabama early Saturday morning. Tornado Watches were in effect for portions of Central Alabama between 800 pm and 800 am December 9th into December 10th.
Atmospheric moisture values were tremendous as precipitable water values were a few standard deviations above normal for December. Heavy rain developed near the cold front as energy from the upper low was ejected northeastward. Most locations received 2 to 5 inches of rainfall from the 9th through the 11th. Areas in the far northwest received maximum values of up to 8 inches. This rainfall produced some flash flooding as well as some river flooding.
As the deepening upper low moved over Central Alabama, dynamic coooling was responsible for a changeover to snow in northwest areas. Parts of Marion, Lamar, Fayette, and Winston Counties experienced some snow. The measurable snow ranged from about 1 to 3 inches with a few areas possibly a tad higher.