Tornadoes on December 22, 2011

Tornadoes on December 22nd, 2011

Event Summary for Central Alabama

As part of a week's worth of shortwave troughs coming out of the four-corners region of the southwest United States, Central Alabama was brought a piece of coal-like Christmas present in the way of severe weather. On the evening of Wednesday, December 21, this particular shortwave began moving towards the southeast United States. With the upper trough tilting negatively overnight, a surface low developed near New Orleans early in the morning of December 22 in response to this shortwave and trekked northeastward into Central Alabama. Dew points increased 20-25 degrees from the previous day, which greatly increased the surface based instability. This, coupled with the very high wind shear from the passing low, set up the perfect environment for tornadoes to develop. The highest instabilities were in the central and southeast portions of Central Alabama, and these areas were where the tornadoes eventually formed. Fortunately, no one was injured in any of these tornadoes.

Preliminary Public Information Statement

The information below summarizes the tornadoes from this day, with each tornado path linked to its own webpage:

Location/Clickable Detailed Summary Link	Damage Rating/Estimated Maximum Wind Speeds	Injuries/Fatalities	Damage Path Length/Width	Starting Point/Time	Ending Point/Time
Centreville (Bibb County)	EF-0 70-80 mph	None	0.06 miles 25 yards	32.9053/-87.1224 12:56 pm	32.9053/-87.1224 12:57 pm
Lawley (Bibb County)	EF-0 80 mph	None	2.62 miles 150 yards	32.8692/-86.9742 1:25 pm	32.8796/-86.9307 1:28 pm
Dallas County 6 miles E of Selma	EF-0 85 mph	None	2.17 miles 50 yards	32.4232/-86.9206 1:30 pm	32.4305/-86.8844 1:33 pm
Columbiana (Shelby County)	EF-0 70-80 mph	None	1.83 miles 50 yards	33.1828/-86.6070 1:42 pm	33.2027/-86.5860 1:45 pm
Autauga/Elmore Counties	EF-0 85 mph	None	10.18 miles 100 yards	32.6203/-86.5478 2:02 pm	32.7019/-86.4059 2:16 pm
Elmore/Coosa/Tallapoosa Counties	EF-1 90-100 mph	None	24.9 miles 300 yards	32.7438/-86.2996 2:24 pm	32.9902/-85.9920 2:52 pm

Pertinent Geographic Information Systems (GIS) Data from this Event

Severe Weather Episode Data

500 mb Analysis Dec 21 at 6 pm	500 mb Analysis Dec 22 at 6 am
Surface Analysis Dec 22 9 am	Surface Analysis Dec 22 12 pm
Day 2 Severe Weather Outlook Issued Dec 21 at 1130 am	Day 1 Severe Weather Outlook Issued Dec 22 at 7 am
Storm Reports 12/22/11	Upper Air Sounding Dec 22 at 6 am