Non-tornadic winds were recorded to have reached as high as 80 mph (130 km/h) at eight locations on December 31, while hail as large as 2.75 in (7.0 cm) was documented north-northeast of Mansfield, Missouri.

[3] The United States Storm Prediction Center first noted a possible New Year's Eve severe weather event as early as December 25, 2010.

Supercells developed in this area during the night of December 30 and tracked across central Missouri, producing several tornadoes and large hail.

However, the bulk of activity during the outbreak was a result of a long line of supercells that tracked from Oklahoma to Illinois, producing five EF3 tornadoes.

Another tore through eastern sections of Fort Leonard Wood in Missouri, destroying 159 homes and causing US$90 million in damage, making it the costliest tornado of the outbreak.

A separate cluster of storms later developed in Louisiana before tracking into Mississippi, producing several tornadoes across southern and central regions of the state on January 1.

[4] As the anticipated event grew closer, confidence in the forecast slowly increased, though uncertainties in the timing and extent of the tornado outbreak still existed.

However, the SPC indicated that discrete tornadic supercells and more severe thunderstorms could result from atmospheric conditions deviating slightly from the forecast.

[6] In contrast, forecasts were more confident in a widespread outbreak of severe weather for New Year's Eve; the SPC issued a slight risk outlook for much of the Lower Mississippi Valley and the Ozarks as a result.

[10] Late that day, scattered thunderstorms developed over eastern Oklahoma and northern Arkansas, producing significant hail.

[22] Reaching their peak strength over Mississippi, the storms gradually lost their intensity as they tracked eastward late on December 31 and into January 1, 2011.

Four cars were displaced by 20–50 yd (18–46 m) and a nearby home sustained significant roof damage and broken windows; this resulted in an EF2 rating for the tornado within Adair County.

Two people were killed when a mobile home was destroyed, while another person died as he was tending cattle when the barn he occupied collapsed.

The warning covered ten counties in Missouri and Illinois straddling the Mississippi River and included St.

However, the most destructive tornado from the passing squall line touched down at 17:48 UTC east-northeast of Murphy, Missouri in northern Jefferson County.

Initially, the tornado was an EF0 with a path width of 40 yd (37 m) and lifted before touching down again just north of Route 30 near the Jefferson-St. Louis county line.

Minor tree damage occurred as the tornado moved through Fenton Park and tracked over the Meramec River.

[62] Beginning on December 29 and continuing for three days, the storm system associated with the tornado outbreak caused strong winds across the Texas Panhandle and eastern New Mexico.

[22] In Scott County, residents were forced to evacuate out of Forest and Morton due to flash floods that caused $470,000 in damage.