Tornadoes - December 2009
NCDC transitioned to the nClimDiv dataset on Thursday, March 13, 2014. This was coincident with the release of the February 2014 monthly monitoring report. For details on this transition, please visit our public FTP site and our U.S. Climate Divisional Database site.
December 2009 was a fairly active month in terms of preliminary tornado reports, with 52. This makes December 2009 the second busiest December of the decade, behind December 2002, which had 99 tornadoes, and the sixth busiest December since reliable records began in 1950. There were three significant tornado outbreaks for the month occurring on the 2nd, 23rd, and 24th. All tornadoes for the month were confined to the Southeast and Gulf Coast, which is typically expected for this time of year. Louisiana and Texas had the most tornado reports with 20 and 16, respectively. There were no tornado related fatalities reported for December.
The December 2nd outbreak had 7 preliminary tornado reports in Georgia and Florida. A low pressure system moved northward out of the Gulf of Mexico into the Ohio River Valley producing unstable conditions across much of the southeastern United States. There were widespread supercell thunderstorms embedded within a larger squall line that produced the tornadoes.
The outbreaks on December 23rd and 24th were associated with a very large extra-tropical cyclone that crossed the country, producing blizzard conditions from Texas to the Canadian border. The cold front associated with the large system produced squall lines and supercell thunderstorms, resulting in tornadoes across Texas, Louisiana, and Mississippi. For the two–day tornado event, Texas experienced 16 tornadoes, Louisiana 19, and Mississippi 1. There were 4 people injured in a housing sub-division in Acadia Parish, Louisiana.