NEW YORK ( TheStreet) -- It looks like was a very Merry Christmas for retailers, but with the holiday season behind us, and no imminent catalysts left for shoppers to open their wallets, will they continue to spend in the New Year? That's the million-dollar question heading into December same-store sales results on Thursday. The biggest focus for investors will be any meaningful upgrades to fourth-quarter earnings guidance. Meanwhile, severe weather across much of the U.S. toward the end of the month has spooked investors, who are now wondering how much the storms stifled sales. Overall, analysts are looking for a 3.3% increase in December same-store sales year-over-year, according to Thomson Reuters. --Written by Jeanine Poggi in New York. >To contact the writer of this article, click here: Jeanine Poggi. >To follow the writer on Twitter, go to http://twitter.com/jpoggi. >To submit a news tip, send an email to: firstname.lastname@example.org.