The NYT's article on retail sales in January was headlined: "Despite Snowstorms, Many Retailers Posted Gains in January." It is important to remember that the comparison is made to January of the previous year. There are always snowstorms in the Northeast and Midwest in January. This is only a factor in the data if the snowstorms were worse than normal. That would not obviously be the case for January of this year.
Btw, it is worth noting that the retail chain store reports are of less value than they had been in prior years because Wal-Mart, which accounts for more than half of chain store sales, no longer reports its sales monthly. Sears, which is the second largest retail chain, also does not publicly report monthly sales.
It seems the Post is also surprised by snow in January.