From the Boulder Daily Camera (William Callahan):
…in the 60 years or more of my interest in meteorology, I have never heard of the “Arctic Oscillation.” That’s the term NASA is using to explain the weekly backbreaking snowstorms that have visited the Northeastern United States since Christmas.
New York City has just experienced its snowiest January on record, and Britain and France experienced historic snowstorms earlier in the month. Apparently, this oscillation is in a “negative phase” where there is very high pressure over central Canada and Greenland. This has caused the jet stream, which normally flows from west to east, to dip unusually far to the south. Temperatures were 18 degrees above normal at Nome, Alaska, and about as much below normal in New England and over the Great Lakes most of the month.