Isn't this year supposed to be an 'El Niño' year. Is this significant to the j-2007 anomalies?

Very good point Louise - Wikipedia says that the last 3 El Ninos were 1997-1998, 2002-2003 and 2006-2007. So here's the Jan charts for 1998 and 2003.



The 1998 El Nino was a strong event - and we still have a lot of blue colours in the Arctic and Siberia. You are right to point out small time-scale variablity and Dec 06 - Jan 07 will no doubt turn out to be a blip on the record. I just find it amazing to have such a huge area of the N hemisphere covered by such a large anomaly.