Odd structures in 66 year NCEP daily temperature reanalysis
It looks like a Gibbs oscillation, a basic feature of spectral analysis. In a spectral atmospheric model this means that near high orography artificial surface waves exist which may reflect in different variables. They are usually not considered to affect meteorology, however.

onlinelibrary.wiley.com/doi/10.1029/2010JC006927/full
http://journals.ametsoc.org/doi/abs/10.1175/1520-0442%281994%29007%3C1169%3AROTGOI%3E2.0.CO%3B2



This is from Bacmeister, Julio T. "Weather Prediction Models." Climate Change Modeling Methodology. Springer New York, 2012. 89-114.