The site displays verification statistics for global NWP forecasts. All data used are on the GRIB G2 (2.5x2.5 degree) grid.
The regions referred to are:
G2 (GLB): Globe
PNA: Pacific North America, 180E-320E, 20N-75N
N60: 60N-90N S60: 60S-90S NPO: N.Pacific SPO: S. Pacific NAO: N. Atlantic SAO: S. Atlantic CAM: Central America NSA: N. South America
Pattern correlations for all NWP models are computed using anomalies respective to a 30-year (1959-1988) climatology of the NCEP/NCAR reanalysis.
Please see this presentation for definitions of the various verification metrics.