Oscillation Teleconnections polar map CDAS NH 500-hPa HT Heights (5 d rm) 14 jul 2015: Analyzed 500-hPa heights and anomalies. Five-day mean, centered on the date indicated in the title, of 500-hPa heights and anomalies from the NCEP Climate Data Assimilation System (CDAS). Contour interval for heights is 120 m, anomalies are indicated by shading. Anomalies are departures from the 1981-2010 daily base period means. (Text after NOAA, Northern Hemisphere 500 hecto Pascals Height Anomalies Animation)Illustrates a massive polar high.