15jan2018_12z_500mb-Analysis_Z-bal_T_PV_QG Published January 20, 2018 at 1401 × 848 in Current Arctic Outbreak 17 January 2018 Part 3 Fig. 1 Depiction of the height field of the 500 mb pressure surface in tens of meter for 1200 Greenwich mean time, 15 January 2018.