Nathaniel C Johnson, Princeton University, Princeton, NJ, United States; NOAA Geophysical Fluid Dynamics Laboratory, Princeton, NJ, United States, Michelle L L'Heureux, NOAA/NWS/NCEP/CPC, College Park, MD, United States, Chueh-Hsin Chang, Ewha Womans University, Climate and Energy Systems Engineering, Seoul, South Korea and Zeng-Zhen Hu, Climate Prediction Center, NCEP/NOAA, College Park, MD, United States