Skillful long-range prediction of European and North American winters

Wednesday, 17 December 2014: 9:45 AM
Rosemary Eade1, Adam A Scaife2, Alberto Arribas2, Ed Blockley2, Anca Brookshaw2, Robin T Clark2, Nick Dunstone2, David Fereday2, Christopher Kenneth Folland2, Margaret Gordon2, Leon Hermanson2, Jeff Knight2, Daniel J Lea2, Craig MacLachlan2, Anna Victoria Maidens2, Matthew Martin2, Andrew Peterson2, Doug Smith2, Michael Vellinga2, Emily Wallace2, Jennifer Waters2 and Andrew Williams2, (1)Met Office Hadley center for Climate Change, Exeter, EX1, United Kingdom, (2)Met Office Hadley center for Climate Change, Exeter, United Kingdom
Until recently, long-range forecast systems showed only modest levels of skill in predicting surface winter climate around the Atlantic Basin and associated fluctuations in the North Atlantic Oscillation at seasonal lead times. Here we use a new forecast system to assess seasonal predictability of winter North Atlantic climate. We demonstrate that key aspects of European and North American winter climate and the surface North Atlantic Oscillation are highly predictable months ahead. We demonstrate high levels of prediction skill in retrospective forecasts of the surface North Atlantic Oscillation, winter storminess, near-surface temperature, and wind speed, all of which have high value for planning and adaptation to extreme winter conditions. Analysis of forecast ensembles suggests that while useful levels of seasonal forecast skill have now been achieved, key sources of predictability are still only partially represented and there is further untapped predictability.