Weather forecasts and climate projections now drive a multitude of services and applications. However, the skill of predictions on the intermediate timescale from months to a few years ahead, and their use in applications is much more limited. Despite this, there is great potential benefit to society, as many government and private business users assess risk and make plans on this intermediate timescale.
Long range predictability of the tropics has been established for many years, but some studies have suggested that this may not be possible in the mid-latitudes and that predictions are limited to a broad range of plausible impending climate states. Here we show recent seasonal and decadal prediction results from the Met Office Hadley Centre. Unlike climate projections which rely only on boundary forcing, or weather forecasts which rely only on initial conditions, these predictions are made using a high resolution climate model which is both forced with boundary conditions (e.g. greenhouse gases) and initialised with latest observations (in the atmosphere, ocean and land surface). Significant and potentially useful levels of prediction skill are demonstrated for the North Atlantic Oscillation and hence the UK and Europe. We describe some of the mechanisms that provide this predictability, some of the outstanding scientific problems in this area and some of the emerging services that are helping to bridge the gap between weather and climate services.