Assessing the Sources of Subseasonal to Seasonal Predictability in the Climate Forecast System Version 2

Low frequency climate modes are a key source of predictability on the subseasonal to seasonal time scales, and such modes may modulate prediction skill of the mid-latitude atmosphere. The 200-hPa geopotential height from the Climate Forecast System Version 2 (CFSv2) reforecasts are used to assess the effects that low frequency climate modes have on the northern hemisphere winter predictability. In addition, the representation of teleconnections between tropics and extratropics in the CFSv2 are evaluated through the analysis of 200-hPa geopotential height, precipitation rate, and sea surface temperature data, with the objective to identify the windows of high predictability and assist in model improvements.