Does bias correction in the forecasted SST improve the extended range prediction skill of active‐break spells of Indian summer monsoon rainfall?

Impact of bias correction of sea surface temperature (SST) forecast on extended range (ER, ∼3–4 weeks) prediction skill is studied using the bias‐corrected forecasted SST from Climate Forecast System version 2 (CFSv2) as the boundary condition for running the Global Forecast System version 2 (GFSv2) model. Potential predictability limit is comparable (∼16 days) for both bias‐corrected GFSv2 (GFSv2bc) and CFSv2. Prediction skills of active and break spells and of low‐frequency monsoon intraseasonal oscillations is higher for GFSv2bc at all lead pentads. Although initially same, predictability error after 14 days grows slightly faster for GFSv2bc compared to CFSv2. Bias correction in SST has minimal impact in short‐to‐medium range, while substantial influence is felt in ER between 12–18 days.