Adaptive bias correction for subseasonal temperature forecasting in East Asia
Subseasonal (2–6-week) temperature prediction is important for climate-risk management, energy dispatch, and early warning of high-impact weather over East Asia. However, operational dynamical forecast systems often exhibit substantial lead-dependent biases in this region. In this study, we evaluate an adaptive bias correction (ABC) framework for East Asian subseasonal 2-m temperature forecasts based on Climate Forecast System Version 2 and European Centre for Medium-Range Weather Forecasts data, and compare its performance with raw forecasts and conventional debiasing. Results show that ABC consistently reduced forecast errors and improved spatial consistency across lead times, with particularly clear benefits during winter cold-surge conditions and summer high-temperature periods. The improvements arise from the complementary integration of climatological, dynamical, and persistence-based information, which helps address the spatiotemporal heterogeneity of forecast errors. These results suggest that adaptive post-processing offers a practical approach to improving operational subseasonal temperature prediction over East Asia.

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