An extratropical window of opportunity for subseasonal prediction of East Asian summer surface air temperature

Abstract Previous studies suggest that boreal summer intraseasonal variations along the subtropical westerly jet (SJ), featuring quasi-biweekly periodicity, frequently modulate downstream subseasonal over East Asia (EA). Based on hindcasts from six dynamical models, this study discovered leading two–three-week prediction skills for surface air temperature (SAT) are significantly higher in with stronger oscillation SJ, which best demonstrated eastern Tibetan Plateau, Southwest Basin, and North China. The reasons enhanced wave its energy dispersion SJ cause more regular periodic of SAT, potentially increase regional predictability. This suggests strengthened signals would enhance predictability regions, could provide a window opportunity achieving better EA SAT.