Predictable Pattern of Precipitation Over Asian Summer Monsoon Regions

Abstract

AbstractPrecipitation prediction has been a challenging issue. The predictable pattern of Asian summer monsoon (ASM) precipitation is identified by the average predictable time method and precipitation hindcasts from the European Centre For Medium Range Weather Forecasts. The leading predictable pattern is characterized by a dipole pattern with the first center spanning from the northeast Bay of Bengal eastward to the western North Pacific, and the opposite center mainly in the Maritime Continent. It provides skillful prediction up to 21–24 days, far exceeding the skill averaged over the ASM (less than 5 days). Empirical mode decomposition analysis shows that the intraseasonal component, contributing 55% of the total variance of predictable components, provides the most predictability for ASM precipitation. The intraseasonal component originates from the boreal summer intraseasonal oscillation, which is enhanced by local ocean‐atmosphere interactions. The interannual component originating from the El Niño‐Southern Oscillation strengthens the predictability.