Synoptic processes of winter precipitation in the Upper Indus Basin

Abstract. Precipitation in the Upper Indus Basin is triggered by orographic interaction and forced uplift of a cross-barrier moisture flow. Winter precipitation events are particularly active this region driven an approaching upper-troposphere western disturbance. Here statistical tools used to decompose winter time series into wind contribution. The relationship between each contribution disturbances investigated. We find that related not only intensity but also their thermal structure through baroclinic processes. Particularly, short-lived disturbance lower-altitude flow occurs due shape relief. This explains both high activity area quick decay as they move further east. revealed existence pathway from Red Sea Persian Gulf north Arabian Sea. A strengthens steers it towards Plain, if originates more southern latitude. In cases where north-west, its impact on limited, since advected continental dry air drastically limits output. study offers conceptual framework synoptic well key parameters explain can be investigate meso-scale processes or intra-seasonal inter-annual activity.