LAUSR

AbstractWhile much of India is used to heavy precipitation and frequent low pressure systems during the summer monsoon, toward the northwest and into Pakistan, such events are uncommon. Here, as much as a third of the annual rainfall is delivered sporadically during the winter monsoon by western disturbances. Such events of sparse but heavy precipitation in this region of typically mountainous valleys in the north and desert in the south can be catastrophic, as in the case of the Pakistan floods of July 2010. In this study, extreme precipitation events (EPEs) in a box approximately covering this region (25°–38°N, 65°–78°E) are identified using the APHRODITE gauge-based precipitation product. The role of the large-scale circulation in causing EPEs is investigated: it is found that, during winter, it often coexists with an upper-tropospheric Rossby wave train that has prominent anomalous southerlies over the region of interest. These winter EPEs are also found to be strongly collocated with incident western...