Extreme Precipitation Event of Winter Over the Zagros Mountains in Western Iran

Winter precipitation in western Iran is the source of groundwater resources in the region. From this point of view, the study of Extreme winter precipitations in western Iran is very importance. in January, with the spread of western winds, all stations are under the influence of rainfall systems , thus In in this study, extreme precipitation of January have been analyzed in western . According to pervasiveness precipitation criterion in the region level, 10 items of the four-day precipitation periods of January with precipitation maximum from 1996 to 2017 by statistic processing. Finally, from these cases, the four-day period of 3 to 6 January 1996 with most intensity was selected for in this study. The results indicated that the maximum of precipitation has observed in the south, and inland aspects of the zagros. precipitation has been decreasing from south to north of the region. The influence of the Mediterranean system on the bed of a deep trough and its accompaniment with the special humidity stream from the side of warm seas of low Geographic latitudes has provided conditions for the maximum precipitation event in the region.