Thermodynamic and Synoptic analysis of torrential rainin the kermanshah

One of the most important disaster in the west of Iran, Particularly in cold season isflood. The precipitation in the west regions is longer while tropical systems arepredominant. In this research we studied this percipitation which is accompany withconvective instability. one long precipitation period (1994) in the cold season ofkermanshah .Maps:surface, 500 & 300 hpa levels , upper atmosphere of kermanshahzone & skew-T diagrams at (1200UTC) hour were applied for synoptical analysis.Thermodynamical indexes mixing ratio,Potential temperature and instability ofAtmosphere (Si,Ki,CAPE)and pw were studied and It As a result west systems, inthese periods, accompany with a meditteranian low pressure system on the earthsurface and upper atmosphere Trouph and supplied enough moisture have suitablepattern for precipitation that . In this region the wind speed is at maximum which canbe identifical from maps 30 hpa levels. With calculation on torrential rain (average pw56 mm and 35 mm for start- average CAPE 1500 j/kg and 1000 j/kg for start - averageki 24 C° and 28 C° for start - average si -5 C° and -1 C° for start on torrential rain forabove factors we can opine about torrential rain not only in the kermanshah but also inother cases.