Ali Akbar Rasouli - Tabriz University, GIs & RS Center

Thunderstorm rainfall is considered as a very vital climatic factor because of its significant effects and often disastrous consequences upon people and the natural environment in the northwest of Iran. Some previous studies have indicated that thunderstorm activity is a characteristic feature of the humid / wann spring and summer months in this region and that -all from thunderstorms is a major source of moisture for most parts of the study area. Hoivever, flash floods are usually associated with the type of thunderstorm that produces &alized, but very intense rainfall, which damages property and even results in a loss of life. Consequently, the main purpose of this study was to analyze the spatial variation of rainfalls h b e region, observed during certain large thunderstorm events on 17th and 29th May 2004. kordingly, to distinguish the details of major thunderstorms rainfall distributions, a few TR!LM~ satellites images, have been evaluated. The final conclusion reveals the interplay of synoptic weather situations and physiographic effects in the contrplling of spatial variation of Occasionally , such events could introduce numerous heavy rainfalls in the region and as a result severe damages often arisen frorn flash floods.

Thunderstorm Rainfalls, Northwest of Iran, TRMM Satellites Images, Spatial Variation and Flash Floods