Synoptic Analysis of Sweeping Cold Waves of Iran Case: Chahar Mahal & Bakhtiari, 21 Dec 2004-18 Feb 2005

Human life has been affected by the weather conditions. Since weather conditions may be favorable or adverse, human has tried to defend himself against climatic conditions through understanding the nature of the climate. These efforts led to the identification of the origin and how they were created. Such knowledge is also more accurate and more scientific.In synoptic climatology, by relying on the accepted principle of explanation and analysis of environmental changes of the earth surface through the changes of pressure patterns, it is possible to more explain, analyze, and forecast the climatic phenomena of the earth surface.One of the most important climatic disasters that threaten our country, are cold wave and sever freezing that in some years covers large areas of the country. Freezing usually occurs with the entry of the air masses of below zero degrees. These air masses accompanied with relatively stable and multi-day cold waves that may lead to adverse effects. For example, scarce and extreme cold of January and February 2005 in Iran, which has covered a wide and extensive part of the country. For synoptic explanation and analyze of the sweeping cold wave of Iran, minimum temperature of the stations within the province of Chaharmahal & Bakhtiari was selected and then the data of sea level pressure (SLP) & geo-potential height of middle level of atmosphere was select for explaining this event.