THE MOISTURE CONTENT AS A FACTOR OF FORMATION OF VERY HEAVY SNOWFALLS IN PERM REGION
In this paper the authors consider the total moisture content in the atmosphere during the formation of very heavy snowfalls in Perm region for the period 1979-2013. Assessment of spatial and temporal variability of the moisture content was conducted with due account for circulation conditions and relief. Data on the total atmospheric moisture content PWAT (precipitable water, kg/m <sup>2</sup>) were obtained from the archive of the reanalysis of CFS models and CFSv2 (Climate Forecasting System). It is found that in most cases hazardous snowfalls were formed at the moisture content 4.0-7.9 kg/m <sup>2</sup>. The seasonal variation of the moisture content agrees well with their intensity. Features of spatial distribution of the moisture content were revealed. It is shown that at all developmental stages of cyclones the areas of maximum moisture correspond to their warm sector, minimum - to their rear parts, while the front zone of each cyclone is characterized by the greatest horizontal gradients of the moisture content, especially at the stage of maximum development of the cyclone.