The thermodynamic and dynamic processes causing the ice cover formation, growth and dynamics are consid- ered. The significance of studying the dangerous ice phenomena like intensive ice drift, ice pressure and ice ridge formation is shown. The brief description of ice cover evolution model used for the short-range ice forecasts is presented. The multi-year variability of ice cover extent in the Arctic Ocean as a whole and in the Arctic seas in particular is analyzed. The basic principles of dividing the ice conditions into types both in summer and winter are presented. The methods of short-range (up to 5 days) and long-range (up to 30 days) ice forecasts are briefly described. The practical realization of forecasting the type of ice conditions used by the North Sea Route Adminis- tration for providing the permissions for navigation in the NSR area is demonstrated.