Climate is a general term to express broad patterns. For example, Colorado's climate is sunny with warm summers and cold winters. Weather applies to specific movements of air masses, levels of precipitation, and temperature fluctuations at specific times of the year. The Continental Divide runs northwest to southeast through the center of the park atop the high peaks. This accounts for two distinct climate patterns - one typical of the east side near Estes Park and the other associated with the Grand Lake area on the park's west side. In recent years, park researchers have been tracking changes to the climate in the park. Winter (December - March) Lower elevations on the east slope of Rocky Mountain National Park are usually free of deep snow. At higher elevations, arctic conditions prevail. Sudden blizzards, high winds, and deep snowpack are common. The west side of the park experiences more snow, less wind, and clear cold days during these months. Most high country overnight trips require gear suitable for -35 degrees or below. Skiing and snowshoeing conditions are best in January, February, and March.