Also shown are winter storm tracks. Precipitation declines inland because of the increased altitude and distance from the sea. Most snow fall occurs in winter when the westerlies are strongest and the storm systems can reach inland farther and more often. When warm moist air does make it all the way to the Polar Plateau , the air cools. Eventually it becomes supersaturated with ice crystals .
Cold air holds less moisture than temperate air.
This means that the air in Antarctica is very dry.