The term 'prevailing conditions' can refer to a variety of different things, but in this context it is referring to the CLIMATE and sledding conditions. The crossword solutions for this term are 'CLIMATE' (7 letters) and 'sledding' (8 letters). CLIMATE refers to the average weather patterns and temperature of a region over a long period of time, while sledding is a winter activity that involves sliding down a hill on a sled. Both of these conditions can have a significant impact on the activities people can do in a certain area.