The western ranges sit close to the Adriatic and take around 2,500 mm of precipitation a year. Storms coming off the Atlantic pick up moisture over the sea; the air inland is cold and dry. Wet storms meeting cold air is what produces deep coverage and light snow.
The season usually runs from December into March, with January and February the most reliable. January is the coldest month, averaging around −5 °C in the mountains. North and northeast aspects hold cold snow longest, which is why the terrain above Deçan works the way it does.
The comparison people who ski here reach for is British Columbia rather than the Alps: less infrastructure, more snow, and almost nobody on it.