Cold Air Outbreaks are unique weather events which form special clouds. These clouds transition rapidly from being made of liquid water with more, smaller droplets, to being made of ice with fewer, larger crystals. This is important because these cloud transitions are very hard to represent in models, which can make it hard for us to predict long-term arctic temperature changes. We look at 21 years of cold air outbreak events southeast of Greenland in order to better understand these cloud transitions. We have found that the sea surface temperature is very important but not the sole driver of the clouds changing phase from liquid to solid water. We also investigate other possible drivers such as how clean the air is.