What kind of weather often occurs under the influence of cold air from the Arctic Ocean?

② in the figure shows the cold air flow in the Arctic Ocean, which often leads to snowstorm. ③ indicates the warm and humid air current in the Gulf of Mexico, which often leads to high temperature weather. Supplementary note ① indicates that the warm and humid air flow from the Pacific Ocean is blocked by tall mountains, and it cannot penetrate into inland areas ④ indicates the dry and cold air flow from the north on the east coast of North America in winter.