A wind shift from the south or southwest to the northwest is commonly associated with the passage of cold front.
Regions where cold air masses are replaced by warm air masses are called cold fronts. Cold fronts generally move from the northwest to the southeast. A cold front leaves the air much colder and drier than the air that preceded it.
Temperatures might drop more than 15 degrees in the first hour after a cold front sweeps through. A solid blue line is used to represent a cold front on coloured weather maps. A cold front often has a considerable temperature difference from one side to the other.
