Final answer:
Weather conditions behind a cold front are generally cold and dry with winds from the northwest due to the movement of cooler air and the lifting of warmer, moist air that condenses and precipitates before the front passes.
Step-by-step explanation:
The weather conditions behind a cold front would typically be cold and dry, with winds coming from the northwest. This happens because cold fronts involve the movement of colder air towards areas of warmer air, causing the warm air to be lifted upwards.
As the warm air rises and cools, its moisture condenses into clouds and potentially precipitation. However, once the front has passed, the air is generally cooler and drier. The winds shift to come from the direction the cold air is originating from, which in middle latitudes like much of the United States, is often from the northwest.