When a cold air mass is moving in to replace a warm air mass, the boundary is called a cold front. As a cold front approaches, we expect reducing air temperature & pressure, and the wind will typically veer (in the northern hemisphere).
Cold fronts move across the ground relatively quickly and have a steep slope. This forces the warm, unstable air to rise rapidly and cumuliform clouds will develop. If the air continues to rise rapidly, the cumulus and towering cumulus will often develop into cumulonimbus clouds (thunderstorms).
In a cold front you can expect:
A cold front can present many hazards to a pilot, including:
A diversion around the weather may be required.