What is a Gust Front characterized by?

A gust front is specifically characterized by a surge of cold air that occurs when downdrafts from a thunderstorm reach the ground and spread out in all directions. This cold air can create a noticeable temperature drop that impacts the area downwind of the storm.

Typically, a gust front is felt about 5 to 20 miles away from the thunderstorm itself. As the storm releases its downdrafts, the cooler air mass displaces the warmer air near the surface, causing a sudden and often dramatic change in temperature. This effect can be quite noticeable and is often marked by strong winds and changes in cloud conditions.

In contrast, the other options describe phenomena that do not accurately define a gust front. Rapidly rising warm air typically describes convection associated with storm development rather than the effects resulting from a gust front. High humidity levels are a factor in weather but are not a defining characteristic of gust fronts. Finally, fog formation usually occurs due to moisture and temperature changes near the ground, not specifically linked to the cold air surges associated with gust fronts.