Which phenomenon is likely associated with significant temperature changes over a short distance?

The phenomenon associated with significant temperature changes over a short distance is the passage of a cold front. When a cold front moves into an area, it brings in much colder and denser air that replaces the warmer air ahead of it. This abrupt change leads to sharp temperature drops, often occurring within just a few minutes. As the front passes, the temperature can shift dramatically, as well as the weather conditions, leading to the potential for thunderstorms or heavy precipitation.

The other options relate to more gradual or stable atmospheric conditions. Stable air conditions imply minimal vertical movement and typically result in uniform temperature with little variation. Pressure systems in equilibrium signify a lack of significant weather changes, meaning temperatures across the area are likely to remain relatively constant. Extended periods of fog occur under stable conditions where humidity is high, leading to a blanket of fog rather than rapid changes in temperature.