Which meteorological phenomenon is characterized by intense rainfall and strong winds?

The phenomenon characterized by intense rainfall and strong winds is a thunderstorm. Thunderstorms are typically associated with cumulonimbus clouds, which are capable of producing heavy rain, lightning, and strong winds. The intensity of the rainfall can lead to flash flooding, while the winds can result in downbursts or straight-line winds, causing significant damage in some cases.

In contrast, the other options describe different weather conditions. A snowstorm involves precipitation in the form of snow, which is not typically associated with strong winds or intense rainfall. A sandstorm is characterized by strong winds lifting and carrying sand particles, usually in arid regions, and does not involve rainfall. Fog is a weather phenomenon that reduces visibility due to tiny water droplets in the air, but it does not include rainfall or strong winds. Thus, thunderstorm is distinctly characterized by both the potential for heavy rainfall and strong winds, making it the correct choice.