Which of the following is true about the visibility conditions regarding thunderstorms?

The assertion that thunderstorm gust fronts can extend visibility ahead of the storm is accurate because gust fronts often result from the downdrafts of a thunderstorm. As a thunderstorm rain falls and the downdrafts hit the ground, the air spreads out horizontally, sometimes clearing or reducing haze in the vicinity. This can lead to increased visibility, particularly in the area just ahead of the storm, where the gust front has passed. In this scenario, conditions may temporarily improve as the prevailing atmospheric conditions change.

The other options do not accurately reflect visibility conditions in relation to thunderstorms. Thunderstorms indeed can significantly reduce visibility within or directly around the storm due to heavy rain, but they do not prevent all visibility. While flight visibility is often affected during thunderstorms, it is not the case that it is always limited; factors such as distance from the storm or the presence of gust fronts can enhance visibility. Additionally, thunderstorm cores are generally associated with heavy precipitation and turbulent conditions that result in poor visibility, contradicting the idea that they enhance it. Therefore, the correct choice underscores the unique situations regarding visibility that can occur with gust fronts related to thunderstorms.