What are common warning signs that indicate a flash flood might occur?

Listening for thunder and watching for rising water are important indicators of an impending flash flood. Thunder can signal the presence of a storm system that might be generating heavy rainfall upstream, which increases the risk of flash flooding in downstream areas. The sound of thunder often precedes intense thunderstorms, which can produce sudden and excessive rainfall.

Watching for rising water is crucial, as this is a direct indication that water levels are increasing, which is a primary sign of flash flooding. When water levels start to rise rapidly, it means that nearby rivers, creeks, or other bodies of water are becoming dangerously high, and that swift action may be required to ensure safety.

In contrast, clear skies and calm winds are not signs of potential flooding and can be misleading, as storms can develop rapidly without warning. A sudden drop in temperature can occur for various meteorological reasons, but it is not a reliable indicator of flooding. While seeing dark clouds and lightning can hint at a storm's approach, it does not provide specific information about rising water levels or imminent flash floods, making it less meaningful in this context.