What is the relationship between rainfall amounts and the occurrence of flash floods?

Arab Weather - The total amount of rainfall in a particular area does not always reflect the severity of its impact on the land or the extent of flash flood formation. It depends primarily on the rainfall intensity, i.e., the amount of rain that falls per unit time in a given area, which determines the land's capacity to absorb and naturally manage the water.

Imagine a bottle full of water. If you empty its contents all at once onto the ground, the water will collect very quickly. But if you pour the water gradually and slowly onto the same surface, most of the water will be able to be absorbed and drained. This simple theory helps to understand why a small amount of rain can cause strong floods, while a larger amount of rain falling over many hours or days does not cause the same effect.

For example, 40 mm of rain might fall on an area over two full days without causing any flash floods, because the ground is able to absorb the water gradually. In contrast, just 20 mm of rain falling in half an hour can lead to sudden and devastating flash floods, due to the increased rainfall and the ground's inability to absorb the water quickly.

Therefore, it is always advisable to pay attention to cases of heavy rainfall, including cases of atmospheric instability, especially in low-lying areas and valleys, where the risk of flash floods is increased due to the high speed of rainfall in such cases.

And God knows best.