Recent reports of flooding rains in Tennessee and the torrential downpours from Hurricane Ida, and its remnants, brings the topic of flash flooding to IQ Weather.
September is the midpoint of hurricane season in the northern hemisphere.
Of course, hurricanes and tropical storms are very heavy rain producers, and there is always a threat for flash flooding with them. That is because they form over warm ocean water and, as a result, contain massive amounts of water vapor that can turn back into rain. Plus, tropical storm systems move rather slowly, so it takes a while for them to move over any one area. The slow movement increases the potential for rainfall dramatically.
It’s not uncommon for a tropical storm or hurricane to produce 20 to 30 inches of rain over any one location. In 2001, Hurricane Allison produced up to 40 inches of rain!
Water is a non-compressible fluid. It can produce enormous pressure on anything in its path. For example, water...