Flash floods are associated with option 2, cyclonic storms. A flash flood is a rapid and extreme flooding caused by heavy rain or a sudden release of water in a short period of time. Cyclonic storms, also known as cyclones or hurricanes, can produce intense rainfall and lead to flash floods. These storms are characterized by strong winds and heavy precipitation. Thunderstorms, the option 1, can also cause local flash floods due to their intense rainfall. However, flash floods are more commonly associated with cyclonic storms, which have a larger scale and can produce widespread flooding. Tsunamis, option 3, are not related to flash floods as they are caused by undersea earthquakes or volcanic eruptions. Tornadoes, option 4, are also unrelated to flash floods as they are swirling columns of air and do not involve heavy rainfall.