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Flash flooding can occur in both rural and urban environments. In mountainous areas, steep slopes and narrow valleys can funnel water rapidly downhill. In cities, extensive paved surfaces can channel runoff into streets and drainage systems. In either setting, heavy rainfall can transform a familiar landscape into a hazardous environment.
The hidden danger of lightning
Lightning is another major risk associated with thunderstorms. A person does not need to stand beneath the darkest cloud or in the center of the rainfall to be in danger. Lightning can strike outside the area where rain is falling, and storm conditions may change faster than people expect.
The safest response when thunder is audible is to seek shelter inside a substantial enclosed building or a fully enclosed vehicle with a hard roof. Open shelters, isolated trees, beach umbrellas, gazebos, and temporary structures do not provide equivalent protection.