Which type of flooding is characterized by rapid onset and can occur with little to no warning?

Flash flooding is characterized by its rapid onset, often occurring within minutes or hours of heavy rainfall or sudden release of water. This type of flooding is particularly dangerous because it can happen with little or no warning, often catching people off guard. Flash floods can result from intense rainfall over a short period, the failure of a dam or levee, or the rapid melting of snow, and they are more likely to occur in urban areas where water can accumulate quickly. The quick rise and fall of water levels in flash floods can lead to significant hazards, making preparedness and immediate response crucial for safety.

In contrast, riverine flooding, coastal flooding, and shallow flooding generally have more gradual onset periods and can often be anticipated based on weather forecasts, river levels, or tidal conditions, providing more time for preparation and evacuation.