Flash floods are one of the deadliest and most dangerous storm-related weather hazards in the world. As the word implies, flash floods happen suddenly, leaving little amount of time for warning. They usually happens in-streams, canyons, or dry river beds.
It occurs when water flows into a region faster than it can be absorbed into the soil. It is a sudden local flood characterized by a great volume of water in a short duration. Flash floods happens within minutes or hours, caused by heavy rainfall or a release of water from a dam. They move at a very destructive speed and often occur with very little warning.
Natural disasters are among the world’s most dangerous incidents, as they often occur without warning. Hurricanes, tornadoes, floods, and other weather-related events often amount to billions of dollars in direct property damage, with hurricanes causing the most damage and amounting to an average cost of $20.5 billion per event. Hurricane season can bring strong winds and excessive rain, which can result in flash floods.
A flash flood occurs when water flows into a region faster than it can be absorbed by the soil. It is a sudden local flood characterized by a great volume of water in a short duration. Flash floods can occur within minutes or hours of heavy rainfall or rapid snowmelt, giving little time to react. The Whitestone Flood of April 1938 is one of the most significant flooding incidents in the history of Georgia, where an extreme flash flood killed 13 people.
Since flash floods move at a very destructive speed, we must be aware of the conditions that can lead to them. Recognizing the signs of a flash flood can help protect you and your family, and potentially save lives. Here are the essential warning signs you need to look out for:
- Flash floods typically occur following periods of intense rain, particularly when the ground is already saturated and cannot absorb any additional water.
- Rapid rainfall can quickly overwhelm local drainage systems and natural waterways, leading to sudden and unpredictable flooding. The risk of flash flooding increases in urban areas with lots of concrete and little soil to absorb the water, as well as in areas near rivers or downstream from dams.
- It’s important to always stay alert to changes in weather conditions, especially during periods of heavy rainfall, as this could be the first warning sign of a potential flash flood.
Fast-rising Water Levels
- Flash floods often cause water levels to rise quickly. If you notice water levels rising rapidly in a stream, river, or urban area, this could indicate a flash flood is imminent.
- The water doesn’t necessarily have to rise to dangerous levels where you are; an abrupt change in water levels elsewhere can indicate that a flash flood is on its way toward your location.
- If you notice water levels rising suddenly or water starting to flow rapidly, it’s vital to move to higher ground immediately and stay alert for any flash flood warnings.
Sudden Change in Water Color
- If you notice a sudden change in the color of the water, this could be a sign of a flash flood. Rapidly moving water can stir up sediment, causing the water to turn muddy or murky.
- Unusual noises can often serve as an early warning sign of a flash flood. These noises might include a distant roaring or a rushing sound, similar to a freight train. This is the sound of vast amounts of water moving rapidly.
- If you hear this sound and there’s been heavy rainfall, it’s crucial to seek higher ground immediately. This type of audible warning is especially useful at night when visibility may be limited.
- Always trust your instincts and don’t hesitate to move to safety if you suspect a flash flood is imminent.
Sudden Change in Water Temperature
- A sudden drop in water temperature could be a warning sign of a flash flood. This change occurs because floodwaters often originate from higher elevations where the temperatures are lower.
- When these colder waters rush into a river or stream, they can significantly decrease the water’s temperature. If you’re near a body of water and notice a sudden drop in temperature following heavy rainfall, it may be a sign of potential flash flooding.
- Pay attention to local weather reports and alerts. If a Flash Flood Watch or Flash Flood Warning has been issued for your area, take it seriously and prepare accordingly.
- Remember, awareness and preparedness are your best tools against the sudden threat of flash floods. Stay informed, stay vigilant, and stay safe!
Flood Watch Vs. Warning
Here is the difference between a flood watch and a flood warning as seen on the National Weather Service website.
Flash Flood Warning: Take Action!
- A Flash Flood Warning is declared when there is a high probability of a flash flood happening soon or when it is already occurring.
- If you’re situated in an area susceptible to flooding, your immediate response should be to evacuate to higher ground. Flash floods can develop rapidly, sometimes within minutes or hours, and can occur even in areas that haven’t experienced immediate rainfall.
- Flash Flood Warnings have now been improved to provide more impact-based information, enhancing public response. Learn more from the factsheet.
Flood Warning: Take Action!
- A Flood Warning signifies that a hazardous weather event is impending or is currently taking place. This type of warning is declared when there is imminent or ongoing flooding.
Flood Advisory: Be Aware
- A Flood Advisory is given when a predicted weather event could potentially cause inconvenience. While it doesn’t signify severe enough conditions to warrant a warning, if proper caution is not taken, the resulting situations could potentially pose a threat to lives and properties.
Flood Watch: Be Prepared
- A Flood Watch is declared when the conditions are likely to lead to a specific hazardous weather event. It is issued when conditions are conducive for possible flooding. While it doesn’t mean flooding is inevitable, it signifies that flooding could potentially occur.
After the flood, be careful when returning to your home or property. Flash floods can cause severe damage, leading to unstable structures or hidden hazards like sharp objects or electrical wires. If you experience flooding damage, consider contacting professionals like ServiceMaster of Savannah for water damage restoration in Savannah, GA and nearby areas.