Turn Around, Don’t Drown:
Flash Flooding and Flood Safety

                                                                                                                                

                                                                                                                                                            

While we work and prepare most for tornadoes, the combination of flash floods and river floods have accounted for 14 deaths and over $115 million in damage over the past decade! These numbers compare very close to the number of tornadoes deaths (15) and tornado damage ($208 million) across Kansas during the same time period. During that time, your National Weather Service issued well over 1,500 warnings for flash flooding alone, alerting the public of the flood threat to life and property.   When these warnings are issued for your area, or the moment you realize that a flash flood is imminent, act quickly to save yourself. YOU MAY ONLY HAVE SECONDS!

 

How can a foot or two of water cost you your life?

Water weighs 62.4 lbs. per cubic foot and typically flows downstream at 6 to 12 miles an hour. When a vehicle stalls in the water, the water's momentum is transferred to the car. For each foot the water rises, 500 lbs. of lateral force are applied to the car.

 

However, the biggest factor is buoyancy. For each foot the water rises up the side of the car, the car displaces 1,500 lbs. of     water. In effect, the car weighs 1,500 lbs. less for each foot the water rises. Thus, two feet of water will carry away most automobiles.

 

How do flash floods occur?

Several factors contribute to flash flooding. The two key elements are rainfall intensity and duration. Intensity is the rate of rainfall, and duration is how long the rain lasts. Topography, soil conditions, and ground cover, also play an important role.

 

Most flash floods are caused by slow-moving thunderstorms or thunderstorms repeatedly moving over the same area.

 

When a Flood or Flash Flood WATCH is issued, be alert to signs of flash flooding and be ready to evacuate on a moment's notice. When a Flash Flood WARNING is issued for your area, or the moment you realize that a flash flood is imminent, act quickly to save yourself.

 
Immediately:  

           Get out of areas subject to flooding. This includes dips, low spots, low water crossings, etc.

           Do not attempt to walk across flowing streams. Water moving swiftly, even water 6 inches deep, can sweep you off your feet.

           If driving, be aware that the road bed may not be intact underestimate flood waters. Remember: Turn Around, Don’t Drown! Go another way. NEVER drive through flooded roads or low water crossings! If your vehicle stalls, leave it immediately and seek higher ground.

           Be cautious at night when flooding is hard to recognize.

           Choose camp sites along waterways with care. Remember that storms that are miles away may bring raging water your way.


Critical NWS Flood Products

During periods of torrential rainfall, listen to NOAA Weather Radio, local media, or cable media such as the Weather Channel for the latest information from the National Weather Service and local emergency officials. Critical flood products include:

 

i    Hydrologic Outlook: This product alerts the public when flood producing rainfall is expected in 36 to 72 hours. During the months of February and March, this product also contains information on the potential for flooding from the spring snow melt.

 

i    Flood Watch: A flood or flash flood watch is issued when conditions are favorable for flooding or flash flooding to develop.

 

i    Flash Flood Warning: A warning is issued when flooding is imminent. Flash floods usually develop within six hours of a heavy rainfall event. 

 

i    Urban/Small Stream Flood Advisory (issued as a Flood Statement): These statements are issued when minor flooding problems are expected, namely in flood prone urban areas or near small streams that may rise quickly out of their banks. Even minor flooding can cause huge problems though, if proper precautions are not taken.

 

i    Flood Warning: These warnings are issued for river floods and in the case of longer periods of rain which result in slower rises in flood waters, or for a prolonged flood event.

                      Know your area's flood risk. For information, call your local National Weather Service office, Red Cross chapter, or local emergency management agency. Also, check your homeowner or renter's insurance as these policies normally do not cover flooding. Contact your insurance agent to find out more about the inexpensive opportunities provided by the National Flood Insurance Program.

 

For more information on flooding check out:

 
Turn Around, Don’t Drown toolkit: http://tadd.weather.gov/
National Flood Safety Awarenesshttp://www.floodsafety.noaa.gov
Free historic flood pictures: www.photolib.noaa.gov/historic/nws
 

                      Also, for more information on enhancing your knowledge of hazardous weather and to better prepare your community, be sure to take the Anticipating Hazardous Weather and Community Risk course at: http://meted.ucar.edu/hazwx/frameset.htm 

 


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