Todays weather related topic is floods and flash floods. This is number 5 in the series and I hope you have gotten some useful information from the series that will help keep you safe no matter what Mother Nature has to throw at you. This information is from the National Weather Service.
…Severe Weather Awareness – Floods and Flash Floods…
In addition to lightning, high winds, hail, and tornadoes, summertime thunderstorms also bring the threat of flooding and flash flooding to northern New England. In the summertime, most flash floods are caused by heavy, slowly moving thunderstorms which can produce excessive rainfall in an area in just a short period of time. In addition to the rainfall, topography, soil conditions, and ground cover help determine how much of the rainfall soaks into the ground and how much of the rainfall runs off into streams and rivers.
Last year, on July 2, a flash flood caused by slow-moving thunderstorms which produced 2 to 4 inches of rain in just 3 hours, caused an estimated $10 million in damage in Grafton and Sullivan counties in New Hampshire.
Nationwide, floods and flash floods are the greatest storm-related killer, claiming the lives of about 85 people annually. Similar to the rest of the nation, floods and flash floods are the number one storm-related killer in New England. In addition, floods and flash floods are responsible for a considerable amount of public and private property damage.
Nationally, 66 percent of last year’s flood fatalities were caused by people attempting to drive through flooded areas. Another 19 percent were caused people attempting to run, walk, swim, or just fell into a flooded area. As little as 2 feet of water will float most cars and small trucks. If your vehicle begins to float, you lose complete control over the vehicle. If your vehicle stalls in a flooded roadway, abandon it immediately and seek higher ground. The water may sweep the vehicle and its occupants away.
Dam failures can also lead to floods or flash floods. While not always caused by the weather, dam failures can lead to extremely fast rises in river and stream levels.
To alert the public to the threat of flooding, the National Weather Service issues flood and flash flood watches and warnings. A flood watch indicates flooding/flash flooding is possible, and is usually issued in anticipation of heavy rainfall. A flood/flash flood warning indicates that flooding is imminent or is already occurring. If you hear that a flood/flash flood warning has been issued for your area, move immediately to higher ground if flood waters threaten.
Here are some flood/flash flood facts and safety tips.
* Never drive a car into a flooded roadway. More than half of all flash flood fatalities are vehicle related.
* Keep away from streams during heavy rainfall events. Swiftly moving water is extremely powerful and can easily overpower a person.
* Keep children inside and away from flooded streets, culverts, and streams. * Report any flooding to the appropriate authorities.
* If advised to evacuate, do so immediately.
* Obey all road blocks and barriers, even if the flooding has receded. Flood waters may have undercut the road surface or left dangerous debris in the roadway.
* If you live in a flood prone area, have a plan in case the water starts rising quickly.