Res 2006-163 - Laserfiche WebLink

Home Browse Search

~~ f:.,., n 11 t I atmosphere; sufficient moisture to form clouds and rain; and upward lift of air currents caused by colliding cold and warm weather fronts, sea breezes or mountains. Lighting is generated by the buildup of charged ions in a thundercloud, and the discharge of a lightning bolt interacts with the best conducting object or surface on the ground. The air channel of a lightning strike reaches temperatures higher than 50, 000 degrees Fahrenheit. The rapid heating and cooling of the air near the channel causes a shock wave, which produces thunder. Lightning damage can result in electrocution of humans and animals; vaporization of materials along the path of the strike; fire caused by the high temperature produced by the strike and a sudden power surge that can damage electrical and electronic equipment. Millions of dollars of direct and indirect damages result from lightning strikes on electric utility substations and distribution lines. While property damage is the major hazard associated with lightning, it should be noted that lightning strikes kill nearly 100 people each year. Richard Kithil, President and CEO of the National Lightning Safety Institute, says that "accurate information [about lightning-induced damage] is elusive" but that "on-going research suggests realistic lightning costs and losses may reach $4-5 billion per year" due to lightning's role in forest fires, structure fires, hazardous materials storage incidents, aircraft-related in-flight mishaps, airline delays, power outages, and electrical infrastructure malfunctions. I The Hays County Mitigation Planning Committee classified: . Hail as "minor" in severity and "likely" in frequency; . Lightning strike as "minor" in severity and" highly likely" in frequency . Thunderstorm as "minor" in severity and" likely" in frequency These hazards are also associated with tornados and high wind hazards. Thunderstorms are a frequent occurrence in Hays County and the Hill Country of Central Texas. They may occur year round; however, the peak season is in the spring of each year. They occur most often between the hours of noon and 10:00 PM. Thunderstorms may be associated with lightning, hail, tornado, and flash flooding conditions. These storms are also capable of producing straight-line winds and microburst with extreme power. Thunderstorms kill more people in the United States than any other phenomenon. The heavy rains associated with thunderstorms often cause flash flooding. Due to the steep terrain, flash flooding is a major hazard and flood related deaths are frequent occurrences in Central Texas. There are numerous low water crossings in Hays County, and the Hays County Mitigation Planning Committee identified a Mitigation Plan Action Item to identify and adequately mark these areas. Flash flooding events can cause waters to rise to the point of impacting businesses and residences. In the aftermath of thunderstorm activity, it is not uncommon to find floodwaters in businesses and homes. I Lightning is a secondary effect of electrification within a thunderstorm cloud system. Lightning damage results from four effects of the lightning strike: electrocution of humans and animals; vaporization of materials along the path of the strike; fire caused by the high Ha~'s count~', Texas Mitigation Plan 82