| Lightning Safety Tips Some thunderstorms can be seen approaching, while others hit without warning. It is important to learn and recognize the danger signs. To be the safest, "Seek safe shelter Indoors immediately!" "Danger signs" Distant lightning and thunder. Dark, towering, or threatening clouds or visible cloud bursts. Severe Thunderstorm Watches and Warnings are issued by the NWS. (A severe thunderstorm watch is when the weather conditions are such that a severe thunderstorm damaging winds 58 miles per hour or more, or hail three-fourths of an inch in diameter or greater is likely to develop.) (A severe thunderstorm warning is issued when a severe thunderstorm has been sighted by watchers or indicated by weather radar.) "When Indoors" Secure outdoor objects such as lawn furniture that could blow away or cause damage or injury. Take light objects inside. Shutter windows securely and brace outside doors. Listen to a battery operated radio or television for the latest storm information Stand clear from windows, doors and electrical appliances. Unplug appliances well before a storm nears - never during. Avoid bathtubs, water faucets, and sinks because metal pipes can transmit electricity. Do not use the telephone except for emergencies. L lightning can follow the electrical and phone lines. When Outdoors: Look for, and get in a hard topped car. Never use a tree as a shelter. Avoid areas that are higher than the surrounding landscape. Keep away from metal objects including bikes, golf carts, fencing, machinery, etc. Avoid tall structures such as towers, tall trees, fences, telephone lines, or power lines. Stay away from natural lightning rods such as golf clubs, tractors, fishing rods, bicycles, or camping equipment. Be aware of the potential for flooding in low-lying areas. Immediately get out and away from pools, lakes, and other bodies of water. Removing all metal objects from your person is recommended. Don't stand in a crowd of people. - "Spread out" If you feel a tingling sensation, your hair stands on end or you hear 'buzzing' from nearby rocks, fences, etc., move immediately. Lightning may be about to strike! Immediately crouch down, get on the balls of your feet and cover your ears. Do not lie down or place your hands on the ground. What to do if you or someone around you is struck by Lightning? If the victim is burned, provide first aid and call 911 immediately. Look for burns where Lightning entered and exited the body. If the strike cause the victim's heart and breathing to stop, give cardiopulmonary resuscitation (CPR) until medical professionals arrive and take over. "Prepare for an emergency" Have disaster supplies on hand Flashlight with extra batteries Portable, battery-operated radio and extra batteries First aid kit and manual Emergency food and water, Nonelectric can opener, Essential medicines, Cash and credit cards. Dead or rotting trees and branches can fall during a severe thunderstorm and cause injury and damage. Teach family members how and when to turn off gas, electricity and water. Teach children how and when to call 9-1-1, police, fire department, and which radio station to tune for emergency information. Develop an emergency communication plan. In case family members are separated from one another during a thunderstorm (a real possibility during the day when adults are at work and children are at school), have a plan for getting back together. Ask an out-of-state relative or friend to serve as the "family contact". After a disaster, it's often easier to call long distance. Make sure everyone knows the name, address, and phone number of the contact person. |
| How is lighting formed? (Part 1) Ice crystals at the top of the cloud accumulate positive charges; rain drops in the bottom half of the cloud consist mostly of negative charges; the ground below the cloud becomes positively charged. The separation in charges within the cloud is produced by rapidly rising air, called updrafts, interacting with precipitation moving downward within the cloud. The stronger the updrafts, the greater the electrical potential developed. Lightning flashes when the attraction between positive and negative charges becomes strong enough to overcome the air's high resistance to electrical flow. The entire process takes less than a second, and this is how it happens. |
| How is lighting formed? (Part 2) The Lightning stroke originates from negatively charged "step leaders" at the base of a thunderstorm cloud. These step leaders surge downward 150 feet at a time, sometimes more horizontally than vertically, attempting to complete a channel to the ground. Electrical charges separate within the cloud; positive charges accumulate at the top of the cloud, negative charges at the base of the cloud. The negatively charged cloud base induces a positive charge at ground level. The negatively charged electrons begin to descend in a zigzagging pattern. This is the "step leader." As the "step leader" nears the ground, it draws a positively charged "streamer" upward. This "streamer" is normally drawn from the tallest nearby object. As the "step leader" and "streamer" connect, a powerful electrical current begins flowing downward. When the step leader is close to the ground, one or more positively charged "streamers" are pulled upward, usually from a tallest item in the vicinity (for example: trees, buildings, flag poles, golfers). The last surge of a step leader completes the electrical channel with the ground and the Lightning stroke becomes visible. The light seen is the return stroke, an intense wave of positive charge that travels upward about 60,000 miles per hour. The process can repeat several times along the same path in less than half a second, making Lightning appear to flicker. |
