LIGHTENING AWARENESS ...THE SCIENCE OF LIGHTNING... LIGHTNING REMAINS A RANDOM...CHAOTIC AND DANGEROUS FACT OF NATURE. LIGHTNING HAS BEEN SEEN IN VOLCANIC ERUPTIONS AS WELL AS EXTREMELY INTENSE FOREST FIRES IN THE WEST...BUT IS MOST OFTEN SEEN IN THUNDERSTORMS. AT ANY GIVEN MOMENT...THERE ARE 2000 THUNDERSTORMS IN PROGRESS ACROSS THE EARTH. THUNDERSTORMS FORM AS A RESULT OF THREE PARAMETERS: MOISTURE...INSTABILITY AND LIFT (SUCH AS FRONTS... SEA BREEZES OR MOUNTAINS) FORCING THE AIR TO RISE. CLOUDS IN A THUNDERSTORM TYPICALLY RISE TO ELEVATIONS BETWEEN 30000 AND 40000 FEET (5 TO 7 MILES) BUT CAN RISE IN UPWARDS OF 60000 FEET (10 MILES). TEMPERATURES HIGHER IN THE ATMOSPHERE ARE MUCH COLDER AND ICE FORMS WITHIN THE STORM CLOUD VARYING IN SIZE FROM ICE CRYSTALS TO HAILSTONES. THESE PARTICLES MOVE WITHIN A STORM AND COLLIDE WITH OTHER PARTICLES CAUSING SEPARATION OF ELECTRICAL CHARGES. THE LIGHTER ICE CRYSTALS BECOME POSITIVELY CHARGED AND RISE TO THE TOP OF THE STORM...WHILE THE HEAVIER NEGATIVELY CHARGED ICE PARTICLES AND HAILSTONES DROP TO THE LOWER PARTS OF THE STORM. THIS CREATES AN ENORMOUS ELECTRICAL CHARGE DIFFERENTIAL. ALSO...THE MOVING THUNDERSTORM GATHERS ANOTHER POOL OF POSITIVELY CHARGED PARTICLES ALONG THE GROUND THAT TRAVEL WITH THE STORM. AS THE DIFFERENCES IN CHARGES INCREASE BETWEEN THE GROUND AND THE LOWER CLOUD...POSITIVELY CHARGED PARTICLES BEGIN TO RISE UP TALLER OBJECTS SUCH AS TREES...POWER LINES AND HOMES. HAVE YOU EVER BEEN IN A STORM AND FELT YOUR HAIR STANDING UP? YES... THE PARTICLES CAN MOVE UP ON YOU!!! THAT`S NATURES WARNING THAT YOU ARE AT THE WRONG PLACE AND COULD BECOME A LIGHTNING TARGET. THE NEGATIVE CHARGED AREA OF THE STORM WILL SEND DOWN AN INVISIBLE CHARGE TO THE GROUND CALLED THE "STEPPED LEADER". WHEN IT APPROACHES THE GROUND...IT IS ATTRACTED BY ALL THE POSITIVE CHARGED PARTICLES FORMING A CHANNEL. AT THAT POINT... YOU CAN SEE THE ELECTRICAL TRANSFER FROM THE GROUND TO THE CLOUD WITHIN THIS CHANNEL AS LIGHTNING. HOWEVER...NOT ALL LIGHTNING FORMS IN THE NEGATIVELY CHARGED BASE OF A THUNDERSTORM. SOME LIGHTNING ORIGINATES IN THE POSITIVELY CHARGED UPPER LEVELS OF THE STORM AND IS CALLED POSITIVE LIGHTNING. THIS LIGHTNING IS PARTICULARLY DANGEROUS BECAUSE IT USUALLY TRAVELS AWAY FROM THE RAIN CORE AHEAD OR BEHIND THE STORM AT DISTANCES AS FAR AS 10 TO 15 MILES AWAY FROM THE STORM. THUS...LIGHTNING CAN STRIKE WHERE NO RAIN IS FALLING!!! THUNDER IS THE RESULT OF A LIGHTNING STRIKE AND IS CREATED WHEN LIGHTNING HEATS UP THE AIR AROUND IT...UP TO 50,000 DEGREES AND CAUSES THE AIR TO RAPIDLY EXPAND AND CONTRACT. THE SPEED OF LIGHT IS MUCH FASTER THAN THE SPEED OF SOUND. TO ESTIMATE YOUR DISTANCE FROM A LIGHTNING STRIKE...COUNT THE NUMBER OF SECONDS BETWEEN WITNESSING A LIGHTNING BOLT AND THE SOUND OF THUNDER...THEN DIVIDE BY 5. THE END RESULT WILL BE THE DISTANCE IN MILES YOU ARE FROM THAT PARTICULAR LIGHTNING STROKE. HERE/S A SAFETY TIP USING WHAT YOU/VE JUST LEARNED...THE "30/30 RULE". AT THE BEGIINING OF A STORM...WHEN YOU SEE LIGHTNING... COUNT THE TIME UNTIL YOU HEAR THUNDER. IF THE TIME IS 30 SECONDS OR LESS OR YOU DON/T SEE LIGHTNING BUT HEAR THUNDER...SEEK SAFE SHELTER. ALSO...AT THE END OF THE STORM...WAIT 30 MINUTES OR MORE AFTER HEARING THE LAST THUNDER BEFORE LEAVING THE SHELTER. ...LIGHTNING SAFETY FOR OUTDOORS... LIGHTNING IS THE SECOND DEADLIEST NATURAL DISASTER IN THE UNITED STATES WITH AN AVERAGE OF 73 DEATHS AND HUNDREDS OF INJURIES ANNUALLY. LIGHTNING RELATED INJURIES CAN RESULT IN LIFE-LONG PHYSICAL AND MENTAL DISABILITIES THAT CHANGES AN INDIVIDUALS LIFE AS WELL AS THEIR FAMILIES. MANY LIGHTNING DEATHS AND INJURIES IN THE UNITED STATES OCCUR DURING THE SUMMER MONTHS AND DURING THE AFTERNOON HOURS WHEN BOTH LIGHTNING AND OUTDOOR ACTIVITIES REACH A PEAK. BEING OUTDOORS WHEN THUNDERSTORMS ARE NEARBY INVOLVES RISK AND CERTAIN LOCATIONS ARE WORSE THAN OTHERS. OF THE LIGHTNING CASUALTIES IN THE UNITED STATES...ABOUT 48 PERCENT OCCURRED IN OPEN FIELDS, BALLPARKS, PLAYGROUNDS, ETC.; ANOTHER 23 PERCENT UNDER TREES, 12 PERCENT INVOLVING WATER ACTIVITIES, 6 PERCENT INVOLVED GOLFING AND 7 PERCENT INVOLVED PERSONS DRIVING FARM OR OTHER HEAVY EQUIPMENT. THESE CASUALTIES CAN BE EASILY...QUICKLY AND CHEAPLY AVOIDED BY KNOWING WHAT TO DO IF A THUNDERSTORM APPROACHES. FIRST...IF YOU PLAN ON BEING OUTDOORS...KEEP ABREAST OF THE LATEST FORECASTS FROM YOUR LOCAL NATIONAL WEATHER SERVICE OR MEDIA SOURCES. NO PLACE IS SAFE OUTSIDE DURING A THUNDERSTORM!!! THUS...BE VIGILANT WATCHING THE SKY AND AT FIRST SIGNS OF THREATENING WEATHER LIKE A DARKENING OF THE SKY OR RUMBLES OF THUNDER... MOVE INSIDE A SAFE SHELTER. IF YOU HAVEN/T TAKEN SHELTER AT THE FIRST SIGNS OF THREATENING WEATHER...THEN USE THE "30-30 RULE" AS A LAST RESORT. THE "30-30" RULE IS WHEN YOU SEE LIGHTNING...COUNT THE TIME UNTIL YOU HEAR THUNDER. IF THAT TIME IS 30 SECONDS OR LESS... SEEK PROPER SHELTER. IF YOU DON/T SEE LIGHTNING BUT HEAR THUNDER...USE THAT AS A BACK-UP RULE. ALSO...WAIT 30 MINUTES OR LONGER AFTER THE LAST SOUND OF THUNDER BEFORE GOING BACK OUTSIDE. IF YOU OR YOUR CHILDREN ARE INVOLVED IN ORGANIZED, OUTDOOR ACTIVITIES, MAKE SURE IN ADVANCE THAT OFFICIALS IN CHARGE HAVE AND FOLLOW A LIGHTNING SAFETY PLAN. THIS INCLUDES STOPPING ACTIVITIES EARLY TO ALLOW SUFFICIENT TIME FOR PARTICIPANTS AND SPECTATORS TO SEEK SAFE SHELTER. THE BEST AND PROPER LIGHTNING SHELTER IS A HOUSE...LARGE BUILDING OR SCHOOL...NOT A CARPORT...GARAGE OR COVERED PATIO. IF NO BUILDING IS AVAILABLE...GO INSIDE A HARD-TOPPED ALL-METAL VEHICLE. IF YOU ARE CAUGHT OUTSIDE IN A THUNDERSTORM, YOU SHOULD TRY TO MINIMIZE YOUR RISK OF BEING STRUCK BY LIGHTNING. - AVOID BEING THE TALLEST OBJECT IN THE AREA BY AVOIDING OPEN AREAS OR STANDING UNDER ISOLATED TREES. - IF IN AN OPEN AREA...CROUCH ON THE BALLS OF YOUR FEET KEEPING FAR AWAY FROM TREES. - IF CAUGHT ON A BOAT...CROUCH DOWN IN THE CENTER OF YOUR BOAT AWAY FROM METAL. - AVOID METAL OBJECTS SUCH AS TRACTORS...BICYCLES...MOTORCYCLES... WIRE FENCES...CLOTHES LINES...SHEDS...GOLF CLUBS...ALUMINUM BASEBALL BATS...FISHING RODS...TENNIS RACKETS OR TOOLS. ...LIGHTNING SAFETY FOR INDOORS... ALTHOUGH BEING INSIDE A STURDY STRUCTURE IS THE SAFEST LOCATION DURING A THUNDERSTORM...THERE ARE STILL SOME DANGERS THAT EXIST. LIGHTNING STRIKING A HOUSE OR OTHER STRUCTURE FOLLOWS METAL CONDUCTORS SUCH AS ELECTRICAL WIRING...PLUMBING AND TELEPHONE LINES. IN FACT...PHONE USE AND INCREASINGLY COMPUTER USE ARE THE LEADING CAUSES OF INDOOR LIGHTNING RELATED INJURIES. THEREFORE...EVEN INSIDE A HOME...YOU SHOULD KEEP ABREAST OF THE LATEST FORECASTS PROVIDED BY YOUR LOCAL NATIONAL WEATHER OFFICE OR MEDIA. HERE ARE SOME PERSONAL SAFETY TIPS FOR INSIDE THE HOME: - AVOID CONTACT WITH ELECTRICAL EQUIPMENT OR CORDS. IF YOU PLAN TO UNPLUG YOUR ELECTRICAL EQUIPMENT...DO SO BEFORE THE STORM ARRIVES. - AVOID USING CORDED PHONES. CORDLESS AND CELLULAR PHONES ARE SAFER. - AVOID CONTACT WITH ALL WATER AND PLUMBING. - STAY AWAY FROM WINDOWS...DOORS AND STAY OFF PORCHES. LIGHTNING CAUSES SIGNIFICANT PERSONAL PROPERTY DAMAGE WITH ECONOMIC LOSSES OF NEARLY $5 BILLION A YEAR IN THE UNITED STATES. IN ADDITION TO DIRECT STRIKES ON PROPERTY...LIGHTNING GENERATES ELECTRICAL SURGES THAT CAN DAMAGE ELECTRONIC EQUIPMENT SOME DISTANCE AWAY FROM THE ACTUAL STRIKE. TRY TO UNPLUG ANY APPLIANCES BEFORE A THUNDERSTORM ARRIVES... INCLUDING CABLE OR SATELLITE RECEIVERS. IF YOU PLAN ON BEING AWAY FROM YOUR HOME WHEN THUNDERSTORMS ARE POSSIBLE...BE SURE TO UNPLUG UNNEEDED EQUIPMENT BEFORE YOU LEAVE. ADDITIONAL LIGHTNING INFORMATION CAN BE FOUND ON THE INTERNET AT WWW.LIGHTNINGSAFETY.NOAA.GOV.