NOUS42 KILM 061059
PNSILM

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE WILMINGTON NC
600 AM EDT TUE MAR 06 2012

...SEVERE WEATHER AWARENESS WEEK IN NORTH AND SOUTH CAROLINA MARCH 
04 TO MARCH 10...

TODAYS TOPIC WILL BE LIGHTNING SAFETY.

LIGHTNING OCCURS WITH ALL THUNDERSTORMS AND IS WHAT DEFINES A 
THUNDERSTORM. OVER THE COURSE OF ONE YEAR, THE EARTH WILL BE STRUCK 
BY LIGHTNING NEARLY 20 MILLION TIMES. EVERY YEAR AN AVERAGE 58 
PEOPLE ARE KILLED BY LIGHTNING STRIKES WHICH IS MORE THAN THOSE 
KILLED BY TORNADOES. UNFORTUNATELY THIS NUMBER IS LIKELY LOWER THAN 
THE ACTUAL NUMBERS OF LIGHTNING DEATHS PER YEAR. THE CAROLINAS FACE 
DANGERS FROM LIGHTNING THROUGHOUT SPRING AND SUMMER. TO AVOID 
BECOMING A LIGHTNING STATISTIC JUST REMEMBER, WHEN THUNDER ROARS GO 
INDOORS. 

...WHAT CAUSES LIGHTNING AND THUNDER?...
LIGHTNING RESULTS FROM THE BUILDUP AND DISCHARGE OF ELECTRICAL 
ENERGY BETWEEN POSITIVELY AND NEGATIVELY CHARGED ICE PARTICLES 
WITHIN THE STORM CLOUD. A THUNDERSTORM GENERATES A HUGE STATIC 
ELECTRICAL CHARGE AS ICE PARTICLES INSIDE THE STORM COLLIDE AND 
THROUGH FRICTION GENERATE A STATIC CHARGE. THESE PARTICLES OF 
SUSPENDED ICE IN THE THUNDERSTORM COLLIDE AS THEY ARE CARRIED AROUND 
BY THE STORMS UPDRAFT AND DOWNDRAFT. ONCE THE STATIC ELECTRICAL 
CHARGE IS STRONG ENOUGH TO TRAVEL FROM THE CLOUD TO THE GROUND, A 
LIGHTNING BOLT IS CREATED.

A LIGHTNING BOLT CONTAINS AS MUCH CURRENT AS THREE HUNDRED THOUSAND 
AMPERES AND AROUND THREE HUNDRED MILLION VOLTS. THE INTENSE 
ELECTRICAL CURRENT HEATS THE AIR AROUND THE LIGHTNING STRIKE 
INSTANTLY TO 50,000 DEGREES. THIS IS FIVE TIMES HOTTER THAN THE 
SURFACE OF THE SUN. THE INSTANTANEOUS HEATING OF AIR AROUND THE 
LIGHTNING STRIKE CAUSES THE AIR MOLECULES TO EXPLOSIVELY EXPAND. 
THIS EXPANSION OCCURS SO RAPIDLY IT COMPRESSES THE AIR FORMING A 
SHOCK WAVE SIMILAR TO A SONIC BOOM. THE SHOCK WAVE TRAVELS THROUGH 
THE ATMOSPHERE...RESULTING IN THUNDER. THE ACOUSTIC SHOCKWAVE NEAR 
THE LIGHTNING STRIKE IS STRONG ENOUGH TO RUPTURE THE EARDRUMS OF 
THOSE STANDING NEARBY. 

SINCE LIGHT TRAVELS FASTER THAN SOUND, YOU CAN USE THUNDER TO GAGE 
THE DISTANCE OF A LIGHTNING STRIKE. YOU MERELY COUNT THE NUMBER OF 
SECONDS BETWEEN THE MOMENT YOU SEE THE FLASH OF LIGHTNING AND HEAR 
THE CLAP OF THUNDER. ONCE YOU SEE LIGHTNING...START COUNTING 
SECONDS. FOR EVERY 5 SECONDS THAT GO BY BEFORE YOU HEAR THE CLAP OF 
THUNDER...THAT IS ONE MILE. KEEP IN MIND THIS TECHNIQUE ONLY TELLS 
YOU HOW FAR AWAY THAT ONE LIGHTNING STRIKE WAS FROM YOUR LOCATION. 
THE NEXT ONE COULD BE A LOT CLOSER. LIGHTNING CAN TRAVEL 10 TO 12 
MILES FROM A THUNDERSTORM. THIS IS OFTEN FARTHER THAN THE SOUND OF 
THUNDER TRAVELS. THAT MEANS THAT IF YOU CAN HEAR THUNDER YOU ARE 
CLOSE ENOUGH TO A STORM TO BE IN DANGER OF BEING STRUCK BY 
LIGHTNING. WHEN THUNDER ROARS GO INDOORS.

MOST LIGHTNING FATALITIES OCCUR WHEN PEOPLE ARE CAUGHT OUTSIDE 
WORKING, PLAYING, BOATING OR GOLFING. BECAUSE OF THE ABUNDANCE OF 
OUTDOOR ACTIVITIES IN NORTH CAROLINA...WE ARE ESPECIALLY VULNERABLE 
TO LIGHTNING. IF YOU ARE OUTSIDE...MOVE INDOORS AS SOON AS THUNDER 
IS HEARD. IF CAUGHT OUTDOORS, STAY AWAY FROM TREES, TELEPHONE POLES, 
AND OTHER TALL OBJECTS. A VEHICLE WILL OFFER GOOD PROTECTION FROM 
LIGHTNING. WHEN BOATING...TRY TO SEEK SAFE SHELTER WELL BEFORE THE 
STORM APPROACHES. 

WHEN INDOORS, DO NOT USE CORDED TELEPHONES AND STAY AWAY FROM 
WINDOWS. ALSO STAY AWAY FROM PLUMBING AND WATER SOURCES SUCH AS THE 
SINK, TUB OR SHOWER. IN MANY CASES LIGHTNING FINDS ITS WAY INTO YOUR 
HOME THOUGH THE UTILITIES. WHEN SHELTERING FROM LIGHTNING, STAY 
INDOORS FOR AT LEAST 30 MINUTES AFTER HEARING THE LAST CLAP OF 
THUNDER. THIS SHOULD GUARANTEE YOUR SAFETY. 

$$