NOUS42 KCHS 051423 PNSCHS GAZ087-088-099>101-114>119-137>141-061100- PUBLIC INFORMATION STATEMENT NATIONAL WEATHER SERVICE CHARLESTON SC 923 AM EST TUE FEB 5 2013 ...GEORGIA SEVERE WEATHER AWARENESS WEEK CONTINUES THROUGH FRIDAY... TODAY WE WILL DISCUSS DANGEROUS CONDITIONS PRODUCED BY SEVERE THUNDERSTORMS. WHEN CONDITIONS WILL SUPPORT THE DEVELOPMENT OF MULTIPLE SEVERE THUNDERSTORMS...THE NATIONAL WEATHER SERVICE WILL ISSUE A SEVERE THUNDERSTORM WATCH. A WATCH IS TYPICALLY ISSUED FOR A LARGE AREA WHICH INCLUDES MULTIPLE COUNTIES...SOMETIMES ACROSS MULTIPLE STATES...FOR A PERIOD OF SEVERAL HOURS. WHEN DAMAGING WINDS AND/OR LARGE HAIL ARE IMMINENT OR OCCURRING... THE NATIONAL WEATHER SERVICE WILL ISSUE A SEVERE THUNDERSTORM WARNING. WARNINGS VARY IN SIZE AND DURATION BUT ARE USUALLY IN EFFECT FOR UP TO ONE HOUR. WHEN A WARNING IS ISSUED FOR YOUR LOCATION...YOU NEED TO TAKE IMMEDIATE ACTION TO AVOID INJURY OR EVEN SAVE YOUR LIFE. REMEMBER...WARNINGS CAN BE ISSUED EVEN WHEN NO WATCH IS IN EFFECT. DAMAGING STRAIGHT-LINE WINDS OCCUR MUCH MORE FREQUENTLY THAN TORNADOES AND INDEED PRODUCE MOST THUNDERSTORM WIND DAMAGE. THESE THUNDERSTORM WINDS CAN EXCEED 100 MPH IN EXTREME CASES AND CAN PRODUCE DAMAGE EQUIVALENT TO THAT OF A STRONG TORNADO. STRAIGHT-LINE WINDS OCCUR WHEN COLD AIR RAPIDLY DESCENDS FROM A THUNDERSTORM. TWO TYPES OF STRAIGHT-LINE WIND EVENTS...DOWNBURSTS AND MICROBURSTS...TYPICALLY IMPACT LIMITED AREAS. HOWEVER...THESE PHENOMENA REPRESENT AN EXTREME DANGER TO AVIATION...OFTEN PRODUCE SIGNIFICANT DAMAGE AND CAN PRODUCE FATALITIES AND INJURIES. ANOTHER DANGER ASSOCIATED WITH SEVERE THUNDERSTORMS IS LARGE HAIL. SEVERE THUNDERSTORMS PRODUCE HAIL THE SIZE OF QUARTERS OR LARGER. WITHIN A THUNDERSTORM...STRONG RISING CURRENTS OF AIR CALLED UPDRAFTS CARRY WATER DROPLETS TO GREAT HEIGHTS WHERE FREEZING OCCURS. THE RESULTING HAIL GROWS IN SIZE UNTIL IT BECOMES TOO HEAVY TO BE SUPPORTED BY THE UPDRAFT...THEN IT FALLS TOWARD THE GROUND. MOST HAIL WILL MELT BEFORE REACHING THE GROUND. HOWEVER... THE LARGEST HAILSTONES CAN FALL AT SPEEDS FASTER THAN 100 MPH... MINIMIZING MELTING AND ALLOWING LARGE DAMAGING HAILSTONES TO REACH THE SURFACE. LARGE HAIL CAUSES OVER A BILLION DOLLARS WORTH OF PROPERTY AND CROP DAMAGE EACH YEAR. HAIL THE SIZE OF GOLF BALLS OR LARGER OFTEN OCCURS JUST BEFORE A TORNADO DEVELOPS OR IN THE VICINITY OF A TORNADO. CHECK OUT ADDITIONAL SEVERE WEATHER AWARENESS WEEK INFORMATION ON OUR WEB PAGE AT WWW/ERH.NOAA.GOV/CHS/...AS WELL ON FACEBOOK AT WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHARLESTONSC.GOV. YOU CAN ALSO FOLLOW @NWSCHARLESTONSC ON TWITTER. TOMORROW WE WILL EXAMINE THE DANGERS OF TORNADOES. $$