[WeatherBulletin] Public Information Statement - Issued by NWS Greenville-Spartanburg SC

[weather at volcanohost.com]

Weather Bulletin
NOUS42 KGSP 011030
PNSGSP
NCZ033>037-048>059-062>072-082-SCZ001>014-019-020000-

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE GREENVILLE-SPARTANBURG SC
423 AM EST MON MAR 1 2010

THIS IS SEVERE WEATHER AWARENESS WEEK IN THE CAROLINAS. FAMILIES AND 
INDIVIDUALS...AS WELL AS EMPLOYERS AND OTHER ORGANIZATIONS...ARE 
URGED TO USE THIS INFORMATION...AND OTHER AVAILABLE INFORMATION...TO 
DEVISE THEIR OWN SEVERE WEATHER SAFETY PLANS. IF YOU ALREADY HAVE A 
PLAN IN PLACE...YOU ARE ENCOURAGED TO USE THIS OPPORTUNITY TO REVIEW 
YOUR PROCEDURES AND PERFORM DRILLS AND EXERCISES BASED UPON YOUR 
PLAN. TO SUPPORT THIS EFFORT...THE NATIONAL WEATHER SERVICE...IN 
CONJUNCTION WITH STATE EMERGENCY MANAGEMENT...WILL CONDUCT A TORNADO 
DRILL SOMETIME DURING THE WEEK. ORIGINALLY THE TEST WAS GOING TO BE 
HELD ON TUESDAY...MARCH THE SECOND AT 9:00 AM IN SOUTH 
CAROLINA...AND ON WEDNESDAY MARCH THE THIRD AT 9:30 AM IN NORTH 
CAROLINA. HOWEVER...THE TEST MAY HAVE TO BE DELAYED AS A WINTER 
STORM IS EXPECTED TO AFFECT PARTS OF BOTH STATES ON TUESDAY. 

TODAY WE WILL TAKE A CLOSER LOOK AT SEVERE THUNDERSTORMS AND TWO OF 
THEIR ATTENDANT THREATS...LARGE HAIL AND DAMAGING WIND GUSTS. THE 
NATIONAL WEATHER SERVICE DEFINES SEVERE THUNDERSTORMS AS THOSE THAT 
PRODUCE HAIL THE SIZE OF A QUARTER OR LARGER...AND OR WIND GUSTS OF 
58 MPH OR MORE...AND OR TORNADOES.  

THUNDERSTORMS CONSIST OF TWO MAIN AIR CURRENTS...AN UPDRAFT AND A 
DOWNDRAFT. IN THE MOST SEVERE THUNDERSTORMS...AIR MOVING UPWARD 
THROUGH THE STORM CAN EXCEED SPEEDS OF 100 MPH. HAIL ORIGINATES IN 
THE MIDDLE OF THE THUNDERSTORM AS SMALL PARTICLES OF ICE COLLIDE TO 
FORM A SINGLE STONE. THE STONE GROWS AS IT CONTINUES TO COLLIDE WITH 
OTHER ICE PARTICLES AS IT IS CARRIED AROUND THE THUNDERSTORM BY THE 
UPDRAFT AND DOWNDRAFT. WHEN THE STONE BECOMES TOO HEAVY FOR THE 
UPDRAFT TO SUPPORT IT FALLS TO THE GROUND. THEREFORE ALL THINGS 
BEING EQUAL THE STRONGER THE UPDRAFT IS THE LARGER THE HAIL WILL BE. 
THE PEAK TIME OF YEAR FOR LARGE HAIL IN THIS REGION IS APRIL THROUGH 
JULY...WITH MAY BEING THE MOST ACTIVE MONTH. 

DAMAGING WIND GUSTS FROM THUNDERSTORMS ARE THE MOST COMMON FORM OF 
SEVERE WEATHER IN THE CAROLINAS. IN FACT...THIS PART OF THE COUNTRY 
IS ONE OF THE MOST ACTIVE IN THE COUNTRY IN TERMS OF DAMAGING WIND 
GUSTS. THIS IS ESPECIALLY TRUE IN THE PIEDMONT...WHICH IN A TYPICAL 
YEAR EXPERIENCES AT LEAST ONE DAMAGING THUNDERSTORM WIND EVENT EVERY 
5 TO 8 DAYS. THIS ILLUSTRATES THE NEED FOR CITIZENS IN THIS PART OF 
THE COUNTRY TO TAKE SEVERE WEATHER PREPARATION SERIOUSLY. MOST 
DAMAGING THUNDERSTORM WIND GUSTS OCCUR FROM MAY THROUGH AUGUST... 
WITH A PEAK IN JULY. 

DAMAGING WIND GUSTS ORIGINATE FROM THE DOWNDRAFT OF THUNDERSTORMS. 
THE STRENGTH OF A THUNDERSTORM DOWNDRAFT IS MUCH MORE DIFFICULT TO 
PREDICT THAN THE UPDRAFT. EACH YEAR NUMEROUS THUNDERSTORMS OCCUR 
ACROSS THE REGION THAT PRODUCE LITTLE IN THE WAY OF HAIL BUT CAUSE 
WIND DAMAGE. THEREFORE A DAMAGING GUST IS MORE LIKELY TO OCCUR 
WITHOUT WARNING THAN LARGE HAIL. 

MOST OF THE DAMAGING WIND GUSTS IN THE CAROLINAS ARE AROUND 60 MPH. 
THIS IS STRONG ENOUGH TO SNAP OFF LARGE TREE LIMBS...BLOW DOWN SMALL 
TREES OR UPROOT LARGE TREES THAT HAVE WEAKENED ROOT SYSTEMS. TREES 
FALLING ON HOMES OR VEHICLES CAN CAUSE EXTENSIVE DAMAGE... RESULTING 
IN INJURIES OR EVEN FATALITIES TO PEOPLE INSIDE. IN EXTREME 
CASES...WIND GUSTS FROM THUNDERSTORMS CAN EXCEED 100 MPH. WINDS THIS 
STRONG CAN FLIP VEHICLES...UPROOT OR SNAP OFF ENTIRE STANDS OF LARGE 
TREES...CAUSE ROOF DAMAGE TO WELL-CONSTRUCTED HOMES...AND SEVERELY 
DAMAGE OR DESTROY MANUFACTURED HOMES. IN OTHER WORDS...SEVERE 
THUNDERSTORM WIND GUSTS ARE CAPABLE OF PRODUCING JUST AS MUCH DAMAGE 
AS A WEAK OR EVEN MODERATE TORNADO. SEVERE THUNDERSTORMS CAN ALSO 
PRODUCE TORNADOES WITH LITTLE OR NO WARNING. FOR THESE 
REASONS...SEVERE THUNDERSTORM WARNINGS SHOULD BE TAKEN SERIOUSLY. 
PEAK SEASON FOR DAMAGING THUNDERSTORM WIND GUSTS IS IN THE LATE 
SPRING AND SUMMER...BUT THEY CAN OCCUR AT ANY TIME OF THE YEAR.  

WHEN A SEVERE THUNDERSTORM WARNING IS ISSUED...OR DAMAGING WINDS OR 
LARGE HAIL ARE OBSERVED...THE SAFEST PLACE TO BE IS ON THE LOWEST 
LEVEL OF A WELL-CONSTRUCTED HOME OR BUILDING...AWAY FROM WINDOWS. 
REMEMBER...ONE OF THE GREATEST THREATS FROM DAMAGING WIND GUSTS IS 
THE DANGER POSED BY FALLING TREES. AS A PART OF YOUR PREPARATION FOR 
THE SEVERE WEATHER SEASON...DEAD OR SEVERELY DAMAGED TREES THAT ARE 
IN DANGER OF FALLING ON YOUR HOME SHOULD BE REMOVED. EVEN WIND GUSTS 
OF 40 TO 50 MPH ARE CAPABLE OF BLOWING DOWN DEAD OR DAMAGED TREES. 

FOR MORE INFORMATION ON WEATHER SAFETY VISIT OUR WEBSITE AT  
WEATHER.GOV/GSP. 

$$
LANE




Help us continue to bring you great weather info - DONATE TODAY!  http://www.burkeweather.com/donate.htm