SWIRLING WINDS AND CRASHING THUNDER CAN BE FRIGHTENING TO EXPERIENCE BUT, JUST LIKE SO MANY THINGS, UNDERSTANDING MORE CAN MAKE US FEEL LESS AFRAID. SO LET’S CHECK OUT THE SCIENCE BEHIND HOW TORNADOS COME TO BE.
TORNADOES ARE SPINNING COLUMNS OF AIR THAT EXTEND FROM A THUNDERSTORM IN THE SKY DOWN TO THE GROUND. YOU CAN’T SEE AIR, SO WHEN WE CATCH A TORNADO ON VIDEO IT IS BECAUSE THE WIND SWIRLS AROUND CONDENSATION FROM THE CLOUDS OR PICKS UP DEBRIS FROM THE GROUND.
THE MOST COMMON TORNADOS FORM FROM SUPERCELLS. SUPERCELLS, LIKE THIS ONE FROM ILLINOIS, ARE THUNDERSTORMS THAT ARE ROTATING. THEY CAN START TO ROTATE WHEN WINDS AT TWO DIFFERENT LEVELS IN THE SKY EITHER BLOW AT DIFFERENT SPEEDS OR IN DIFFERENT DIRECTIONS, THIS CAN BE CAUSED BY TEMPERATURE DIFFERENCES. WHEN THE TWO WINDS COME INTO CONTACT THEY START TO FORM A SPINNING TUBE OF AIR THAT IS EVENTUALLY TURNED UPRIGHT INTO A TORNADO.
FUNNEL CLOUDS LIKE THIS ONE ARE USUALLY THE FIRST VISIBLE SIGN THAT A TORNADO IS FORMING. WHEN A FUNNEL CLOUD FINALLY TOUCHES DOWN IT CAN BE CALLED A TORNADO. TORNADOES DON’T TOUCH DOWN FOR VERY LONG. IN FACT MOST ARE ONLY ON THE GROUND FOR LESS THAN 10 MINUTES, BUT DEPENDING HOW FAST THE STORM IS MOVING THEY CAN MAKE IT A LONG WAY. TORNADOS AVERAGE A DISTANCE OF THREE AND A HALF MILES.
TORNADOES ARE CATEGORIZED ON THE ENHANCED FUJITA SCALE THAT ACCOUNTS FOR THE SPEED OF A TORNADO’S WINDS AND THE DAMAGE IT LEAVES BEHIND. AT THE BOTTOM OF THE SCALE IS AN EF ZERO TORNADO THAT HAS WIND GUSTS OF BETWEEN 65 AND 85 MILES PER HOUR. IT CAN BREAK TREE BRANCHES OR CAUSE SOME DAMAGE TO THE OUTSIDE OF A HOME. AT THE TOP OF THE CHARTS AN EF FIVE TORNADO CAN HAVE GUST OF OVER 200 MILES PER HOUR. IT CAN PICK UP ENTIRE HOUSES AND CARS AND MOVE THEM 100 YARDS!
SCARY, BUT SCIENTISTS ARE CONSTANTLY STUDYING TORNADOS AND HOW THEY FORM TO BE ABLE TO BETTER PREDICT WHEN THEY WILL TOUCH DOWN AND WHERE THEY WILL HEAD. RIGHT NOW USUALLY THEY CAN GIVE A 13 MINUTE WARNING BUT WITH UPDATES TO TECHNOLOGY AND RADAR THEY ARE EXTENDING THAT TIME EVEN LONGER.
OH AND SOMETHING NEAT FROM THIS WEEK IN THE NEWS – NASA SPOTTED TINY TORNADOES OF SORT ON MARS. THESE DUST DEVILS ARE FORMED BY SWIRLING WINDS ON THE PLANET’S SURFACE, SINCE THEY AREN’T TIED TO A THUNDERSTORM THEY AREN’T ACTUALLY TORNADOES, BUT BOY LOOK AT IT GO!
Instuctional Links
Interactive Website: Curriculumbits, Tornadoes
Website Article: Weather Underground, Prepare for a Supercell
Website Article: Sky Diary, Kidstorm, Facts about Tornadoes | Includes diagrams, charts, video & links
Website Article: American Meteorological Society, All About Careers in Meteorology