THE NATIONAL WEATHER SERVICE
'(<a href="http://www.j-archive.com/media/2008-11-26_J_26.jpg" target="_blank">Kelly and Sarah of the Clue Crew hold a deflated weather balloon; Kelly reads the clue.</a>) <a href="http://www.j-archive.com/media/2008-11-26_J_26a.jpg" target="_blank">Weather balloons</a> are released twice a day at the National Weather Service; they can rise up to 100,000 feet, where a decrease in this will make the 6-foot balloon expand to 20 feet in diameter'
air pressure