Weather balloons
test for the likelihood of cloud formations.
If you are like most people, checking the weather is a daily routine. Will you have clear skies for your garden party? Could your tomato plants freeze tonight? Should you wear shorts or a sweater? Weather balloons are put to work every day to answer these questions by ascending into the atmosphere and testing the forces of nature that determine the weather.
Weather balloons test for the likelihood of cloud formations.
Weather Balloons
Weather balloons are filled with lighter-than-air gasses that allow them to rise up to 20 miles into the sky and drift up to 180 miles, gathering information about temperature, humidity, air pressure and wind speed and direction. The latex or neoprene weather balloon itself is the vehicle for the radiosonde. Data collected by sensors on the radiosonde are tracked by radar on the ground and stored for examination by meteorologists.
Twice a day, from 100 locations across the United States, the National Weather Service releases these data-collecting balloons to get a picture of current and developing weather conditions. After approximately two hours, the weather balloon bursts; the radiosonde, about the size of a soda can, floats to Earth on a tiny orange parachute. The radiosonde has a prepaid mailer bag attached so it can be returned to the National Weather Service if found. Of the 73,000 radiosondes launched each year, fewer than 15,000 are recovered.
Temperature
One test performed by weather balloons, launched from 900 locations around the world, tracks changes in temperature. According to the National Weather Service, radiosonde sensors are exposed to temperatures as low as minus 130 degrees Fahrenheit as the weather balloon ascends to the upper atmosphere. Knowing the trends in temperature across the country and the world helps meteorologists predict the weather days, even weeks, in advance.
Humidity
Weather balloons, about 6 feet in diameter when launched, track humidity with sensors on the radiosonde suspended 80 feet beneath the balloon by a strong string. The sensors pick up information on how much water vapor is in the surrounding air. These measurements assist meteorologists in determining relative humidity and dew point. When the air becomes super-saturated with water, the vapor will turn to liquid. Having information from weather balloons can point to locations where rain is likely to fall and at what temperature dew is likely to form.
Atmospheric Pressure
Atmospheric pressure, also known as barometric pressure, is probably the best determinant of clear or cloudy weather. When air pressure is high, clouds are less likely to form and rain is even less likely. The lower the air pressure drops, the more probable clouds will form and rain, snow, sleet or hail could fall if enough moisture is present. Weather balloons track the air pressure as they drift along and report the information back to the National Weather Service for analysis.
Wind
Weather balloons also track wind speed and direction. Knowing if winds are coming toward you and at what speed can help predict thunderstorms, hurricanes, tornadoes and cyclones or just let you know you will have a light breeze for your picnic. In 1806, a British naval commander created the Beaufort scale to measure wind speed. The scale ranges from 0 (calm with winds of less than 1 mile per hour) to 12 (hurricane winds at more than 82 mph). Although it won't be as accurate as a weather balloon, you can measure wind direction yourself with a windsock or weather vane.
