Releasing a Weather Balloon at NWS Gray
2012-09-29 19:32:39.000 – Roger Pushor, Weather Observer/IT Specialist
Inflating a Weather Balloon at NWS Gray
I’m going to break from the tradition of Observers writing about what’s happening at the top of the ‘rock’ pile today and talk about an experience I had during my last off week.
It was Thursday morning and I had gotten up early to a perfect day – The skies were clear, with low winds and the temperature was mild. Before I left for my week off I had made arrangements to pick up some equipment and the National Weather Service office in Gray and also have the opportunity to participate in the 7:00 am Weather Balloon release so off I headed about 6:15 so I could be at the NWS office by a little after 6:30. When I got to the office preparations were already underway – The radiosonde that we’d be attaching to the Weather Balloon was hanging from the ceiling of the office by a string and had already been checked out. The final thing we had to do before heading up the hill to the launch site was to point the antenna in the direction we thought the balloon was going to head for the first few minutes after release and to do this we checked the last METAR for Portland and finally for Mount Washington to give us a good idea what the winds in the upper atmosphere were doing.
After a short walk up the hill past Gray Radar on the left and some nice fields we got to the building where we’d be inflating the balloon and assembling the whole package for release. First we got the balloon inflated with helium than tied the neck off with some heavy string. Next it was time to add a parachute so once the balloon got to an altitude where it would expand and break because of the thinning atmosphere the radiosonde could safely return to earth. Along the East coast many of these radiosondes end up landing in the ocean and are never recovered however if you ever do find one please follow the instructions on the device and return it to NWS for reuse.
The seven o’clock hour was now fast approaching when we could release the balloon – We had a release window from 7:00 am and not a minute earlier until 8:30 am to get the balloon off. Everything was ready – We had the balloon all inflated with its parachute attached and about 75 feet of heavy string to hold the radiosonde at a safe distance below the balloon. Seven o’clock came and it was up-up and away. We watched the balloon for a few minutes than headed back down the hill to the office to track it on the computer systems.
After a short walk back down the hill to the office we got in front of a couple of computer screens and could see all of the tracking and weather data coming in. We were watching for a few key points in the flight, the first being when the balloon reached an altitude where the temperature was at the freezing point of 32 degrees Fahrenheit. The next critical point was when the balloon reached a point in the atmosphere where the Air Pressure was 400 millibars which is roughly twenty-three to twenty-four thousand feet above sea level. Once the balloon reached this point we had the data that was needed for the Weather Models. By this time the balloon was in the upper air and moving away from us at over 100 miles per hour.
This was exciting and as I drove home I had to ask myself if this It Specialist is turning into a Weather Geek.
Roger Pushor, Weather Observer/IT Specialist