One of our most critical programs at the National Weather Service in Amarillo is the upper air program. Our office is one of 92 National Weather Service stations and one of over 800 stations in the world that launches weather balloons twice each day. The data collected by the weather balloons are ingested into computer forecast models where equations are run using the data. The end result is a computer model forecast, but the human forecaster ultimately determines whether or not the output is reasonable. Therefore, the vital data collected by the weather balloons allows forecasters to produce a forecast for today and/or several days in advance.
Each station around the world launches the balloons at the same time to provide a snapshot of the three-dimensional state of the atmosphere. At Amarillo, the balloons are launched at 6:00 a.m. and 6:00 p.m. during daylight saving time and 5:00 a.m. and 5:00 p.m. during standard time. Occasionally, special balloon launches may be requested, particularly if severe weather is expected. Another interesting scenario occurs when a hurricane poses a threat to the United States coast. 6-hourly special launches may be needed from select upper air stations in order to allow forecasters at the National Hurricane Center to more accuarately forecast where a tropical cyclone may move. Most recently, in fact, almost two-thirds of the upper air stations in the continental U.S. launched special flights every six hours for two days as Hurricane Irene approached the coast. All of this data was ingested into computer models and allowed forecasters at the NHC to produce precise track forecasts with a high degree of confidence.
This tour will give you a detailed look at how meteorologists at the NWS in Amarillo take upper air observations. If you want to skip all of the images and text, you can watch a short video of an actual balloon launch below!
The tour will begin at the upper air inflation shelter building, which is just a short walk outside of our office. The building has a few different areas, including the white dome at the top of the building that houses a lot of the upper air hardware, the small side room that houses the hydrogen tanks, and the main room where the balloon is inflated.
Inside the white dome at the top of the inflation shelter is where the Telemetry Receiving System (TRS) is housed. This is basically the guts of the upper air system. The dish below collects the signal transmitted by a radiosonde and transmits it to the computer system inside the office for processing. This system is called the Signal Processing System (SPS).
The small room on the right side of the building is adjacent to the main room and is where the hydrogen tanks are stored. We have to take extra precautions to not create any static charges since hydrogen is a flammable gas. Each tank of hydrogen can typically fill up three to four balloons.
The main room is where the balloon is inflated and where the flight train is prepared. There are two automatic garage doors attached to this room that allow us to launch from either side of the building, depending on the wind direction. This may not seem like a big deal, but it is a tremendous advantage when the winds are strong. Another thing to note is that this building has no insulation. Therefore, we must dress for the elements, particularly in the winter! Sometimes a wind-driven snow will even accumulate inside the inflation shelter.
Before we begin with the process, we will gather the supplies needed to take an upper air observation: in the black bag - a latex balloon (notice how small it is at this point), a parachute, a radiosonde, a battery to power the radiosonde, and a battery bag. The prepared radiosonde, parachute, and balloon will eventually be tied together and launched.