Article Provided By: Bruce Baker (ATDD Division Director); Photo by © Bennie Boss / Albuquerque International Balloon Fiesta
The Albuquerque International Balloon Fiesta is an annual hot air balloon festival that takes place in Albuquerque, New Mexico, over the course of nine days in early October (Figure 1). The event attracts over 500 hot air balloons and over 800,000 attendees each year, making it the largest balloon festival in the world. The 2019 Fiesta is scheduled from October 5-13. During this time, the NOAA Air Resources Lab, UAS Program Office, National Weather Service, and Aircraft Operations Center UAS Section are partnering to provide forecasts for the balloon pilots using a small UAS.
Albuquerque’s cool October morning temperatures help create what’s known as the Albuquerque Box (Figure 2). The “box” is a set of predictable wind patterns that can be used to navigate the balloons at low altitudes. The winds will be from the south at low altitudes, but at higher altitudes they tend to be from the north. Balloonists use these beneficial winds to navigate in a vertical box, taking off and landing in almost exactly the same spot. Balloon pilots do not have a way to steer their hot air balloons, but they can control where the balloon flies vertically by heating the air in the balloon or letting air out.
Forecasting in Albuquerque during the Balloon Fiesta means focusing on certain weather conditions, beginning with trying to determine if the Albuquerque Box will form each morning of the nine-day event. Forecasters need to look for a temperature inversion with cooler air at the surface and warmer air above, as well as for vertical change in the wind direction with height. Ideally, surface winds will be blowing south and winds aloft will be blowing from the north. The third condition meteorologists are looking for is lower humidity and lower dew points. This will increase the chance that the Albuquerque Box will develop. Forecasters as well as balloon pilots need to keep in mind that this combination does not happen often to create the Albuquerque Box.
The NOAA UAS team (Figure 3) will provide meteorological measurements of temperature, relative humidity, and wind speed and direction from the Earth’s surface to 400 meters above ground level using NOAA’s Meteomatics Meteodrone. Information from these flights will be provided to forecasters every 20 minutes from 5a.m. to 11a.m. each day. The Meteodrone will provide more information more frequently which will improve the timeliness of the forecasts and quickly identify the onset of the elusive Albuquerque Box.
