On May 21, 1921, the annual National Balloon Race started. Sine balloons were entered, and the start from Birmingham, Ala., was given the benefit of every sort of aerological advice. The several pilots were probably never before so well informed of the current and expected meteorological conditions. Acting as aide to Mr. Upson, in one of the balloons, the writer had an excellent opportunity to become intimately acquainted with the practical side of aerology in free ballooning. Air currents, true to forecasts, were light in speed throughout the race, and few opportunities for making important observations were afforded. By making utmost use of the winds of the lowest, levels unaffected by surface friction, we gained advantage on the other balloons during the first night, and escaped a series of local storms of convectional origin, which forced most of the balloons to land early the 22d. The stagnation of air at all altitudes during the 22d prevented headway until after sunset, when we set out on a curved course which carried us through Kentucky, West Virginia, and to a landing place in southwest Virginia. Flying the second night was at moderate speed, low altitude above ground, and the landing was forced because no wind could be located that would increase our distance from Birmingham. While it is often the function of aerology to indicate where the highest or best directed winds prevail, in this race it was chiefly a matter of directing the escape from most unfavorable winds. Observations on the height and depth of the sea-level pressure gradient winds, their disruption by convection, and the average tendency of a free balloon to move toward decreasing pressure regions were noted. As all the other balloons were forced to land in central Tennessee by severe local thunderstorms, the victory was conditions.
Andrus C. G.: Meteorological aspects of the International Balloon Race of 1920. Mo. Weather Rev., Jan., 1921, 49: 8–10.