Some of the outstanding features of surface and free-air winds over Oklahoma and east Teaxs are presented in tables and graphs. The data are mainly based on four years' pilot balloon records at three stations: Broken Arrow and Fort Sill, Okla., and Groesbeck, Tex., with a total of 7,075 flights. The paper does not aim at completeness for all phases of the wind even for the region covered; an exhaustive compilation of the data for this and other geographic groups is to be published later by the Aerological Division as Part II of An Aerological Survey of the United States.
Notable features of the winds of this group are: At the surface, largely predominating south winds in summer and alternate north and south winds in winter, with a small percentage of east and west winds in all seasons. In the free air, a clockwise shift, with one exception, into a pronounced westerly drift aloft in all seasons; a north component amounting to more than 50 per cent at 4,000 meters and higher over the whole region in all seasons. The one exception is the summer winds of Texas in which a counterclockwise shift occurs, the wind having a northeasterly drift above 4,000 meters.
Graphs have been drawn to show the mean seasonal direction and velocity at the three stations; the percentage frequency of directions for summer, winter, and the year at four selected levels; the annual march of wind speeds based on monthly averages for the region as a whole; features of the diurnal march and the nocturnal stratification of speeds at low altitudes; and the frequency of high winds at ordinary flying levels.