Abstract
The low-level jet (LLJ) in the winter half-year originates as a south wind over the high plains of Colorado. Kansas, western Oklahoma and West Texas. After formation, the LLJ spreads horizontally and upstream toward the Gulf of Mexico. The air in the LLJ becomes humid when the entrance to the jet moves to the Gulf. The water vapor in the LLJ originates in the nearby waters of the Gulf and enters Texas within the tropical air mass which has a recent (1–3 days) polar origin. A mature LLJ often has multiple maxima of the wind speed.
