The rapid decay of a low-level Jet during IHOP

Abstract On 3 June 2002, several mesoscale, dynamical mechanisms acted together, resulting in the rapid decay of a low-level jet (LLJ)—as we conclude from an analysis of dropsonde data gathered from a Falcon research aircraft flying over a southerly low-level jet crossing over northwest Oklahoma. In addition to increased drag produced by the growth of the mixed layer in the atmospheric boundary layer (ABL), heating and perhaps vertical motion resulted in a dipole pattern of warming and cooling that extended from northwest to southeast resulting in weakening and reversing of the thermal wind gradient across the LLJ. Dropsonde deployment began at 1104 UTC from the research aircraft, which flew above the jet core along a rectangular flight track oriented so that the longer sides of the rectangle were orthogonal to the LLJ. Data from this flight and from a second mission (