The Use of the Q-Vector in Operational Meteorology

Evaluation of atmospheric vertical motion is now possible on widely available and inexpensive microcomputers. Using the Q-vector form of the omega equation, formulated by Hoskins et al. 1978 allows a meteorologist to evaluate vertical motion throughout the atmosphere. Case studies are presented, using an enhanced version of the Barnes 1985 computer program. The first case study deals with a severe weather situation that resulted in tornadic activity through eastern Texas. The second case study covers a two day period in which a Mesoscale Convective Complex MICC moved through the central plains states. Results of these case studies show that the Q-vector form of the omega equation is a useful tool for evaluating vertical motion and aids in checking the initialization of the prognostic numerical models. The diagnostic charts, from this program, are available one to two hours before other commonly used charts are produced. Program results are best interpreted on meso and synoptic scales however, the diagnostic results are best used when incorporated with other routinely available charts. A drawback to the program is that nongeostrophic effects such as orographic influences and friction are not included.