Interpretation
Physically, the omega equation combines the effects of vertical differential of geostrophic absolute vorticity advection (first term on the right-hand side) and three-dimensional Laplacian of thickness thermal advection (second term on the right-hand side) and determines the resulting vertical motion (as expressed by the dependent variable .)
The above equation is used by meteorologists and operational weather forecasters to assess development from synoptic charts. In rather simple terms, positive vorticity advection (or PVA for short) and no thermal advection results in a negative, that is, ascending motion. Similarly, warm advection (or WA for short) also results in a negative corresponding to ascending motion. Negative vorticity advection (NVA) or cold advection (CA) both result in a positive corresponding to descending motion.
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