UTC Aug 95. Isosurface represents upward vertical velocity greater than 1 m s-1. The evidence suggests that this convergence zone can act as an important and identifiable source of concentrated vorticity and vertical motion for developing convective towers. Physical and conceptual understanding of this interactive process should improve the capability to forecast its impact on similar convective events in the future. Top panel represents initial convection over the mountains.
Middle view depicts linkage between convective updrafts and the mountain-valley solenoid.
Bottom panel illustrates vertical decoupling and horizontal downwind growth of the solenoid. Furthermore, it has been shown that the vertical circulation associated with these orogenic solenoids can remain intact for several hours after the initial breakdown and decoupling phase forces them away from the genesis zone. Thus as the circulation drifts downstream, it can continue to influence convective organization by geostrophically inducing low level cyclonic shear beneath anti-cyclonic shear aloft. Specific investigation of this process in the Desert Southwest is a topic for further study. Low Froude number flow past three-dimensional obstacles.