A UVV MAX is a region of lifting air in the atmosphere. This lifting is on the large scale. Some example lifting processes are orographic lifting, low level warm air advection, divergence aloft, frontal lifting, and convergence in the lower troposphere. The region with the greatest amount of lifting will be at the bulls eye of the UVV MAX. High UVV makes cloud formation and precipitation formation very likely. Rising air cools and condenses out moisture once it rises enough to reach saturation.
Generally, a UVV of 6 or greater will lead to clouds and precipitation (if air is not initially too dry). For drier air, higher values of UVV will be needed to generate clouds and precipitation.
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