They normally develop in moisture-laden environments as their parent clouds are in the process of development, and it is theorized that they spin up as they move up the surface boundary from the horizontal shear near the surface, and then stretch upwards to the cloud once the low level shear vortex aligns with a developing cumulus cloud or thunderstorm.

They normally develop in moisture-laden environments with little vertical wind shear along lines of convergence, such as land breezes, lines of frictional convergence from nearby landmasses, or surface troughs.

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