Can a Tornado Form Simply by Abruptly Tilting Horizontal Vorticity at a Gust Front?

摘要

It is tempting to imagine that a tornado could develop if extreme horizontal vorticity (attributable to extreme variations in wind with height) is simply tilted into the vertical by the thunderstorm's gust front. However, theory and computer simulations reveal that this mechanism fails to produce a tornado because of the deceleration that occurs within an air stream that approaches a gust front. In order for air to rise abruptly at the leading edge of the cold outflow, air must decelerate as the gust front is neared.