Welcome to Tropical Dynamics at NCSU

This is a montage of the precursor to tropical cyclone Earl (1998), shown roughly every two days as it marches across the Atlantic from the coast of North Africa to the Gulf of Mexico. The iso-surface of Potential Vorticity (=.4 PVU) is shown in the shaded colors. The precursor to Earl appears as a nearly upright vortex tower and was associated with an easterly wave that originated over North Africa. It eventually reached the Gulf of Mexico, where tropical storm Earl formed on 28 Aug, 1998.