Areas of high CAPE in the beta-skirt outside these regions are the subject of an “axisymmetrization hypothesis” explaining how secondary examples of these regions are formed. Microwave satellites are used to see through the CDO that obscures these regions. Mesovortices are found in structures outside these regions that undergo a namesake “replacement cycle.” (15[2])Systems in which these regions are large are assigned high numbers by the (*) Dvorak technique. Because these regions are wider at greater altitudes, their appearance is often compared to a stadium. These regions are surrounded by strong updrafts that rotate about them. A “wall” surrounding these regions (10[1])contains the most intense winds of systems categorized by the Saffir-Simpson scale. For 10 points, name these regions of calm weather at the center of tropical cyclones. ■END■