Possessing a low-pressure center and wind speeds of at least 74 miles per hour, for 10 points, name these spiral arrangements of rainstorms, examples of which were named Sandy, Andrew, and Katrina.
Two of these entities can interact and merge in the Fujiwhara effect. Some of these entities with maximum potential intensity above an upper bound, denoted v-sub-p, weaken because they lose more energy to friction than they gain from evaporation. Mild forms of these phenomena are called tropical depressions. These phenomena are categorized according to their wind speeds from 1 through 5 on the Saffir-Simpson scale, and the "eye" of one of these is its calmest area. Possessing a low-pressure center and wind speeds of at least 74 miles per hour, for 10 points, name these spiral arrangements of rainstorms, examples of which were named Sandy, Andrew, and Katrina.
Two of these entities can interact and merge in the Fujiwhara effect.
hurricanes [or typhoons; or cyclones; prompt on "tropical storms"]