 Water temperatures must be extremely high (near or above 30 °C, 86 °F), and water of this temperature must be sufficiently deep such that waves do not up well cooler waters to the surface.Wind shear must be low; when wind shear is high, the convection and circulation in the cyclone will be disrupted.Usually, an anticyclone in the upper layers of the troposphere above the storm must be present as well—for extremely low surface pressures to develop, air must be rising very rapidly in the eyewall of the storm, and an upper-level anticyclone helps channel this air away from the cyclone efficiently.