Cirrus cloud spreading from the top of a dying cumulonimbus. Cirrus forms from tropical cyclones, and is commonly seen fanning out from the eyewalls of hurricanes. A large shield of cirrus and cirrostratus typically accompanies the high altitude outflow of hurricanes or typhoons, and these can make the underlying rain bands—and sometimes even the eye—difficult to detect in satellite photographs. Thunderstorms can form dense cirrus at their tops. As the cumulonimbus cloud in a thunderstorm grows vertically, the liquid water droplets freeze when the air temperature reaches the freezing point. The anvil cloud takes its shape because the temperature inversion at the
Normally unmanned installation Normally unmanned installation A Normally Unmanned Installation (NUI) is a type of automated offshore Oil/Gas platform designed to be primarily operated remotely, without the constant presence of personnel. These generally were characterized by their small size, often consisting of just a well bay with a helipad on top. They are often a compromise of providing the convenience of surface wellheads, which are easier to build and maintain, while avoiding the high operating costs of a full production platform. They are generally only used in shallower water, where constructing many small NUIs is a relatively easy and cheap option as compared