In terms of severe weather in the Great Barrier Reef, the location primarily experiences cyclones in the summer. 

The Great Barrier Reef Foundation goes into the differences between cyclones, hurricanes and typhoons saying that they are the same weather phenomenon that are named differently based on their location. They explain that these types of storms are "cyclones when they form over the South Pacific and Indian Ocean, and hurricanes when they occur over the North Atlantic, central North Pacific and eastern North Pacific," additionally, "tropical storms that form in the Northwest Pacific are called typhoons"("How do cyclones affect the Great Barrier Reef?"). NASA explains that regardless of what they are called, "all tropical cyclones are alike in that they draw heat from warm water at the ocean's surface to power horizontal, rotating wind"("What is the difference between a typhoon, cyclone, and hurricane?"). In addition to this, "a tropical storm is declared [a cyclone] and given a name when wind speeds consistently reach 63kph"("How do cyclones affect the Great Barrier Reef?").

The Great Barrier Reef's weather is intrinsically tied to its marine resources, of which the primary resource is tourism. 

Since the Great Barrier Reef is in the Southern Hemisphere, not only are its circulation patterns flliped from the Northern Hemisphere, but the seasons are as well. When the Northern Hemisphere is experiencing summer, the Great Barrier reef is experiencing "winter". Since the reef is a tropical climate, visitors are able to swim  and visit the reef year round. 

In terms of the weather on the reef, there are "two distinct seasons; a winter period of warm temperatures and low rainfall, and a summer period of hot, humid temperatures and higher rainfall"("Great Barrier Reef Weather & Climate"). It is important to note that the weather in the Great Barrier Reef is particularly important in relation to the location's marine resources. If there are bad weather conditions, there is a significant decrease in the location's ability to have tourists visit or learn about the reef.