Invest (meteorology)

Invests (also called areas of interest) are designated by three separate forecast centers located in the United States: the National Hurricane Center in Miami, Florida, overseeing the North Atlantic and North Eastern Pacific basins (east of the 140°W meridian); the Central Pacific Hurricane Center in Honolulu, Hawaii, monitoring the North Central Pacific basin (between the International Date Line and the 140°W meridian); and the military Joint Typhoon Warning Center in Pearl Harbor, Hawaii (formerly located in the island of Guam), serving U.S. government interests elsewhere (i.e. the North Western Pacific basin west of the International Date Line).

[2] The Joint Typhoon Warning Center also issues unofficial warnings for U.S. government interests (predominantly military) in the Southern Hemisphere, designating tropical invests with the "S" suffix when they form west of 135°E (this spans the whole South Indian Ocean, including the South-Western Indian Ocean basin and the western half of the Australian-region basin), and the "P" suffix when they form east of 135°E (spans both the eastern half of the Australian region and the South Pacific basin).

The Naval Research Laboratory's Marine Meteorology Division also uses the "Q" suffix to designate invests which form in the South Atlantic Ocean,[3][4] even though it is not recognized as an official tropical cyclone basin by the World Meteorological Organization.

In contrast, TC numbers start each year/season with 01 and run upwards, usually up to 30 in NHC and CPHC-monitored basins.

[6] The hard-coded limit imposed by the Automated Tropical Cyclone Forecasting System is 49.