Meteorological history of Hurricane Katrina
Hurricane Katrina was a catastrophic tropical cyclone that had a long and complex meteorological history, spanning a month from August 8, to September 7, 2005. Katrina's origins can be traced to the mid-level remnants of Tropical Depression Ten, a tropical wave, and an upper tropospheric trough.
Source: Wikipedia — Meteorological history of Hurricane Katrina (CC BY-SA 4.0)