Tropical Storm Octave was considered the worst tropical cyclone in the history of Arizona. The origins of Tropical Storm Octave were from a tropical disturbance that formed south of the Gulf of Tehuantepec on September 23, 1983. Steered by a deep layer high over Mexico, the disturbance moved west for four days before becoming a tropical depression on September 27 off the southwest coast of Mexico. Over an area of warm sea surface temperatures, it was able to quickly strengthen to peak winds of 50 mph (85 km/h), through wind shear prevented much further development. By September 30, Octave was accelerating to the northeast, steadily weakening due to cooler waters. That day it weakened to tropical depression status, and on October 2, Octave dissipated.