Hurricane Hilary was a powerful tropical cyclone that caused significant flooding in southwestern Mexico in late September 2011. Hilary was the eighth named storm, seventh hurricane and fourth Category 4 major hurricane of the 2011 Pacific hurricane season. The cyclone developed from an area of low pressure off the Pacific coast of Central America in mid-September. Organizing quickly, the system became a tropical depression on September 21, after gaining enough organization to be declared as such. While moving towards the west-northwest, the depression continued to gather strength and was subsequently upgraded to a tropical storm just several hours later. On September 21, Hilary was declared as a Category 1 hurricane, while located close to the Mexican coastline, where the storm brought heavy rainfall and flooding. Undergoing rapid intensification, Hilary strengthened into a Category 4 hurricane on September 22, recognized with a distinct eye feature. Beginning to enter cooler Ocean temperatures, Hilary began to weaken by September 25 but briefly restrengthened into a Category 4 the following day. Atmospheric conditions became increasingly unfavorable late on September 26, and the system began to weaken. During the afternoon hours of September 30, Hilary became a remnant low, while located several hundred miles away from any landmasses. Category 4 hurricane: peak winds of 145 mph (125 knots), lowest pressure 942 mb. September 21 – October 3, 2011. Accumulated cyclone energy: 31.2. Wiki link Track: NOAA National Hurricane Center, HURDAT2 best track EP092011 (public domain).