Hurricane Patricia was the most intense tropical cyclone ever recorded in the Western Hemisphere in terms of barometric pressure, and the strongest globally in terms of reliably measured maximum sustained winds. Originating from a sprawling disturbance near the Gulf of Tehuantepec in mid-October 2015, Patricia was first classified a tropical depression on October 20. Initial development was slow, with only modest strengthening within the first day of its classification. The system later became a tropical storm and was named Patricia, the twenty-fourth named storm of the annual hurricane season. Exceptional environmental conditions fueled explosive intensification on October 22. A well-defined eye developed within an intense central dense overcast and Patricia grew from a tropical storm to a Category 5 hurricane in just 24 hours—a near-record pace. Early on October 23, Hurricane Hunters revealed the storm to have acquired record maximum sustained winds of 200 mph (325 km/h); a subsequent recon mission found a record low pressure of 879 mbar (hPa; 25.96 inHg).