Hurricane Patricia

Hurricane Patricia was the most powerful tropical cyclone on record worldwide in terms of maximum sustained winds. It was also the second-most intense on record worldwide in terms of pressure, with a minimum atmospheric pressure of 872 mbar (hPa; 25.75 inHg), just behind Typhoon Tip's 870 mbar. Originating from a sprawling disturbance near the Gulf of Tehuantepec, south of Mexico, 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 2015 Pacific hurricane season. Exceptionally favorable 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. On October 23, the hurricane achieved its record peak intensity with maximum sustained winds of 215 mph (345 km/h). This made it the most intense tropical cyclone on record in the Western Hemisphere and the strongest globally in terms of one-minute maximum sustained winds.

Late on October 23, dramatic weakening ensued and Patricia made landfall near Cuixmala, Jalisco, with winds of 150 mph (240 km/h). This still made it the strongest landfalling Pacific hurricane on record at the time, until it was surpassed by Hurricane Otis in 2023. Patricia continued to weaken extremely quickly, faster than it had intensified, as it interacted with the mountainous terrain of Mexico. Within 24 hours of moving ashore, Patricia weakened into a tropical depression and dissipated soon thereafter, late on October 24.

The precursor to Patricia produced widespread flooding rains in Central America. Hundreds of thousands of people were directly affected by the storm, mostly in Guatemala. At least six fatalities were attributed to the event: four in El Salvador, one in Guatemala, and one in Nicaragua. Torrential rains extended into southeastern Mexico, with areas of Quintana Roo and Veracruz reporting accumulations in excess of 19.7 in (500 mm). Damage in Chetumal reached MX$1.4 billion (US$85.3 million).

As a tropical cyclone, Patricia's effects in Mexico were tremendous; however, the affected areas were predominantly rural, lessening the number of people directly impacted. Violent winds tore roofs from structures and stripped coastal areas of their vegetation. Preliminary assessments indicated hundreds of homes to be destroyed; seven fatalities were linked to the hurricane directly or indirectly, including one during evacuations. Total damage from Patricia was estimated to be at least $462.8 million (2015 USD); the damage in Mexico alone was estimated to be in excess of MX$5.4 billion (US$325 million), with agriculture and infrastructure comprising the majority of losses. Flooding partially associated with remnant moisture from Patricia inflicted US$52.5 million in damage across Southern Texas.

Meteorological history

On October 11, 2015, an area of disturbed weather traversed Central America and emerged over the eastern Pacific Ocean. The disturbance moved slowly over the next few days, later merging with a tropical wave on October 15. The merger of these systems and the effects of a concurrent Tehuantepec gap wind event spurred the formation of a broad area of low pressure. This feature gradually consolidated and became a tropical depression shortly after 00:00 UTC on October 20; at this time the depression was situated roughly 205 mi (330 km) south-southeast of Salina Cruz, Mexico. A mid-level ridge to the north steered the depression generally west and later pulled it north along an arcing path.

Development was initially slowed by locally cooler sea surface temperatures and dry air, and the depression became Tropical Storm Patricia later that day. Once clear of the unfavorable region, Patricia traversed anomalously warm waters within an environment exceptionally conducive to rapid intensification. Dramatic strengthening began late on October 21 and continued through October 23. Patricia reached hurricane strength shortly after 00:00 UTC on October 22, featuring prominent outflow, well-defined banding features, and a developing eye. Data from hurricane hunters investigating the cyclone indicated Patricia to have reached Category 4 status on the Saffir–Simpson hurricane wind scale by 18:00 UTC.

By the early hours of October 23, a clear northward turn took place followed by acceleration northeast. A solid ring of −130 °F (−90 °C) cloud tops surrounded the hurricane's 12 mi (19 km) wide eye and signaled its intensification into a Category 5 hurricane. In a 24-hour time span, Patricia's maximum sustained winds increased by 120 mph (195 km/h), the fastest such intensification in any hurricane observed by the National Hurricane Center (NHC). The hurricane reached its peak intensity at around 12:00 UTC on October 23, with estimated winds around 215 mph (346 km/h) and a barometric pressure of 872 mbar (hPa; 25.75 inHg); these values are based upon continued intensification after a Hurricane Hunter mission into the storm six hours prior. In the NHC's report on Patricia, it is noted that the hurricane may have surpassed Typhoon Tip as the strongest tropical cyclone ever observed, but lack of direct observations at the time of its peak prevents analysis of such.

Later on October 23, rapid weakening ensued as an eyewall replacement cycle took shape and wind shear increased. In the five hours up until landfall in Mexico, Patricia weakened at an unprecedented rate while still over water. However, upon moving ashore around 23:00 UTC near Cuixmala, Jalisco, it remained a strong Category 4 hurricane, with sustained winds of 150 mph (240 km/h) and an analyzed pressure of 932 mbar (hPa; 27.52 inHg). This made Patricia the most intense landfalling Pacific hurricane on record, until Hurricane Otis surpassed it in October 2023. Once onshore, the high terrain of the Sierra Madre mountains accelerated Patricia's weakening. The low- and mid-level circulations of the tropical cyclone decoupled, with the latter accelerating northeast, and Patricia dissipated on October 24 over central Mexico, less than 18 hours after moving ashore.

Records

Hurricane Patricia set multiple records for maximum strength, rate of intensification, and rate of weakening throughout its relatively short existence. With maximum sustained winds of 215 mph (345 km/h) and a minimum pressure of 872 mbar (hPa; 25.75 inHg), Patricia is the most intense tropical cyclone ever observed in the Western Hemisphere. In terms of central pressure, it is also the second-most intense tropical cyclone ever recorded worldwide, just shy of Typhoon Tip in 1979 which had a minimum pressure of 870 mbar (hPa; 25.69 inHg).

Patricia's one-minute maximum sustained winds ranked as the highest ever reliably observed or estimated in a tropical cyclone, surpassing Typhoon Haiyan of 2013. The magnitude of Patricia's rapid intensification is among the fastest ever observed. In a 24-hour period, 06:00–06:00 UTC October 22–23, its maximum sustained winds increased from 85 mph (140 km/h) to 205 mph (335 km/h), a record increase of 120 mph (195 km/h). During the same period, Patricia's central pressure fell by 95 mbar (hPa; 2.81 inHg). Despite record over-water weakening prior to striking Mexico, Patricia became the most intense Pacific hurricane to make landfall, with a pressure of 932 mbar (hPa; 27.52 inHg), until Otis surpassed this intensity with a pressure of 929 mbar (hPa; 27.43 inHg).

Forecast errors

The rapid intensification of Patricia was well-anticipated but poorly forecast. Meteorologists at the NHC indicated the possibility of such in the system's first advisory as a tropical depression. They noted the only inhibiting factor would be how quickly the storm could organize an inner core. Just before the onset of rapid intensification, the agency was unable to utilize the Statistical Hurricane Intensity Prediction Scheme rapid intensification guidance due to technical errors. This likely contributed to even greater errors in the agency's forecast. Initial forecasts were consistently conservative with intensity and dramatic strengthening was not explicitly shown until rapid intensification was already underway.

Preparations

Before Hurricane Patricia arrived, the Government of Mexico issued multiple watches and warnings for coastal communities. A hurricane watch was first raised at 09:00 UTC on October 21, encompassing areas of Michoacán, Colima, and Jalisco. A tropical storm watch also covered portions of Guerrero. As Patricia intensified, the government issued a hurricane warning for areas between Cabo Corrientes, Jalisco, and Punta San Telmo, Michoacán; a tropical storm warning supplemented this for areas farther north and east. The hurricane warning was extended northward to include areas south of San Blas, Nayarit, on October 23. Once the storm moved inland and the threat of damaging winds diminished, these warnings were gradually discontinued on October 24.