SAN JUAN, PUERTO RICO, USA
23–26 APRIL 2016
RA IV/HC-38/Doc. 3.2(10)
REVIEW OF THE PAST HURRICANE SEASON
Reports of hurricanes, tropical storms, tropical disturbances and related floodings during 2015 Report by Mexico (Submitted by Mexico) Description of the cyclone season in Mexico The general behaviour of tropical cyclones meant that the 2015 season was regarded as very active for Mexico in terms of intensity, the total number of cyclones and four direct impacts on Mexican coasts.
The tropical cyclone season of 2015 was well above the average in the eastern North Pacific Ocean, where a total of 22 systems were recorded, 18 of which reached the intensity of tropical storms or hurricanes. Between 1949 and 2014 the average formation of tropical storms and hurricanes is 13.3 named cyclones.
In contrast, in the Atlantic Ocean during 2015, there were 12 tropical cyclones, 11 of which reached the intensity of tropical storms or hurricanes. The figure is similar to the average for 1940-2015, of 11.1 named cyclones.
The most notable of the 2015 season was the development of intense Hurricane "Patricia" which reached a maximum intensity of category 5 on the Saffir-Simpson scale and broke the records in the whole historical database of hurricanes formed in the western hemisphere, with a minimum central pressure of 872 millibars, exceeded only by Typhoon Tip in 1979 which had a minimum pressure of 870 millibars.
Summary table of tropical cyclones for the 2015 season
TD 1-E / Andres
TD 1 / Ana
TD 22-E / Sandra
TD 12 / Kate
Patricia 325 km/h
Joaquín 250 km/h
Intense hurricanes (3-4-5)
Strong hurricanes (1-2)
(+) Bill, at the stage of unstable low-pressure zone with potential to develop into a cyclone, directly affected Quintana Roo.
A total of four tropical systems affected the Mexican coasts directly, all coming from the eastern North Pacific Ocean. The average number of tropical cyclones to affect Mexico directly (originating from both oceans) for the period from 1970 to 2015 was 4.8 cyclones per year (3.0 from the Pacific and 1.8 from the Atlantic). In addition, "Bill" crossed the Yucatan Peninsula at the low-pressure stage.
PLACE OF LANDFALL
Max. wind speed
MAX. RAINFALL in 24 hours
AND MAX. CUMULATIVE RAINFALL THROUGHOUT THE PERIOD
Bahía Magdalena, Baja California Sur (BCS)
Baja California and BCS
91.5 mm Santa Rosalía, BCS, in 24 h
60 km SSW of Chetumal, Quintana Roo
364 mm Sian Kaan, Quintana Roo in 24 h
387 mm Sian Kaan, Quintana Roo in 48 h
68 km south-west of the Vicente Guerrero dam, Guerrero
8 km WSW of Playa Careyes, Jalisco
165.2 mm in Callejones, Colima, in 24 h
252.5 mm in Cuale, Jalisco. in 196 hours.
35 km to the north of Punta Abreojos, BCS
130 km to the north of Bahía Kino, Sonora
148.0 mm in Santa Rosalía, BCS in 24 h
178.0 mm in Carcamo, Sonora in 96 h
Playa Cuixmala, Jalisco
Jalisco, Colima, Nayarit, Michoacán, Zacatecas, Durango, San Luis Potosí, Aguas-calientes, Nuevo León, Tamaulipas
290.2 mm in Nevado de Colima, Jalisco in 24 h
393.2 mm in Nevado de Colima, Jalisco in 96 h
Summary table of tropical cyclone activity in 2015 in Mexico
General description of the season
Moderate hurricanes (I-II)
Intense hurricanes (III-IV)
Total TCs over Mexico
Cyclones affecting Mexico during 2015 During the 2015 season, four cyclones affected the Pacific Ocean coasts, namely, in chronological order, Tropical Storm "Blanca", Tropical Storm "Carlos", then tropical depression 16-E and finally, intense Hurricane "Patricia". Furthermore, the unstable zone associated with what was later to become Tropical Storm “Bill” affected the Yucatan Peninsula from the Caribbean Sea.
"Blanca" was the first to affect Mexico directly, developing 850 km south of Puerto Angel, Oaxaca, from tropical wave No. 2 on 27 May. After gradually developing and moving west, the unstable zone was raised to 100% probability of developing at 5 p.m. on 31 May. This prompted the issue of warning No. 1 for tropical depression 2 E located 610 km south-southwest of Zihuatanejo, Guerrero. On the morning of 1 June, the depression intensified to Tropical Storm "Blanca", shifting towards the north-west. Owing to favourable sea-surface temperature conditions and the upper atmosphere flow, “Blanca” quickly became a hurricane on 2 June at 4 p.m., and very quickly reached category 4 on the Saffir-Simpson scale at 6 p.m. On 3 June at 10 a.m., maximum sustained wind speeds were 215 km/h with gusts of 260 km/h. As it travelled north-west over the following days, "Blanca" began to lose strength, at the same time approaching the south of the Baja California Peninsula. On 5 June at 4 p.m., in coordination with RSMC in Miami, a surveillance zone was established for tropical storm-force winds for the southern portion of Baja California Sur. On 7 June it weakened to a tropical storm moving north-west and the next day, 8 June, at 7 a.m. the eye of Tropical Storm "Blanca" was located over Bahía Magdalena, BCS, 60 km east-southeast of Cabo San Lázaro, with sustained winds of 75 km/h and gusts of 95 km/h. At 4 p.m. on the 8th, it was downgraded to a tropical depression on land, 55 km east of Punta Abreojos, BCS, crossed the southern part of Baja California and finally at 4 a.m. on 9 June dissipated 40 km east-northeast of San Jose de las Palomas, Baja California.
The maximum cumulative rainfall in 24 h was 91.5 mm in Santa Rosalía, BCS. On 8 June the stations reported maximum winds in Loreto of 68 km/h with gusts of 140 km/h, and in Cabo Pulmo, 68 km/h with gusts of 92 km/h. The lowest pressure, of 992 hPa, was recorded at the Puerto Cortes station. During the storm’s development, from 5 to 7 June, the United States Air Force reserve carried out three missions with the hurricane hunter aircraft, recording winds at flight level of 115 knots (212 km/h) and 81 knots (150 km/h) estimated at ground level. During the storm’s approach, impact and dissipation, a total of 17 coordination calls were made from the National Centre for Weather Forecasting of the Mexican NMS to RSMC Miami to establish, update and discontinue the surveillance and warning zones for "Blanca".
Along its track "Blanca" affected the States of Baja California Sur and Baja California. No deaths or significant damage associated with "Blanca" were reported. The NMS of Mexico issued a total of 49 cyclone warnings plus 15 warnings for the unstable zone with the potential to become cyclonic, and 45 ongoing surveillance maps.
"Carlos" was the second tropical cyclone to make a direct landfall during the 2015 season. It formed in the Gulf of Tehuantepec on 10 June, but developed hurricane strength with maximum sustained winds of 140 km/h and gusts of 165 km/h during the stage of Tropical Storm "Carlos" on 17 June at 7 a.m. The centre of the system was located 8 km west-southwest of Playa Careyes, Jalisco, when it came closest to the land, with maximum sustained winds of 75 km/h and gusts of 95 km/h. Acapulco radar was helpful in determining the position and convection structure of "Carlos" from 12 to 13 June.
Its proximity to land, and the impact of its strong convection cloud area with the mountains of the Sierra Madre Occidental, rapidly weakened the system and, at 1 p.m., it was downgraded to a tropical depression 20 km south of Playa Las Peñitas, Jalisco, with maximum wind speeds of 55 km/h.
The National Meteorological Service of Mexico conducted surveillance of this tropical cyclone, issuing 57 tropical cyclone warnings, 41 ongoing surveillance maps and 14 warnings of low pressure with potential to become cyclonic. The National Meteorological Service of CONAGUA took part in five meetings convened by the National Civil Protection Coordination of the interdepartmental group tracking tropical cyclones, to make an analysis and prognosis for "Carlos".
"Carlos" caused maximum cumulative rainfall in 24 h of 165.2 mm in Callejones, Colima, and 252.5 mm in 196 h in Cuale, Jalisco. No significant damage or deaths associated with Tropical Storm “Carlos” were reported in Mexico.
During the storm’s development, from 15 to 16 June, the United States Air Force reserve carried out two missions with the hurricane hunter aircraft, one of them simultaneously with the reconnaissance flight in the Gulf of Mexico for Tropical Storm "Bill". During the storm’s approach, impact and dissipation, a total of 20 coordination calls were made from the National Centre for Weather Forecasting of the Mexican NMS to RSMC Miami, to establish, update and discontinue the surveillance and warning zones for "Carlos".
Another cyclone that affected Mexico was tropical depression "16-E", which was generated on 20 September off the west coast of Baja California Sur, 145 km west of Cabo San Lázaro, BCS, with maximum sustained winds of 55 km/h, gusts of 75 km/h and moving north-northwest at 22 km/h. During the day of 20 September, the tropical depression continued along its track north-northeast, and at 10 p.m. was located 55 km south of Punta Abreojos, Baja California Sur; it continued to approach the coast of Baja California Sur and, in the early morning of 21 September, was located 35 km south-southeast of Bahía San Juan Bautista, Baja California.
With a maximum sustained wind speed of 55 km/h and gusts of 75 km/h, which it maintained for most of its track, tropical depression 16 made landfall in the south-eastern part of Laguna San Ignacio, 45 km east of Punta Abreojos, BCS, at approximately 0.45 a.m. on 21 September. The National Meteorological Service of CONAGUA took part in two meetings convened by the National Civil Protection Coordination of the interdepartmental group tracking tropical cyclones, to make an analysis and prognosis for "TD 16-E".
TD 16-E continued along its track north-northeast over Baja California Sur and at approximately 3.45 a.m. on 21 September, it went into the Gulf of California from the north-east coast of the State, 33 km south-southeast of the coastal border with the State of Baja California. Over the sea again, TD 16-E continued north-northeast and crossed the Gulf of California. It made landfall on 21 September, around 6 a.m., for the second time on its track, this time on the coast of Sonora, 42 km north-northwest of Bahía Kino, with winds of 55 km/h and gusts of 75 km/h.
Nine tropical cyclone warnings and 14 surveillance maps were issued. Maximum cumulative rainfall in 24 h was 148.0 mm in Mulegé, Baja California Sur, and 110.7 mm in Hermosillo, Sonora, on 20 September 2015. The National Meteorological Service of CONAGUA took part in one meeting convened by the National Civil Protection Coordination of the interdepartmental group tracking tropical cyclones, to make an analysis and prognosis for "TD 16-E".
The fourth cyclone to affect Mexico in 2015 was intense Hurricane "Patricia". On 20 October 2015 at 10 a.m., tropical depression 20-E began to form 330 km south-southeast of Salina Cruz, Oaxaca, with maximum wind speeds of 55 km/h; TD 20-E started from an unstable zone in the Gulf of Tehuantepec, and continued until Saturday 17 October at 7 p.m., when it showed a 10% potential to become cyclonic.
Tropical Depression 20-E continued moving west and at 10 p.m. on the 20th, when it was 335 km south-southeast of Puerto Escondido and developed into Tropical Storm "Patricia" with maximum wind speeds of 65 km/h. "Patricia" continued along its track west-northwest while its winds increased in strength until, on 22 October at 1 a.m., when it was 365 km south-southwest of Acapulco, Guerrero, it intensified into a hurricane with maximum sustained winds of 120 km/h and gusts of 150 km/h.
Hurricane "Patricia" began to intensify rapidly as it continued moving west-northwest at 10 a.m. on the 22nd. When it was 385 km south-southwest of Lázaro Cárdenas, Michoacán, it reached category2 on the Saffir-Simpson scale, with maximum sustained wind speeds of 155 km/h and gusts of 195 km/h; three hours later, it was already a category4 hurricane with maximum sustained winds of 215 km/h and gusts of 260 km/h, 385 km south-southwest of Lázaro Cárdenas, Michoacán. "Patricia" continued to strengthen and at 10 p.m. reached maximum sustained wind speeds of 260 km/h with gusts of 315 km/h, whereupon it was classified as category5 on the Saffir-Simpson scale as an extremely intense hurricane. As it approached the southern coast of Jalisco, the winds of "Patricia" continued to increase in strength at 4 p.m. on 23 October, reaching its strongest when it was 255 km south-southwest of Manzanillo, Colima, with maximum sustained winds of 342 km/h and gusts of 400 km/h.
At approximately 1 p.m., the eye wall of the hurricane came into contact with the southern coast of the State of Jalisco, although the cloud bands of "Patricia" had already spread over the States of Nayarit, Jalisco, Colima and Michoacán. The powerful Hurricane "Patricia" still featured maximum sustained winds of 325 km/h with gusts of 400 km/h at 4 p.m. on the 23rd. At that point, when it was 95 km west of Manzanillo, Colima, because of its proximity to the coast, when its cloud bands struck the Sierra Madre Occidental and absorbed dry air from the continent, it decreased slightly in strength, with maximum sustained winds of 305 km/h and gusts of 380 km/h. It was with that strength that, at 6.15 p.m., it made landfall near Playa Cuixmala, a municipality of La Huerta, Jalisco, on the south coast of Jalisco. A reanalysis by the National Hurricane Centre found that "Patricia" made landfall at category 4 on the Saffir-Simpson scale.
As it moved over Jalisco, without the energy it derived from the sea and affected by the barrier of the Sierra Madre Occidental, Hurricane "Patricia" began to lose strength. At 7 p.m. on the 23rd, it was 5 km east of Cuixmala, Jalisco, with winds of 260 km/h and gusts of 300 km/h, still at category 4. At 10 p.m., "Patricia" was 30 km south-east of Talpa de Allende, at category 4 with winds of 215 km/h and gusts of 260 km/h. At 1 a.m. on the 24th, "Patricia" was located 90 km north-east of Playa Perula, Jalisco, now a category 2 hurricane, with winds of 155 km/h and gusts of 185 km/h, and three hours later it was in the north of Jalisco, 22 km north-northwest of Colotlán, very close to entering the State of Zacatecas, with winds of 120 km/h and gusts of 150 km/h, as a category 1 hurricane.
"Patricia" continued its track north-northeast and at 7 a.m. when it was 55 km north-northeast of the city of Zacatecas, on the border with the State of San Luis Potosí, was downgraded to a tropical storm, with winds of 80 km/h; three hours later, when it was located 25 km east-southeast of Estación Pacheco in the north of the State of Zacatecas, it was downgraded to a tropical depression. Finally, at 4 p.m. on the 24th, tropical depression "Patricia" was located 45 km east-southeast of Saltillo, Coahuila, near the border with the State of Nuevo León, with winds of 45 km/h, close to weakening to a remnant of low pressure.
"Patricia" was cyclone number 20 of the 2015 season in the Pacific Ocean and number 12 to reach hurricane strength. The National Meteorological Service monitored the system, issuing 17 tropical surveillance maps and 36 tropical cyclone warnings, from 10 a.m. on the 20th to 4 p.m. on 24 October, plus 14 warnings of an unstable zone with potential to become cyclonic. CONAGUA issued 31 press releases and held 3 press conferences, and as the NMS, participated in two meetings organised by the National Civil Protection Coordination of the interdepartmental group tracking tropical cyclones to analyse and make forecasts regarding "Patricia”.
Owing to the rapid intensification of Hurricane Patricia and the impact track, the National Civil Protection Coordination body set up the National Emergency Committee, on the instructions of the Office of the President of the Republic, to take preventive measures at all three levels of government, actively meeting from 22 to 25 October at the premises of the National Disaster Prevention Centre.
The maximum cumulative rainfall in 24 hours was 290.2 mm in Nevado de Colima, Jalisco, from 23 to 24 October and 392.2 mm in 96 h at the same station in Nevado de Colima, Jalisco.
Reports of maximum winds during "Patricia” of 192 knots (355 km/h) were measured by the hurricane hunter aircraft at 0647 UTC on 22 October at the north-east wall and a wind of 191 knots (353.7 km/h measured by the NOAA mission at 1734 UTC the same day (according to the NHC final report on "Patricia"). The analysed peak intensity for "Patricia" of 185 knots (342.6 km/h) made this hurricane the most intense on record in the eastern North-Pacific Ocean, surpassing Hurricane "Linda" in 1997. Also according to the NHC report on "Patricia", it is the strongest hurricane on record in both the Atlantic and eastern North-Pacific basins.
The explosive intensification of Patricia from 22 to 23 October is significant. In a 24-hour period ending at 0600 UTC on 23 October, it was estimated that the pressure dropped by 95 hPa and the wind increased from 75 to 180 knots. In one day of intensification by 105 knots, it exceeded the record of 95 knots held by Hurricane Wilma in 2005 in the western Caribbean Sea. The minimum pressure of 872 hPa, recorded at 1200 UTC on 23 October, is the lowest pressure on record in the western hemisphere and the second lowest worldwide. A temperature of 32.2°C at 700 mb measured by the US Air Force reconnaissance aircraft was also recorded at 1733 UTC, setting another record for the hottest temperature measured in an eye of a hurricane. The pressure gradient was 24 mb/nautical mile, one of the most intense in history, and was calculated using data from the aircraft at 0600 UTC.
It is also noteworthy that the rapid intensification was also followed by a period of rapid weakening, beginning at 1800 UTC on 23 October. The pressure of 879 hPa measured by the probe dropped from the aircraft at 1733 UTC rose to 910 hPa at 2044 UTC, increasing at a rate of 8 hPa/hour.
According to the final report of RSMC Miami on "Patricia", the eye of the hurricane made landfall at about 2300 UTC at Cuixmala, Jalisco, about 45 nautical miles west-northwest of Manzanillo, Colima. During operations, it was considered that "Patricia" struck as a category 5 hurricane, with a pressure of 920 hPa, but according to an ex-post analysis of additional data obtained, it weakened more quickly, with a minimum pressure of 934.2 hPa observed at 2300 UTC by the Playa Cuixmala automatic station, located on the coast near Emiliano Zapata. A storm chaser at Emiliano Zapata reported 937.8 hPa on the eastern tip of the eye of the hurricane at 2313 UTC. The runway station measured a pressure of 939.4 hPa at an altitude of 15 metres, equivalent to 941 hPa at sea level. From this, the NHC specialists infer a pressure of 932 hPa in the eye of the hurricane at the time of impact.
The data from the station at Chamela, Jalisco, of 161 knots (298 km/h) with gusts of 183 knots (338 km/h) indicate that the series of wind data from the site were very high and, in agreement with RSMC Miami, unrealistic and questionable. The site has an altitude of 85 metres and is surrounded by complex terrain.
Based on the data and calculations of RSMC Miami, the peak intensity of Patricia at the time of impact was estimated at 130 knots (240 km/h) making it a category 4 hurricane, as it has been estimated that the pressure at the eye of the storm rose by 54 mb in the five hours before impact.
The station at Nevado de Colima, Jalisco, reported 153 knots (283 km/h). Meanwhile the minimum pressures were 937.8 hPa at the Emiliano Zapata station and 934 hPa at Cuixmala.
As the hurricane developed, the United States Air Force reserve hurricane hunter aircraft carried out four missions. During the storm’s approach, impact and dissipation, a total of 17 coordination calls were made from the National Centre for Weather Forecasting of the Mexican NMS to RSMC Miami to establish, update and discontinue the surveillance and warning zones for "Patricia".
According to the post-hurricane survey by the team from the new Deputy Directorate for Hurricanes and Severe Storms of the NMS, CONAGUA, and a member of the United States NWS, there was a narrow band of severe damage along the path of the hurricane’s eye wall near the coast where it struck. The worst damage occurred in the villages of Emiliano Zapata and Chamela, in the municipality of La Huerta, Jalisco.
Functioning of the warning system at the National Meteorological Service of Mexico The National Meteorological Service carried out ongoing surveillance of tropical cyclones throughout the 2015 season. A total of 427 tropical storm advisories were issued for the Pacific Ocean and 63 advisories were issued for the Atlantic Ocean.
Eighty-seven warnings were issued for the Atlantic Ocean and 296 for the Pacific Ocean on account of the unstable zone of low pressure with potential to become cyclonic. During the season NMS issued warning letters addressed to the National Civil Protection Coordination, with copies to the governments of the States that were likely to be affected.
During Hurricane Patricia, additional tools were used, such as Twitter messages from the account @conagua_clima, with 438 messages in seven days, and the CAP format was used to issue 21 warnings, which were published by Google on its Crisis Response portal.