Very Intense Tropical Cyclone Quinn
Very Intense Tropical Cyclone (MFR)

Quinn at its record-breaking peak intensity directly before landfall over Durban, South Africa
Formed March 2
Dissipated April 21
Accumulated Cyclone Energy 319.7
Highest winds 520 mph (450 kts, 835 km/h)
(10-minute sustained)
Lowest pressure 505 mbar (hPa; 14.91 inHg)
Damages $60 billion (2018 USD)
Direct Fatalities 1,345,976
Indirect Fatalities 6,984,232
Missing 13,927,695
Areas affected Mauritius, Rodrigues, Réunion, Mozambique, South Africa, Swaziland, Lesotho, Namibia, Uruguay, Argentina, and Chile
Part of the
2017-18 South-West Indian Ocean cyclone season

Cyclone Quinn was an exceptionally long-lived tropical cyclone which transversed the western half of the Indian Ocean and southern Atlantic Ocean, making devastating strikes on Madagascar and South Africa. Less severe impact occurred in Uruguay and Argentina, where Quinn hit at a weaker intensity. With a size exceeding 2,700 miles (4,345 km), the cyclone was by a significant margin the largest tropical cyclone on Earth, doubling the previous record set by Typhoon Tip in 1979. Combined with its winds of 655 mph (570 knots, 1055 km/h) and pressure of 505 mbar (hPa; 14.91 inHg), Quinn killed over eight million people and caused billions of dollars in losses across Africa and South America.


At this point, the South-West Indian Ocean was experiencing its worst cyclone season in decades, with Madagascar, Mozambique, South Africa, and even Swaziland being effectively wiped off the map by systems with unprecedented strength striking just days apart. Worsening the situation was the fact an extraordinarily powerful La Niña that caused utter destruction in the previous Atlantic season had warmed sea surface temperatures (sea surface temperatures) to nearly 140°F (60°C) in the entire Indian Ocean, with values of 122°F (50°C) extending as far south as Antarctica. Scientists feared it would only be a matter of time before a potential super storm, perhaps a massive, unimaginably destructive hypercane, would develop. Following Quinn's formation, their worst nightmare verified.

Meteorological history

Cyclone Quinn began its life as a tropical wave which detached from the Intertropical Convergence Zone northwest of Australia on February 28. At this point, Cyclones Nate and Ophelia were devastating Madagascar and South Africa, and Pat was spinning harmlessly out at sea. Despite slight vertical wind shear enclosing the system, sea surface temperatures exceeding 104°F (40°C) very quickly spawned a tropical disturbance at 1200 UTC on March 2, as noted by Météo-France (MFR). With a westwards forward speed of 4 mph (6 km/h), the disturbance rapidly intensified to a tropical depression within four hours and then a moderate tropical storm three hours later, named Quinn by MFR. Around this time, the Joint Typhoon Warning Center (JTWC) also initiated advisories on the storm, reporting one-minute winds of 45 mph (40 knots, 75 km/h) Due to the shear conditions, Quinn leveled off in intensity for three days as it tracked extremely slowly westwards, aided by the influence of a trough. By March 6, the wind shear had completely relaxed, the air enclosing the cyclone was exceptionally moist, and sea surface temperatures were beyond 120°F (49°C) in Quinn's forecast path. Due to its large size of roughly 500 miles (805 km), however, it only gradually intensified to severe tropical storm intensity on MFR's cyclone scale, doing so at 0300 UTC March 7. Ultimately, even Quinn's large size proved no obstacle; Dvorak estimates sampled at 0900 UTC that same day indicated a strong Category 1 cyclone on the Saffir-Simpson Hurricane Scale (SSHS). Consequently, three hours later, the system explosively intensified (EI) to ten-minute sustained winds of 100 knots (115 mph, 185 km/h) with a pressure of 938 mbar (hPa; 27.70 inHg) per MFR and one-minute winds of 120 knots (140 mph, 225 km/h) as estimated by the JTWC. As sea surface temperatures swelled to 135°F (57°C), Quinn started a second round of very intense EI, and at 1800 UTC March 7, MFR reported an intensity of 190 mph (165 knots, 305 km/h) with a pressure of 867 mbar (hPa; 25.60 inHg), while the JTWC reported winds of 240 mph (210 knots, 385 km/h). With this, Quinn had beaten Typhoon Forrest in 1983 as the fastest-strengthening tropical cyclone on record and expanded to a size of roughly 1,600 miles (2,575 km). Meteorologists worldwide described this as "something you would expect from a disaster movie...this is well beyond anything we could have ever accurately forecasted". Fortunately, due to its expansive size, Quinn held off on its development pace, although it continued to intensify gradually and suck moisture from the atmosphere like a hungry child gobbling down food for another two weeks. Later, on March 15, as Quinn's forward speed increased to 9 mph (14 km/h), it began a slower round of rapid intensification (RI) as it closed in on Réunion. At 0243 UTC on March 16, the unimaginable cyclone's center of its radius of maximum winds passed directly over island, sending major-hurricane force winds as far away as Mauritius, 110 miles (177 km) northeast of Réunion, hurricane-force winds as far away as Rodrigues, 350 miles (563 km) from Mauritius, and gale-force winds 1,000 miles (1,609 km) in all directions. Winds were estimated to be at 345 mph (300 knots, 555 km/h) with a pressure of 786 millibars (hPa; 23.21 inHg) per MFR, and winds were roughly 455 mph (395 knots, 730 km/h) based on JTWC estimates.

After clearing Réunion on March 17, Quinn began to execute an eyewall replacement cycle (ERC). Scientists prayed this would be the final saving grace for Madagascar and southern Africa. However, the ERC only weakened Quinn to an MFR intensity of 220 mph (190 knots, 355 km/h), with a pressure of 846 mbar (hPa; 24.98 inHg), and a JTWC intensity of 290 mph (250 knots, 465 km/h). Moreover, as the outer rainbands of the monster were already slamming into Madagascar and sea surface temperatures in the vicinity exceeded 150°F (66°C), Quinn instantly began an even stronger round of EI and its forward speed increased to 13 mph (21 km/h). By March 19, the cyclone had reached winds of 405 mph (350 knots, 650 km/h) and a pressure of 632 mbar (hPa; 18.66 inHg) according to MFR estimates and 500 mph (435 knots, 805 km/h), becoming a hypercane in less than 48 hours. Furthermore, Quinn was inhaling sea surface temperatures now around 180°F (82°C), prompting its size to increase to its record-breaking diameter of 2,700 miles (4,345 km). EI continued to happen like the snap of the figure as the storm, described as "unthinkably unrealistic" by international news agencies. Finally, on March 24, Quinn stopped its intensification. It now had the following features, in addition to being perfectly symmetric:

  • An eye 75 miles (121 km) wide,
  • An eyewall 160 miles (257 km) wide,
  • Windspeeds of 495 mph (430 knots, 795 km/h) per MFR and 560 mph (485 knots, 900 km/h) per the JTWC,
  • A pressure of 594 millibars (hPa; 17.54 inHg),
  • A radius of maximum winds 120 miles (193 km) wide,
  • Major hurricane-force winds extending 400 miles (644 km) from the center,
  • Hurricane-force winds extending 1,355 miles (2,181 km) from the center,
  • Gale-force winds extending 2,450 miles (3,943 km) from the center, and
  • A storm surge potential of 500 feet (152.44 meters) with accompanying waves of 200 feet (60.97 meters).

At this point, Madagascar and even Mozambique were being severely affected by Quinn.