Cyclone Winston devastated the South Pacific island nation of Fiji on Sunday morning, with the Fiji Broadcasting Corporation reporting 21 confirmed dead and four missing at sea as of Monday afternoon (U.S. time).

Winston made landfall on the northeast side of Fiji’s island of Viti Levu, its most populated island and the location of its capital, Suva. More than 8,400 were in evacuation centers in the country.

Cyclones and typhoons are structurally the same as hurricanes, and they all fall under the classification of tropical cyclones. According to Weather Underground, Winston had an estimated maximum wind speed at landfall of 185 mph, with gusts to 225 mph. Based on estimates from the U.S. Joint Typhoon Warning Center, this makes it the strongest tropical cyclone on record in the Southern Hemisphere.

Globally, Winston was the second strongest tropical cyclone on record at its time of landfall. Only Super Typhoon Haiyan was stronger when it hit the Philippines in 2013 with winds of 190 mph.

cyclone winston

Winston is tied with two other tropical cyclones for second place: Super Typhoon Joan hit Taiwan in 1959 and the Great Labor Day Hurricane devastated the Florida Keys in 1935. For reference, last fall’s Hurricane Patricia, which was in the eastern Pacific, briefly had maximum sustained winds at 210 mph, but it weakened before making landfall in a sparsely populated portion of the Mexican coast.

The ongoing El Niño promotes favorable conditions for tropical cyclone development in the South Pacific, as warm ocean waters fuel tropical cyclones. Tellingly, ocean temperatures near Fiji a few days before impact were around 85°F, according to a NOAA analysis. In the short term, this was about about 3°F above normal. In the longer term, a NOAA analysis indicated that the average ocean temperature in the area around Fiji has risen 1°-2°F since 1901.

The track of the storm has been exceedingly unusual, originally passing south of Fiji from southwest to northeast. But once it was 700 miles east of Viti Levu, it turned back to the west on its way to making landfall.

forecast cyclone winston
forecast cyclone winston

Previous (black) and forecast (magenta) track of Cyclone Winston as of 7am ET, Feb 22, 2016.

From a projection standpoint, more analysis is required to determine how much of a role climate change had in the strength of Winston. According to the IPCC Fifth Assessment report, even while it is likely that the global frequency of tropical cyclones will either decrease or remain essentially unchanged, there will likely be an increase in both global average maximum wind speed and rain rates.

As of Monday afternoon, Winston remained a moderate tropical cyclone, but it is expected to turn southwest and weaken over the Pacific over the next few days.