Top Ten Tropical Cyclone Events of 2016 Potentially Influenced by Climate Change

Tropical cyclones—which include all hurricanes, typhoons, tropical storms and tropical depressions—are expected to change in intensity, frequency, location, and seasonality as a result of climate change. Many of the tropical cyclones of 2016 exhibited the type of behavior we expect to see more of due to global warming. Here, then, is a “top ten” list of 2016 tropical cyclone events of the type we should expect to see more of due to global warming.

Examples of the strongest storms getting stronger
Tropical cyclones are heat engines which extract heat energy from the oceans and convert it to the kinetic energy of the storms' winds. Thus, the strongest tropical cyclones are expected to get stronger in a world with warmer oceans. It was not a surprise that in 2016—a year with the warmest ocean temperatures on record, globally—we saw the strongest storms ever observed in the two of the six ocean basins that tropical cyclones commonly occur in. If we include the Northern Hemisphere’s strongest tropical cyclone on record—Hurricane Patrica of October 2015—records have been set in three of the six ocean basins over the past two years. The two all-time record storms in 2016 were Tropical Cyclone Winston in the South Pacific (180 mph winds, tied for strongest Southern Hemisphere storm on record) and Tropical Cyclone Fantala in the South Indian Ocean (175 mph winds.) With the upgrade of Super Typhoon Nock-Ten in post-analysis to Category 5 strength, 2016 also saw eight Category 5 storms, which was the fifth greatest on record (since 1990.)


Figure 1. Global Category 5 tropical cyclones from 1990 - 2016, as rated by NOAA's National Hurricane Center and the U.S. Navy's Joint Typhoon Warning Center. This time series is too short to make definitive conclusions about how climate change may be affecting these storms, though the past three years have had the highest 3-year total of Category 5 storms on record. The eight Category 5 storms of 2016 was the fifth highest yearly total on record.

Two of the Top Five Landfalling Tropical Cyclones Occurred in 2016
In addition, 2016 also saw two of the top five strongest landfalling tropical cyclones ever recorded—Super Typhoon Meranti with 190 mph winds on the Philippines’ Itbayat Island (tied for Earth’s strongest landfall on record), and Tropical Cyclone Winston with 180 mph winds at landfall in Fiji (the 5th strongest tropical cyclone at landfall in recorded history.) As we blogged about in August, landfalling typhoons have become more intense since late 1970s, with the peak winds of typhoons striking the region increasing by 12 - 15% since 1977. “The projected ocean surface warming pattern under increasing greenhouse gas forcing suggests that typhoons striking eastern mainland China, Taiwan, Korea and Japan will intensify further,” wrote the authors of the study we blogged about. “Given disproportionate damages by intense typhoons, this represents a heightened threat to people and properties in the region.”


Figure 2. The most intense world tropical cyclones at landfall, using the advisories taken from the National Hurricane Center in the Atlantic and Eastern Pacific, and the Joint Typhoon Warning Center (JTWC) for the rest of the world's oceans. Both agencies use 1-minute averaging times for their advisories, as opposed to the 10-minute averaging time used to report wind speeds by most international weather agencies and at most international airports. Two of the top five strongest landfalling tropical cyclones ever recorded occurred in 2016: Super Typhoon Meranti and Tropical Cyclone Winston. (Note that Super Typhoon Haiyan was originally assessed to have 195 mph winds at landfall by JTWC, but these were reduced to 190 mph after a post-season reanalysis. Also, Hurricane Camille's winds at landfall have also been reduced in a recent reanalysis, from 190 mph to 175 mph, as were Tropical Cyclone Winston’s winds, from 185 mph to 180 mph.)

February 20: Cyclone Winston Ties for Southern Hemisphere’s Strongest Tropical Cyclone on Record (180 mph Winds)
Just four months after the Northern Hemisphere experienced its strongest tropical cyclone on record—Hurricane Patrica of October 2015, with peak winds of 215 mph off the Pacific coast of Mexico—the Southern Hemisphere answered the challenge by spawning its strongest tropical cyclone ever recorded: Tropical Cyclone Winston, which topped out with 180 mph sustained winds at its peak intensity at 06 UTC February 20. These winds are tied for the highest for any Southern Hemisphere tropical cyclone ever rated by the Joint Typhoon Warning Center (JTWC), along with Cyclone Zoe of 2002 and Cyclone Monica of 2006. Winston's lowest central pressure as estimated by the Fiji Meteorological Service was 915 mb at 06 UTC February 20. This ranks Winston as the 29th most intense tropical cyclone in the Southern Hemisphere by pressure (the record lowest pressure is 890 mb by Cyclone Zoe of 2002.) Winston's top winds were higher than its central pressure might imply because it was a relatively small cyclone, so the wind-generating difference in pressure was packed into a small area. Winston’s landfall on Koro Island in Fiji with 180 mph winds puts Winston in fifth place for Earth's strongest landfalling tropical cyclone on record. Winston killed 44 people in Fiji and did $1.4 billion in damage (32% of Fiji's GDP), making it Fiji’s deadliest and most expensive cyclone in recorded history. Winston’s intensity was aided by ocean temperatures that were more than 1°C (1.8°F) warmer than average.


Figure 3. VIIRS infrared image of Tropical Cyclone Winston at 0057 UTC February 20, 2016. At the time, Winston was the strongest storm ever recorded in the Southern Hemisphere, with sustained winds of 180 mph. Fiji’s Koro Island is in the eye. Image credit: NOAA/NESDIS.

April 18: Fantala Ties for Strongest Tropical Cyclone on Record for the Indian Ocean
Tropical Cyclone Fantala intensified to a Category 5 storm with 175 mph winds (as estimated by the Joint Typhoon Warning Center) north of Madagascar on April 18, 2016, making the cyclone as strong as any on record anywhere in the Indian Ocean. Fantala is tied with Tropical Cyclone Agnielle as the strongest cyclone ever observed in the Southwest Indian Ocean. Fantala and Agnielle both top the record holder for the North Indian Ocean (Super Cyclonic Storm Gonu, June 2007, peak 1-minute winds of 165 mph). Reliable satellite-based records for the Indian Ocean only go back to 1990. Note that some consider Tropical Cyclone Monica (180 mph winds) as the strongest Indian Basin storm. Definitions vary on the boundary of the Indian Ocean, though, and Monica reached peak strength north of Australia in the Arafura Sea, which is considered by several sources, including the CIA World Factbook, to be part of the western Pacific Ocean, not the Indian Ocean. Fantala did $4.5 million in damage to Agaléga, Seychelles, Madagascar and Tanzania, and killed thirteen people in Tanzania. Fantala’s intensity was aided by ocean temperatures that were more than 1°C (1.8°F) warmer than average.


Figure 4. A visible image of Tropical Cyclone Fantala collected at 1025Z (6:25 am EDT) on April 18, 2016, by the Moderate Resolution Imaging Spectroradiometer (MODIS) sensor on board the Aqua satellite. The north tip of Madagascar can be seen at bottom. At the time, Fantala was the strongest tropical cyclone ever observed in the Indian Ocean, with winds estimated at 175 mph. Image credit: NASA.

September 13: Super Typhoon Meranti Ties for Strongest Tropical Cyclone on Record at Landfall (190 mph Winds)
Super Typhoon Meranti made a direct hit on the Philippines’ Itbayat Island on September 13, 2016 as a Category 5 storm with 190 mph winds, tying the storm with Super Typhoon Haiyan (2013) for strongest tropical cyclone at landfall in world recorded history. Meranti’s peak 190 mph winds tied it for tenth strongest tropical cyclone in world history (by 1-minute averaged wind speed), according to the “best-track” data from the Joint Typhoon Warning Center and the National Hurricane Center. In addition, Meranti's 890 mb central pressure made it the seventeenth strongest tropical cyclone on record, by pressure. Meranti’s intensity was aided by ocean temperatures that were more than 1°C (1.8°F) warmer than average.

Officially, here are the top-ten strongest tropical cyclones in world history as rated by NOAA's National Hurricane Center and the U.S. Navy's Joint Typhoon Warning Center, by maximum sustained winds:

1) Hurricane Patricia (2015), 215 mph winds (the only Eastern Pacific storm on this list)
2) Super Typhoon Nancy (1961), 215 mph winds, 882 mb. Made landfall as a Cat 2 in Japan, killing 191 people.
3) Super Typhoon Violet (1961), 205 mph winds, 886 mb pressure. Made landfall in Japan as a tropical storm, killing 2 people.
4) Super Typhoon Ida (1958), 200 mph winds, 877 mb pressure. Made landfall as a Cat 1 in Japan, killing 1269 people.
5) Super Typhoon Haiyan (2013), 195 mph winds, 895 mb pressure. Made landfall in the Philippines with 190 mph winds.
5) Super Typhoon Kit (1966), 195 mph winds, 880 mb. Did not make landfall.
5) Super Typhoon Sally (1964), 195 mph winds, 895 mb. Made landfall as a Cat 4 in the Philippines.
5) Super Typhoon Opal (1964), 195 mph winds
5) Super Typhoon Joan (1959), 195 mph winds
10) Super Typhoon Meranti (2016), 190 mph winds, 890 mb pressure.
10) Super Typhoon Tip (1979), 190 mph winds
10) Super Typhoon Vera (1959), 190 mph winds
10) Super Typhoon Louise/Marge (1964), 190 mph winds
10) Hurricane Allen (1980), 190 mph winds (the only Atlantic storm on this list)

However, it is now recognized (Black 1992) that the maximum sustained winds estimated for typhoons during the 1940s to 1960s were too strong, which would make Meranti of 2016 the third strongest reliably measured tropical cyclone in recorded history for the planet.


Figure 5. At 17:32 UTC September 13, 2016, the eye of Super Typhoon Meranti lay directly over the Philippines’ Itbayat Island, as seen in this infrared VIIRS image. Itbayat recorded sustained winds of 112 mph (10-minute average) and a pressure of 934 mb at 1 am local time, 32 minutes prior to this image. At the time, Meranti was a Category 5 storm with 190 mph winds and a central pressure of 890 mb, and was tied for strongest tropical cyclone at landfall in world recorded history.

Examples of a longer tropical cyclone season in 2016
We might expect tropical cyclone seasons to get longer in the future, due to warming ocean temperatures. The Atlantic hurricane season does appear to be getting longer in the Atlantic south of 30°N and east of 75°W, according to a 2008 paper by Dr. James Kossin of the University of Wisconsin. A 2016 analysis by Dr. Ryan Truchelut of WeatherTiger also supported this idea. However, Juliana Karloski and Clark Evans of the University of Wisconsin-Milwaukee found no trend in tropical cyclone formation dates when looking at the entire Atlantic, for the period 1979–2014. A 2015 study of season length in climate models led by MIT’s John Dwyer yielded mixed results, depending upon which model was used to simulate hurricane activity. Regardless, 2016 had four very notable out-of-season storms, probably influenced by unusually warm ocean temperatures: Hurricane Pali in the Central Pacific in January, Hurricane Alex in the Atlantic in January, Hurricane Otto in the Atlantic on Thanksgiving Day and Super Typhoon Nock-Ten in the Philippines on Christmas Day.

January 11: Hurricane Pali: Earliest Eastern Pacific Hurricane on Record
Peaking at Category 2 strength during its eight-day life, Pali was the earliest tropical storm and earliest hurricane ever observed between the International Date Line and the Americas. Only two other tropical cyclones have been observed in January in the Central Pacific. Pali’s formation was aided by ocean temperatures that were more than 2°C (3.6°F) warmer than average. One might consider January storms to "belong" to the previous year's season from a physical point of view.


Figure 6. MODIS visible satellite image of Hurricane Pali taken on the afternoon of January 12, 2016. At the time, Pali was at peak strength--a Category 2 storm with 100 mph winds. Image credit: NASA.

January 14: Alex Becomes the Atlantic’s First January Hurricane Since 1955
On January 14, Hurricane Alex became the Atlantic’s first January hurricane since 1955. Alex maintained Category 1 strength for almost 24 hours, peaking at 85 mph winds, before weakening to a tropical storm with 65 mph winds and making landfall on January 15 on the island of Terceira in the central Azores, roughly 1000 miles west of Portugal. No major damage or casualties were reported from Alex’s landfall. Only one other January storm since records began in 1851 has made landfall in the Atlantic: Hurricane Alice,  which moved from northeast to southwest over the islands of Saint Martin and Saba on January 2, 1954. The only other January hurricane in the Atlantic was Hurricane One on January 4, 1938. Alex’s ascension to hurricane strength was likely aided by sea surface temperatures that were up to 1°C above average for that time of year—near 22°C (72°F.) These unusually warm waters were part of a huge swath of above-average readings that covered much of the globe, strongly suggesting a link to longer-term climate change. On January 13, both Alex in the Atlantic and Pali in the Pacific were active, making it the first time in recorded history to have simultaneous January named storms in both the Atlantic and Pacific.


Figure 7. MODIS visible satellite image of Tropical Storm Alex at 9:20 am EST January 15, 2016. About an hour earlier, Alex’s western eywall passed over the Azores island of Terceira (black outline below the center of Alex). Image credit: NASA.

November 24: Hurricane Otto, Strongest Atlantic Hurricane so Late in the Year
We expect landfalling hurricanes on U.S. holidays like Labor Day (in September), on Independence Day (July 4), and even on occasion Memorial Day (in May.) But on Thanksgiving Day? That was unheard of until 2016, when deadly Hurricane Otto, the first hurricane known to make landfall on Thanksgiving Day, hit Nicaragua as a Category 2 storm with 110 mph winds on November 24. Otto was the Atlantic’s strongest hurricane on record so late in the year, and was the first hurricane to pass directly over Costa Rica since records began in 1851. Otto killed 17 people, making it the third latest deadly tropical cyclone in Atlantic recorded history. (The only later ones: Tropical Storm Olga, which killed 40 people in the Dominican Republic after landfall on December 11, 2007, and Tropical Storm Odette, which killed eight people in the Dominican Republic after landfall on December 6, 2003.) Otto’s formation was aided by ocean temperatures that were up to 1°C (1.8°F) warmer than average.


Figure 8. MODIS satellite image of Otto taken at approximately 11 am EST, November 24, 2016--Thanksgiving Day. At the time, Otto was a Category 2 storm with 110 mph winds about to make landfall in Nicaragua as the strongest Atlantic hurricane ever observed so late in the year. Image credit: NASA.

December 25: Super Typhoon Nock-Ten, Strongest Landfalling Northwest Pacific Typhoon so Late in the Year
Strong typhoons can occur year-round in the Northwest Pacific, but there has never been a landfalling typhoon as strong as Super Typhoon Nock-Ten so late in the year. After peaking as a Category 5 storm with 160 mph winds at 3 UTC Christmas Day (as per post-analysis by JTWC), Nock-Ten made landfall in the Philippines at 6 UTC Christmas Day, 2016 as a Category 4 storm with 155 mph winds and a central pressure of 915 mb. The only stronger typhoon ever recorded so late in the year was Super Typhoon Hester, which peaked as a Category 5 storm with 185 mph winds on December 31, 1952, about 1,000 miles east of the Philippines. Hester recurved out to sea without affecting any land areas. Nock-Ten’s formation was aided by ocean temperatures that were up to 1°C (1.8°F) warmer than average.


Figure 9. MODIS satellite image of Nock-Ten taken at approximately 06 UTC December 25, 2016. At the time, Nock-Ten was a Category 4 super typhoon with 155 mph winds, approaching the Philippines. Image credit: NASA.

Examples of a geographical shift in tropical cyclone activity in 2016
As I explained in my August 2014 post, Climate Change May Increase the Number of Hawaiian Hurricanes, warming sea surface temperatures may help shift the tracks of Eastern Pacific hurricanes closer to Hawaii. And for the third consecutive year, Hawaii saw a highly unusual level of tropical cyclone activity of activity in 2016, thanks, in part, to record- and near record-warm ocean temperatures.

July 23: Darby Hits Hawaii, Then Makes the Closest Pass to Honolulu by a Tropical Storm in Recorded History
Tropical Storm Darby made a direct hit on the Big Island of Hawaii on July 23, 2016, becoming just the fifth named storm since 1949 to make landfall on a Hawaiian Island. The next day, Darby made the closest approach on record by a tropical storm to the island of Oahu, which resulted in torrential rains in excess of 10 inches. Darby passed just 40 miles to the south and west of Honolulu with sustained winds of 40 mph. Darby’s formation was aided by ocean temperatures that were more than 1°C (1.8°F) warmer than average.


Figure 10. Another storm parade for Hawaii: VIIRS visible satellite image of ex-Hurricane Celia, Hurricane Darby, and Tropical Storm Estelle as seen on July 17, 2016. Image credit: NASA.

Examples of increased tropical cyclone rainfall in 2016
Increased evaporation from warmer oceans is expected to increase tropical cyclone rainfall by an average of 20% by the year 2100, agree hurricane scientists. Record- to near-record-warm ocean temperatures over the Atlantic waters near the U.S. in 2016 led to two instances of record- to near-record atmospheric moisture levels and record rainfall amounts in association with tropical systems: the “no-name” storm over Louisiana in mid-August, and Hurricane Matthew in October along the Southeast U.S. coast.

Mid-August: Louisiana’s No-name Storm
A slow-moving tropical disturbance that was never officially classified as a tropical depression meandered over Louisiana in mid-August, dumping colossal amounts of rain. The extreme record flooding that resulted caused 13 deaths and an estimated $10 - 15 billion in damage, making it the most expensive natural disaster in the U.S. in 2016. Some parts of Louisiana recorded more than 20" of rain in 48 hours, which qualifies as a 1-in-1,000 year rainfall event (having a 0.1 percent chance of occurring at a particular location in any given year), according to the NWS Lower Mississippi River Forecast Center. The highest rainfall total from the storm was 31.39” in Watson, Louisiana. The storm system carried near-record amounts of atmospheric moisture, drawn from the Gulf of Mexico and northwest Atlantic, where sea-surface temperatures (SSTs) were at near-record levels—more than 1°C (1.8°F) warmer than average. A fast-track climate change attribution study published one month after the storm found that climate change approximately doubled the chances for the type of heavy downpours that caused the devastating flood.

This was Louisiana’s second 20” deluge of the year; on March 8 - 12, an upper-level low pressure system stuck in place over Texas brought a flow of moist Gulf of Mexico air with record levels of atmospheric moisture for this time of year to Louisiana, resulting in widespread 1-in-200 year rainfall amounts of 15 - 20”. The storm killed five, and total damage in Louisiana and Texas was estimated at $1.5 billion by insurance broker Aon Benfield.


Figure 11. Major flooding in Prairieville, Louisiana on August 12, 2016 from a no-name tropical disturbance that caused $10 - $15 billion in damage. Image credit: @presleygroupmk/twitter.com.

October 7 - 9: Hurricane Matthew Brings Record Rains and a Record Storm Surge to the Southeast U.S.
The main story of the 2016 Atlantic hurricane season was Hurricane Matthew, the Atlantic’s first Category 5 storm since Felix of 2007. Matthew lasted as a major hurricane for eight days from Sept. 30 to Oct. 7, and devastated Haiti as a Category 4 storm on October 4, killing at least 546, making it the Atlantic’s deadliest hurricane in 11 years. Matthew grazed the coast of Florida and Georgia before making landfall in South Carolina on October 8 as a Category 1 hurricane with 75 mph winds. Matthew’s storm surge brought water levels that were the highest ever observed along portions of the coasts of Northern Florida, Georgia and North Carolina, beating records that had been set as long ago as 1928. Some of these records—and much of the coastal damage—would not have occurred without sea level rise over the past century from human-caused global warming. In addition, near record-warm ocean waters more than 1°C (1.8°F) warmer than average contributed to atmospheric moisture levels that were the highest on record over portions of Florida and South Carolina as Matthew moved up the coast, allowing the hurricane to dump 1-in-1000 year rains in some areas of South Carolina and North Carolina. Matthew killed 49 people in the U.S., 28 of them in North Carolina, and U.S. damage was estimated at up to $10 billion. This would make Matthew the 17th most expensive hurricane in U.S. history.


Figure 12. Twenty-four hour rainfall amounts from Hurricane Matthew on October 6 - 10, 2016 over portions of South Carolina and North Carolina were so extreme, that one could expect them to have a recurrence interval of 1-in-1000 years based on past climatology (dark blue colors).

Links
Hurricane Patricia's 215 mph Winds: A Warning Shot Across Our Bow (my 2016 blog post)
Fewer but Stronger Global Tropical Cyclones Due to Ocean Warming (my 2015 blog post)
Hurricanes and Climate Change: Huge Dangers, Huge Unknowns (my 2013 blog post)
Climatesignals.org analysis of Hurricane Matthew
Climatesignals.org analysis of Super Typhoon Meranti

Jeff Masters