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Meranti Approaches China Coast After Sweeping Past Taiwan

By: Bob Henson and Jeff Masters 6:50 PM GMT on September 14, 2016

One of the strongest tropical cyclones in modern weather history, Typhoon Meranti, was approaching the southeast China coast late Wednesday night local time (Wednesday afternoon EDT). As of 16Z (noon EDT), Meranti was located by the Japan Meteorological Agency near 23.8°N, 118.6°E, or about 50 miles southeast of the coastal city of Xiamen in China’s Fujian province. On its steady northwest track at about 12 mph, Meranti should make landfall near or just south of Xiamen at around 4 pm EDT.

Meranti tracked just south of Taiwan’s mountainous south end over the last 24 hours, which disrupted its circulation and put a huge dent in its top sustained winds. You can see the weakening of the typhoon as it passed by Taiwan on this long radar loop from Taiwan compiled by Brian McNoldy. At noon EDT Wednesday, Meranti’s 10-minute average winds were down to 105 mph, according to JMA. The 1-minute average wind used by U.S. agencies is typically around 14% greater than the 10-minute average, so the JMA value would correspond roughly to a 115-mph low-end Category 3 hurricane. Meranti could weaken a bit further before landfall.


Figure 1. This enhanced infrared satellite image shows Typhoon Meranti nearing the coast of China at 1700Z (1:00 pm EDT) Wednesday, September 14, 2016. Image credit: NOAA/NESDIS.

In spite of its decline, Meranti retains the potential to produce a major storm surge along the China coast. It takes some time for the huge amounts of water being pushed by a major hurricane or typhoon to subside, even after the storm itself weakens. Two good examples are Hurricane Katrina and Hurricane/Superstorm Sandy, both of which produced catastrophic storm surge despite significant weakening of their top winds in the hours before landfall. Meranti’s surge would be worst just to the north of its center, and this part of the storm is aimed at the city of Xiamen (population 3.5 million), one of the world’s 20 busiest ports for container shipping. Because China’s coast is so densely populated, storm surge can threaten huge numbers of people. In 1994, Typhoon Fred struck the province of Zhejiang after weakening from a Category 4 to a Category 1 storm. Fred still managed to produce a top surge of just under 9 feet that affected more than 22 million people, as noted by storm surge expert Hal Needham.

Torrential rains are another serious threat from Meranti across east central China. Widespread 3” - 6” rains can be expected near the typhoon’s track as it moves inland, with localized 10” - 15” amounts quite possible. The heavy rain may extend further north later this week, toward Shanghai, as Meranti’s remnants are swept northward. In 1983, Typhoon Wayne followed a very similar track to Meranti, passing just south of Taiwan and weakening from a Category 4 to Category 1 before landfall several dozen miles south of Xiamen. Coastal and inland flooding linked to Wayne in Fujian and Guangdong provinces led to 105 deaths and the collapse of some 30,000 structures.


Figure 2. A local resident removes a rock from a blocked road in southern Pingtung county as Typhoon Meranti slashes southern Taiwan on September 14, 2016. Image credit: Sam YehAFP/Getty Images.


Figure 3. Power lines downed by Meranti partially block the road in southern Taiwan’s Pingtung county on September 14, 2016. Image credit: Sam YehAFP/Getty Images.

Meranti’s impacts on Taiwan and the Philippines
Meranti’s path just south of Taiwan kept the typhoon’s fiercest winds and waves focused on the sparsely populated southeast flank of the island, which greatly reduced the impact on people and property. The South China Morning Post reported that at least one person was missing, 35 were injured, and power and water supply was knocked out to more than 600,000 homes, according to Taiwan’s Central Emergency Operation Centre. The largest city affected was Kaohsiung, on Taiwan’s southwest coast, which received a glancing but still powerful blow as Meranti swept past to the south. Kaohsiung International Airport reported top sustained winds of 71 mph at 12:30 pm local time Wednesday, with a gust to 112 mph shortly thereafter. A number of rainfall amounts topping 500 mm (about 20”) were reported in far southern Taiwan. Xidawushan, in Taiwu Township (in the mountains about 25 miles east of Kaohsiung) reported a total of 799.5 mm (31.48”) from midnight to midnight local time Wednesday, September 14. Of that total, 685 mm (26.97”) fell in just 12 hours. (Thanks to Michael Theusner and Jérôme Reynaud for these rainfall statistics.)

One of the most poignant of many stunning satellites images of Meranti was the view in Figure 4 (below), with Meranti’s eye completely enveloping the tiny Philippines island of Itbayat and its 3,000 residents. As of midday Wednesday, there was no word of conditions on the island. Channel NewsAsia reported that the Philippines government would be sending a civil defense team to Itbayat at a time yet to be determined.


Figure 4. At 17:32 UTC Tuesday (1:32 pm EDT Tuesday or 1:32 am local time Wednesday), the eye of Meranti lay directly over the Philippines’ Itbayat Island, as seen in this visible-light image from Japan’s Himiwari-8 satellite, taken in the bright moonlight that evening. 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 185 mph winds and a central pressure of 890 mb. Thanks go to WU member Barefootontherocks for posting this image in the blog comments.

History of major typhoon landfalls in China
China has a long history of major typhoon landfalls. Since record keeping in the Northwest Pacific began in 1945, there have been two Category 5 storms to make landfall in China, twelve Category 4 storms, and eighteen Category 3 storms. We constructed the list below using data from the Joint Typhoon Warning Center for the Northwest Pacific, as plotted on NOAA’s Historical Hurricane Tracks website. These storms were all rated Category 3 or stronger in their last 6-hour position before they made landfall in China:

Landfalls South of Hong Kong

Category 5:
160 mph, Super Typhoon Rammasun, July 18, 2014

Category 4:
140 mph, Typhoon Hagupit, September 24, 2008
140 mph, Typhoon Ruby, September 5, 1964
140 mph, Typhoon Kate, September 25, 1955
130 mph, Typhoon Vicente, July 23, 2012
130 mph, Typhoon Betty, October 31, 1953

Category 3:
125 mph, Typhoon Sally, September 9, 1996
125 mph, Typhoon Susan, September 18, 1953
125 mph, Typhoon Rose, August 16, 1971
115 mph, Typhoon Pamela, November 8, 1972
115 mph, Typhoon Ophelia, August 14, 1953
115 mph, Typhoon Winnie, July 1, 1964
115 mph, Typhoon Freda, July 15, 1965

Landfalls North of Hong Kong

Category 5:
160 mph, Super Typhoon Cora, September 5, 1966

Category 4:
150 mph, Super Typhoon Saomai, August 10, 2006
150 mph, Super Typhoon Alice, September 3, 1966
150 mph, Super Typhoon Wanda, August 1, 1956
145 mph, Typhoon Rita, September 1, 1953
140 mph, Typhoon Bilis, August 23, 2000
140 mph, Typhoon Nina, August 16, 1953
130 mph, Typhoon Grace, September 4, 1958

Category 3:
125 mph, Typhoon Joan, August 30, 1959
120 mph, Typhoon Khanun, September 11, 2005
120 mph, Typhoon Wipha, September 19, 2007
120 mph, Typhoon Hope, August 2, 1979
120 mph, Typhoon Amy, July 18, 1991
120 mph, Typhoon Dujuan, September 2, 2003
115 mph, Typhoon Usagi, September 22, 2013
115 mph, Typhoon Viola, July 28, 1969
115 mph, Typhoon Abe, September 14, 1993
115 mph, Typhoon Harriet, July 29, 1952
115 mph, Typhoon Tim, July 10, 1994

Meranti tied for tenth strongest tropical cyclone in history (by wind)
Meranti peaked at 2 pm EDT Tuesday, September 13, with sustained winds of 190 mph. This makes it tied 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 at the time made it the seventeenth strongest tropical cyclone on record, by pressure.

Officially, here are their top-ten strongest tropical cyclones in world history, 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, 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. Dr. Hugh Willoughby, former head of NOAA's Hurricane Research Division, had this to say about the winds measured in Super Typhoon Nancy and the other high-end typhoons from this list from the 1960s:

"I would not take the winds seriously because reconnaissance meteorologists estimated them visually. A decade later when I flew with the VW-1 hurricane hunters, we had the same Doppler system used to measure the winds of Typhoon Nancy. It tracked the aircraft motion relative to the (possibly moving) sea surface. It couldn't get a coherent signal in high winds because the beam reflected from both the actual surface (whatever that is) and blowing spray. Visual estimates are dubious because the surface (under the eyewall!) is hard to see unless you are flying below cloud base (200-300 m) and also because appreciably above 115 mph, it's completely white with blowing spray. We used to think that we could estimate stronger winds from the decreasing coverage of slightly greenish patches where the spray was thinner. I now think that we were kidding ourselves. In those days the distinctions among wind gust, sustained one-minute winds, etc., were less well defined than they are now. So we may never know what the 1960s reconnaissance data really means!”

For a complete update on activity in the Atlantic, including unexpected Tropical Storm Julia, see our post from earlier Wednesday. Apologies for the site issues and lack of blog access this morning; we had a disk issue that was causing us trouble.

Bob Henson and Jeff Masters



Video 1. Dan Lindsey (CIRA/CSU) says: “Check out the interesting gravity wave action likely in response to winds interacting w/ terrain.” Image credit: Himiwari-8 satellite loop courtesy @DanLindsey77.



Video 2. Bernadette Woods Placky (Climate Central) says: “Video of #Meranti battering Pintung, Taiwan from my friend Dr. ChiMing Peng.” Image credit: @BernadetteWoods, via @weatherrisk.

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