Even as the remains of Super Typhoon Meranti
continue to spin down in the rugged mountains of eastern China, there’s another storm on the horizon. Typhoon Malakas
, located about 600 miles southeast of Taipei, Taiwan, is gaining strength and could take a swipe at Taiwan on Saturday local time. In its update at 18Z (2:00 pm EDT) Thursday
, the Joint Typhoon Warning Center estimated that Malakas had peak winds of 105 mph and was moving northwest at about 16 mph. A tiny eye has been appearing intermittently on satellite imagery in the midst of Malakas’s large circulation.Figure 1.
Enhanced infrared image from Japan’s Himiwari-8 satellite of Typhoon Malakas as of 1900Z (3:00 pm EDT) Thursday, September 15, 2016. Image credit: NOAA/NESDIS
Track forecast for Malakas as of 1800Z (2:00 pm EDT) Thursday, September 15, 2016.
Malakas is on a classic recurvature track, swinging around a strong upper-level ridge to its northeast. The GFS, European, and UKMET models--our most reliable models for track prediction--all bring Malakas within about 100-150 miles of Taiwan’s northeast corner this weekend. It wouldn’t take much of a westward swing in Malakas’s track to put Taiwan at risk. JTWC is projecting
that Malakas will be a high-end Category 3 storm at that point, with top sustained winds of 125 mph, and it could be stronger. JTWC notes
that Malakas could go through a period of rapid intensification, as it will be drawing on a moist atmosphere, warm sea-surface temperatures of 29-30°C, and light to moderate wind shear (10-20 knots).If it misses Taiwan, Malakas will be on course to rake some of Japan’s Yaeyama Islands, located 50 to 150 miles east of Taiwan. Early next week, Malakas will likely sweep northeast as a weakening typhoon or tropical storm along or near the spine of Japan’s main island, Honshu.For such a powerful storm, Meranti’s toll is light
Taiwan and China are breathing sighs of relief after their encounter with formidable Super Typhoon Meranti. Peaking at 190 mph, Meranti’s satellite-estimated sustained winds put the storm in a tie for the tenth strongest winds
in global records for any tropical cyclone, including hurricanes and typhoons.
Fortunately, Meranti’s path stayed just off the south coast of Taiwan, and the typhoon had weakened to Category 2 strength with 105 mph sustained winds
by the time it made landfall on the China coast in the city of Xiamen. Nevertheless, some 300,000 of Xiamen’s 3.5 million residents were evacuated, and the others went through a wild night. The Xiamen airport recorded wind gusts to 87 mph just ahead of Meranti’s center at 3 am Thursday, along with a one-hour drop in barometric pressure of 19 millibars (from 983 to 964 millibars). Meranti is the strongest typhoon to strike China’s Fujian province in records going back to 1949, according to the nation’s Xinhua news service
. The historic Dongguan Bridge, built in 1145, was destroyed by the flood. Rainfall of more than 400 millimeters (15.75”) was reported in Zhejiang province as Meranti slogged inland. According to the insurance broker Aon Benfield, China’s Ministry of Civil Affairs (MCA) reported that Meranti had left at least seven people killed or missing and dozens more injured, with many windows shattered in mid- and high-rise buildings and many trees downed into homes, businesses and vehicles. At least 1.65 million people lost power in Fujian province alone. Several dozen injuries were reported in Taiwan
, where more than 600,000 homes lost power. There has been no word yet on the fate of the 3000 residents of Itbayat, the tiny Philippine island just south of Taiwan that was encompassed by Meranti’s eye
Millions of people were waylaid by cancelled or postponed flight and train schedules as Meranti arrived during East Asia’s Mid-Autumn Festival
, a traditional multi-day event commemorating the fall harvest and centered on the full moon that falls between mid-September and mid-October. A two-story-high inflatable moon created as part of the festival went rogue in Meranti’s winds
in Fuzhou. The moon caused no major damage but prompted a stir on social media (see embedded video at bottom).Figure 3.
A man walks past a destroyed building in Xiamen in China's eastern Fujian province after Typhoon Meranti made landfall on September 15, 2016.Figure 4.
An aerial view of a flooded road in the city of Fuzhou, about 100 miles north of Typhoon Meranti’s landfall, on September 15, 2016. Image credit: VCG, via Getty Images.New study: Landfalling typhoons have become more intense since late 1970s
Rapidly intensifying typhoons (of which Meranti is a textbook example) are a growing threat to East and Southeast Asia, according to a study published this month in Nature Geoscience
. The study found that the peak winds of typhoons striking the region have increased by 12 - 15% since 1977. This trend appears to be mainly the result of faster intensification rates, as the typhoons are passing over increasingly warmer waters en route to landfall.
Wei Mei and Shang-Ping Xie (Scripps Institution of Oceanography) analyzed the tracks and strengths of nearly 600 typhoons that occurred from 1977 (when the Japan Meteorological Agency began cataloguing typhoon wind speed) through 2013. The authors drew on both JMA and JTWC “best track” data sets, which are the highest-quality typhoon records from each agency. For consistency with JTWC, the JMA wind reports were converted from 10-minute to 1-minute averages. Although a particular storm’s evolution can vary from one dataset to the other, the overall findings of the study were consistent across both datasets. Because of the general increase in peak typhoon strength, the average number of Category 4 and 5 typhoons per year in the Northwest Pacific has jumped from less than 5 to more than 7.
About half of all typhoons in the Northwest Pacific make landfall somewhere, and this is where the trends found in the study are most pronounced. The authors broke the 37-year typhoon record into four clusters, each of which corresponds to a particular region of typhoon development and track. The two clusters that make up most of the landfalling typhoons showed intensification rates that grew by more than 60% over the study period, with an extra 3 knots now being added every six hours during intensification periods. Atmospheric dynamics (including vertical wind shear) don’t show any consistent trend in the study area, but sea surface temperatures have risen, especially just east of Asia. In turn, that has boosted the maximum potential intensity of typhoons approaching the coast of East and Southeast Asia. Figure 5.
Most of the North Pacific Ocean is running warmer than usual right now, as depicted by these departures from average sea surface temperature for September 15, 2016 (in degrees C). Image credit: NOAA Office of Satellite and Product Operations
Increasing SSTs are a hallmark of our warming planet, and though Mei and Xie did not attempt to directly link the trends they found to human-produced climate change, they do note that the findings on potential intensity are consistent with output from climate models (CMIP5) used in the most recent IPCC report. These models show that SSTs will be warming more quickly this century across the subtropics than over the deep tropics. “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. “Given disproportionate damages by intense typhoons, this represents a heightened threat to people and properties in the region.”
A previous study
found little trend in the strength and frequency of landfalling typhoons from 1950 to 2010. However, the planet’s atmosphere and oceans did not begin their decade-by-decade warming streak until the 1980s. In a global study examining the period 1975-2010, Greg Holland and Cindy Bruyére (National Center for Atmospheric Research, or NCAR) found that more tropical cyclones were reaching Category 4 and 5 intensity
over time, with a declining share at the Category 1 and 2 levels. In an email, Holland added: “While not emphasized in our paper, we did find that globally the increasing proportions could be contributed both to increasing intensification rates (in agreement with Mie and Xie) and to longer periods spent over warm oceans, and that both seemed to be equally important.”
Addressing the new study by Mei and Xie, NCAR’s James Done said in an email: “It's a very nice paper, and the results are generally in line with how we think the intensity distribution would change under warming.” The NCAR group has produced a Cyclone Damage Potential index
that combines forward speed and storm size with peak winds to gauge a tropical cyclone’s overall ability to wreak havoc. This index has shown a linear increase over the West Pacific for landfalling storms over the last decade, according to a quick analysis by NCAR’s Ming Ge (see Figure 6 below).
Jeff Masters posted earlier today
on activity in the Atlantic; he’ll be back on Friday morning with our next update.
Bob HensonFigure 6.
Annual Cyclone Damage Potential (CDP) from 2000 to 2014 for typhoons across the Northwest Pacific. CDP incorporates the size and speed of motion of tropical cyclones as well as their peak sustained winds. Shown are each year's maximum CDP value for all typhoons, the average CDP for all landfalling typhoons (black), and the average CDP for all typhoons, whether or not they make landfall (blue). A longer time period would be needed to see if the apparent increase in CDP for landfalling typhoons is statistically significant. Image credit: Ming Ge and James Done, NCAR.Video 1.
Dan Lindsey (CSU/CIRA) says: “This one is too cool not to share - it's CIRA's Geocolor product from #Himawari showing #Meranti on 13-14 Sep.” Image credit: @DanLindsey77
A model moon rampages through the streets of the Chinese city of Fuzhou after being loosed by Typhoon Meranti. Image credit: Courtesy @shanghaiist