Super Typhoon Hagibis developed a separate eye and eyewall during the rapid intensification. Image / University of Wisconsin-Madison
Super Typhoon Hagibis is barrelling towards Japan after rapidly intensifying, having reorganised its inner core, known as the eyewall, where the strongest winds and heaviest rains are found.
The extraordinary display of ultrarapid intensification in Typhoon Hagibis took place on Monday, when the storm's winds increased by 100mph (160km/h) in just 24 hours, which is one of the fastest rates of intensification ever observed on Earth.
Hagibis had maximum sustained winds of up to 270km/h and stronger gusts at noon today near Chichi island in the Pacific, about 1000km off Tokyo's southern coast.
It was moving north at the speed of 20km/h and expected to weaken over cooler waters as it nears Japan's main island.
Rugby World Cup organisers have had to cancel two games scheduled for Saturday because of concerns over the anticipated impact of the typhoon.
The game between the All Blacks and Italy in Toyota has been called off as has the Pool C decider between England and France at Yokohama. Sunday's game in Yokohama between host Japan and Scotland could also be scrapped, depending on the weather.
It's the first time that games have been cancelled at rugby's showpiece tournament. All games cancelled because of weather are logged as scoreless draws and each team will get two competition points.
The Japan Meteorological Agency is warning the powerful typhoon may bring torrential rain and strong winds to central parts of the country between Saturday and Sunday, coinciding with the last round of World Cup group games.
It has urged people to take precautions to avoid potentially life-threatening danger. Airlines and train services anticipate cancellations in what is expected to be the most destructive typhoon of 2019.
According to Colorado State University hurricane researcher Philip Klotzbach, Hagibis has been a super typhoon, with maximum sustained winds of 240km/h or greater, for at least 36 hours. This is a record in the western North Pacific so far this season.
Typically, this ocean basin spawns some of the most intense tropical cyclones of any place on Earth, though storm activity has been somewhat suppressed so far this year.
The Joint Typhoon Warning Center forecasts Super Typhoon Hagibis (the name means "speed" or "velocity" in Tagalog), which has been at the equivalent intensity of a Category 5 hurricane, will begin a slow weakening trend as it curves to the northwest and eventually north.
It is expected to make a direct hit on Japan this weekend as the equivalent of a Category 1 or 2 storm.
Japan's central Pacific coast may see torrential rains beginning Friday and the high waves and tides may cause flooding.
Japan is regularly hit by Pacific storms. Typhoon Faxai caused massive power outages in Chiba prefecture near Tokyo in September. Typhoon Jebi last year killed 11 people, injured hundreds and caused an estimated US$12.6 billion (S20b) in damage. It also flooded a terminal and a runway at Kansai International Airport..
The official JTWC forecast calls for the storm to come very close to, if not making landfall, on the heavily populated island of Honshu, including Tokyo, by Sunday.
However, track forecasts are fraught with uncertainty, and the JTWC cautions that its forecast has low confidence due to a large spread in projections among the most reliable computer models.
For much of Monday into Monday night, the storm had exhibited a phenomenon associated with some of the most intense and rapidly strengthening storms on record - a pinhole eye. The JTWC measured the eye as just 5 nautical miles in diameter, but the eye has expanded as a secondary eyewall has taken over.
This has led to a bizarre sight from space, as the old, tiny eye, complete with its eyewall, spins around within the larger eye as if caught in a meteorological pinball game.
Once Hagibis undergoes a transition to an extratropical, or nontropical, low pressure system northeast of Japan and into the Bering Sea, it will help turbocharge the jet stream blowing at high altitudes from west to east across the North Pacific.
Recurving typhoons in the western Pacific are well-known for their potential to initiate significant weather pattern changes downstream, thousands of kilometres away, as the jet stream energy they provide ripples along and forms dips, or troughs, and ridges.
For example, the perturbation to the jet stream may enhance the development of a high pressure area aloft across the West, potentially bringing a period of warmer than average temperatures there.
If it seems like rapidly intensifying storms such as Super Typhoon Hagibis are occurring more regularly, it's because they are - at least in some parts of the world.
Rapidly intensifying storms are becoming more common in the North Atlantic Ocean Basin, for example. More importantly, such storms are expected to become more frequent worldwide as human-caused global warming continues.
For example, a 2017 paper that studied modelled Atlantic storms showed an uptick in the number of storms that would rapidly intensify just before landfall in a warmer world. Even more alarming was the study's simulation that storms intensifying by 70mph (112km/h) or more within 24 hours - which the author, MIT's Kerry Emanuel, found had occurred on the average of only once per century in the late 20th-century climate - may occur "every 5-10 years by the end of this century."
Another study, published last year, found that with continued global warming, more tropical cyclones will undergo rapid intensification than had done so before. It also found, using a climate model capable of simulating these massive storms amid changing atmospheric and oceanic conditions, that future storms could be so intense that a new category - Category 6, might be required to describe their intensity.
For the period between 2016 and 2035, the study found that there would be an 11 per cent uptick in major tropical cyclones, of Category 3 intensity or greater, for example. It also showed 72 storms with maximum sustained winds above 190mph (305km/h) by the end of the century, compared with just nine such storms in a simulation of the late-20th-century climate.