Packing winds of 150 mph, Hagibis, the behemoth super typhoon crashing through the northwest Pacific, could impact Japan as the equivalent of a Category 1 or 2 hurricane this weekend.

Tokyo, home to more than 9 million people, is preparing for wind gusts approaching 100 mph; the system is predicted to make landfall somewhere in Japan on Saturday. Hagibis — whose name is a Filipino word meaning “velocity” or “swiftness” — has been at super-typhoon strength for three straight days.

On Monday, the world watched as Hagibis intensified at one of the strongest clips on record, metastasizing from a tropical storm to the equivalent of a Category 5 in a day’s time. That marked a 90 mph jump in just 18 hours — more than three times the rate a storm would have to strengthen to meet the criteria for “rapid intensification.” It is the fastest jump in strength of any storm in that part of the world in more than 20 years, and probably one of the fastest intensification rates on record worldwide.

Hagibis put on an epic display for weather satellites as it got its act together, a tiny pinhole eye just five miles across emerging Sunday night. On Tuesday, Hagibis wavered some after brushing past the Mariana Islands, an eyewall replacement cycle knocking Hagibis back to Category 4 strength. Hours later, a new eye developed, and Hagibis reclaimed Category 5 status.

In a bizarre unfolding of events, Hagibis’s new eye absorbed the old eye as well as the eyewall, the zone of extreme winds surrounding the storm center. For a while, the beastly storm’s initial five-mile-wide eye, enshrouded by a remnant eyewall, was spinning inside the newly formed 25-mile-wide eye. It may be the first time high-resolution weather satellites captured such a bizarre eyewall replacement cycle with such resolution.

By Wednesday, Hagibis was once again a Category 5 monster, its clear eye eerily staring at satellites 22,000 miles in space.

Hagibis is about 600 miles away from Japan, moving north-northwest at 12 mph. A warming of cloud tops, suggestive of less-vigorously-rising air, was visible on satellite Thursday afternoon, perhaps the first signs of Hagibis’s inevitable weakening. While it no longer can be a super typhoon, the storm will remain powerful when it arrives in or near Japan on Saturday, aimed precariously close to Tokyo.

Every prefecture along Japan’s south-facing coastline is under a high-wave advisory; additional warnings are likely to be issued as Hagibis’s exact track becomes more certain. The Joint Typhoon Warning Center is calling for a 100 mph eyewall passage near or directly over Toyko very early Saturday morning. The Japanese Meteorological Agency is forecasting much of Japan to be subjected to winds of 60 mph or greater. Torrential rainfall and areas of flooding are also risks.

However, there is enormous uncertainty with this forecast, even just two days out. Subtle shifts of 15 or 20 miles could push the eyewall, the zone of strongest winds, farther inland or keep it offshore entirely if Hagibis turns toward the northeast sooner than anticipated. These small shifts will have huge implications for how severely the storm affects specific areas. The harshest impacts will be confined mostly to the eyewall, which by then will be about 40 to 50 miles across at most.

Regardless of the ultimate track, the anticipated impacts are already manifesting themselves in the form of event cancellations and travel disruptions. Two Rugby World Cup matches that were originally slated for this weekend have since been canceled, according to the BBC. Japan Air Lines, ANA, Jetstar Japan and a number of other airlines into Tokyo have announced cancellations.

Down the road, Hagibis will become extratropical sometime Monday into Tuesday, its energy being absorbed into and intensifying a wave in the jet stream. That energy could bring active weather to the western United States toward the end of next week.