When Tropical Storm Nepartak formed 1,800 kilometers from Tokyo in the Pacific on Friday, its projected course toward the capital had some wondering if the Olympic Games were in for yet another setback.

Instead, the storm lingered just off the coast, moving north and then making history with a landfall in Miyagi Prefecture on Wednesday morning. That marked the first landfall of a tropical storm in the prefecture since records began in 1951. And according to typhoon expert Robert Speta, that wasn’t the only unusual thing about Nepartak.

“Dating back to when typhoon tracking records began, there has never been a landfalling storm north of Tokyo in July,” Speta said Wednesday.

The last time a tropical storm reached Japan’s northeastern coast was Aug. 30, 2016, when one hit Iwate Prefecture.

Nepartak is also the first tropical storm or typhoon to make landfall in Japan since October 2019.

The storm made landfall in an area near the city of Ishinomaki shortly before 6 a.m. Wednesday, according to the Meteorological Agency.

Its trip from east to west and then north is not the standard route for tropical storms or typhoons at any time of the year.

“Typically we don’t see storms this far north for a few reasons,” Speta said. “One is the sea surface temperatures are often too cold to support tropical systems. Another is wind shear typically rips them apart.

“With Nepartak, it was cradled in an upper level low (pressure system) … thus keeping much of the tropical dissolving wind shear off of it.”

A rainbow at the Odaiba Marine Park in Tokyo on Tuesday as Tropical Storm Nepartak passed off the coast | AFP-JIJI
A rainbow at the Odaiba Marine Park in Tokyo on Tuesday as Tropical Storm Nepartak passed off the coast | AFP-JIJI

Speta said the unusual path was a result of a monsoonal gyre that is currently dominating the western Pacific, something he’s only seen a few times in his more than a decade of covering storms.

Olympic organizers had been watching the storm’s path closely, and some events had been rescheduled to avoid any potential deluge. But in the end, it was the surfing competition that likely saw the biggest impact, with higher waves offering a splashier show.

As of noon Wednesday, the storm was traveling north over Iwate Prefecture, packing winds of up to 65 kph and gusts of up to 90 kph, the Meteorological Agency said. Its forecast showed the storm moving west over Akita Prefect and into the Sea of Japan by Wednesday evening before weakening into an extratropical cyclone. The storm is forecast to bring rainfall of up to 100 millimeters in the northeastern region over the next 24 hours.

Looking ahead, Speta said Japan and the region could be in for a late typhoon season.

“There is a La Nina watch in place much like last year. This means sea surface temperatures across the western Pacific will stay above average and thus (offer) more fuel for some late season storms,” he said, “especially for southwestern Japan and into the Philippines.”

Information from Kyodo added

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