Tokyo may get a late-season hit from Hagibis
Strong typhoons do not typically threaten central Japan as late as mid-October, but Hagibis is an unusual storm. Forecast models are in close agreement on a classic recurving path that will bring the hurricane close to the Tokyo Bay region of Honshu island between Saturday and Sunday local time. The spread among models is more in timing than in track. Because of the angle of approach, though, only a slight shift left or right could result in either a high-impact Tokyo Bay landfall or a glancing brush offshore.

Hagibis is likely to be slow to weaken. The atmosphere around the typhoon will remain moist (mid-level relative humidity around 60%). Sea surface temperatures will gradually drop along the typhoon’s path from the very warm current values of around 30°C (86°F) to around 27°C (81°F) as the storm nears Honshu, which is still more than warm enough to support a typhoon. Wind shear will increase from light to moderate values (5 – 10 knots) to a strong 20 knots by this weekend, with a more dramatic increase after Hagibis reaches Japan. At first, some of this shear may be in the form of midlatitude flow on the north side of Hagibis that could help ventilate the storm. If Hagibis becomes a truly annular storm, that will slow the pace of weakening as well. Even so, Hagibis will be a considerably less potent storm than it is now by the time it nears Japan on Saturday (U.S. EDT).

The Joint Typhoon Warning Center predicted on Wednesday that the core of Hagibis will move over or near Tokyo Bay around 8 am EDT Saturday as a Category 2 typhoon. This is roughly comparable to the strength of Faxai, which struck Tokyo Bay as a Category 2 typhoon last month, damaging more than 20,000 structures and inflicting as much as $9 billion in damage. One major difference is that Hagibis will be a larger, more long-lived, and more powerful typhoon than Faxai as it approaches Japan, so Hagibis could pack more widespread impacts—including a more significant threat of storm surge—depending on its ultimate trajectory and strength.

Hagibis could affect the Rugby World Cup taking place this month in several sites in Japan. World Rugby will hold a press conference at 11 pm EDT Wednesday to discuss the storm and any needed actions, according to BBC.

[link to www.wunderground.com (secure)]