Moisture from former Typhoon Mekkhala combined with a rapidly strengthening area of low pressure to the south of Japan will result in a period of heavy rain for eastern Japan on Thursday.
The Greater Tokyo Area will experience some of the heaviest rain as the storm quickly tracks to the northeast just off the coast of Japan.
Heavy rain will fall across Shikoku and southern Honshu late Wednesday night into Thursday morning before shifting northward into eastern Honshu.
Heavy rain Thursday afternoon will quickly taper off to some light rain and drizzle Thursday evening around Tokyo.
Mild air being pulled northward with this storm will result in snow only falling across the highest elevations of Honshu on Thursday.
As the storm lifts farther north on Friday, blizzard conditions are expected across eastern Hokkaido while colder air wrapping in behind the storm will result in widespread rain and snow showers across western Honshu with snow squalls in parts of northern Honshu and western Hokkaido.
Weak high pressure will foster largely dry weather across Japan for the weekend.