(1) If the south coast low pressure moves north from Hachijojima, the Kanto area will be covered by the low pressure rainfall area and warm air will flow in. Therefore, what falls is likely to be rain instead of snow.
(2) If the south coast cyclone moves slightly south of Hachijojima, it will draw cold air from the north while rain covers the Kanto region. So, it snows easily, and sometimes it snows heavily.
(3) If the south coast cyclone moves south of Hachijojima, the precipitation area itself does not reach the Kanto land, and in many cases neither snow nor rain falls. However, as cold air moves south, clouds tend to spread in the Kanto region.
The path of the south coast cyclone and the location of Hachijojima is one of the criteria for forecasting snow in the Kanto region, but it is not the only decisive factor. Whether or not there will be heavy snow in the Kanto region depends on factors such as the degree of development of the low pressure system, the speed at which it develops, the drop in temperature, and the inflow of moist air. (Even if it rains like ①, if it rains harder, the air around it will cool and turn into snow.)
People in the Kanto region are usually not used to snow, so check the latest weather forecast often, and if snow is expected, take precautions as soon as possible.
