Japan's weather officials predict warmer-than-normal temperatures and less snow across the country in its three-month-period forecast of December through February.
The Meteorological Agency on Tuesday released the forecast. It says it is expecting a generally warm winter, but caution is needed for heavy snow brought by a cold air mass that may temporarily flow into the country.
Forecasters say the westerlies are expected to deviate more northward than in normal years. This will tend to prevent cold air mass from flowing over eastern and western Japan, as well as the Okinawa and Amami regions.
They project average temperatures through the three months to be higher than usual in these regions, and normal or higher in northern Japan.
The agency also forecasts light snowfall in the Japan Sea side of eastern and western Japan. It expects an average or less-than-average snowfall in the Japan Sea side of northern Japan.
Officials predict average or above-average precipitation in western Japan, the Okinawa and Amami regions, and in the Pacific side of eastern Japan. They say precipitation in northern Japan and the Japan Sea side of eastern Japan will likely be about average.
The agency says the northward moves of the westerlies will be due to warmer-than-normal ocean surface temperatures near the equator off Peru and in the western Indian Ocean.
The agency forecasts a warmer winter nationwide, but it also says temporary influx of cold air mass could prompt the development of snow clouds in northern Japan.
It also projects a more-than-normal number of low pressure systems will pass along the Pacific coast, which often bring heavy snow to the Pacific side, including Tokyo and the rest of the Kanto region, in the season.