Japan's Meteorological Agency says large and powerful Typhoon Hinnamnor is heading north off Kume Island in Okinawa Prefecture. The prefecture is believed to be out of the storm zone.
The typhoon is forecast to develop and change its course eastward to approach Kyushu on Tuesday.
Moist air from the typhoon and a rain front extending from the Korean Peninsula to the Sea of Japan are likely to keep atmospheric conditions unstable in Kyushu and regions away from the typhoon. Weather officials are forecasting localized downpours.
Rainfall in the 24-hour period through late Monday afternoon could reach 180 millimeters in southern Kyushu and Shikoku; 150 millimeters in the Amami region and Tokai; and 120 millimeters in northern Kyushu.
Strong winds are forecast, mainly in Kyushu, from Monday to Tuesday.
The maximum wind speed is expected to reach 90 kilometers per hour in northern Kyushu, 83 kilometers per hour in southern Kyushu and 72 kilometers per hour in Amami.
Powerful winds are forecast in northern Kyushu on Tuesday, with a maximum instantaneous wind velocity of 144 to 216 kilometers per hour.
Weather officials are urging caution against mudslides, flooding in low-lying areas, swelling rivers, gusty winds, high waves as well as lightning strikes and tornadoes.