Rain is expected to intensify again across a wide area of southern Kanto through the early morning of 12 August, with thunderstorms, graupel and hail possible in some locations. The centre of Typhoon No. 15 is forecast to move eastward gradually after midnight, but moist air is expected to continue flowing into eastern Japan even after the storm itself moves away. Forecasters said the unusual track of the typhoon, which has been moving from east to west, could allow humid air to persist behind the system. Typhoons that move from west to east are often followed by drier air and improving weather, but in this case rainfall could continue after the centre has passed. Accumulated rainfall over the following 48 hours is expected to increase particularly along the Pacific side of Tohoku and in the Kanto region, raising the risk of further heavy rain.