Abstract
A new river discharge predicting system all over Japan utilizingJapan Meteorological Agency's Meso-scale model Grid Point Value (MSM-GPV) datasets isdeveloped. The system, “Today's Japan, ” consistsof a land surfacemodel Iso-MATSIRO and a river routing scheme J-TRIP. An Web browser-based visualization interface is also included. This paper presents structure of the system, and manipulates hindcasts for2003 and 2004 andverifies them by using observed discharge data. The results indicate that the systemis robust enough and acceptable for reproducing big flush floods and snowmelt floods, but also find some significant underestimates and shortcomings of reproducing low-flows.