Disaster Mitigation in Japan-Weather Information
The Japan Meteorological Agency is the best source in various languages for local weather and for real-time risks evaluation. In addition to weather forecasts, its English Home Page offers weather warnings/advisories, real-time risk maps for landslides, inundations and floods, tropical cyclones information, tsunami warnings and advisory, earthquake information and volcanic warning/forecasts.
As you can see in the following screen capture of a map available on July 3rd at 19:10, the level of precision can be very high. Similar maps are available for all the risks above-mentioned.
In addition, municipalities exposed to flooding such as Toride in Ibaraki have their own disaster prevention measures. Be prepared!