October 14, 2025 Results of Demonstration Experiments on Providing "Highly Accurate Weather Forecast Information" at the Expo 2025 Osaka, Kansai, Japan

　To accurately observe and forecast heavy rainfall at the Expo 2025 Osaka, Kansai, Japan, demonstration experiments were conducted to provide "highly accurate weather forecast information" using next-generation weather radar developed by the Ministry of Internal Affairs and Communications (MIC), the National Institute of Information and Communications Technology (NICT), and other organizations.
Information on rain cloud conditions and other weather data was successfully distributed to smartphone applications of Japan Association for the 2025 World Exposition, visitors, and others via push notifications. Information on rain cloud conditions and other weather data was successfully distributed to the smartphone applications of exposition associations, visitors, and others via push notifications.

Note: The published materials are in Japanese only.

1. Overview

　The MIC and NICT played a central role in developing a next-generation weather radar called the Multi-Parameter Phased Array Weather Radar (MP-PAWR). At the Expo 2025 Osaka, Kansai, Japan, this radar was used in demonstration experiments to provide highly accurate weather forecast information to the Japan Association for the 2025 World Exposition, visitors, and others. The experiments were primarily conducted by NICT and other implementing entities in collaboration with industry, government, and academia.
　Throughout the Expo period, highly accurate observations and forecasts of heavy rainfall in and around the Expo venue were made to distribute advance push notifications of heavy rainfall and 3D visualizations of rain clouds to smartphone applications.
In particular, during the period from August 5 to August 31, the supercomputer "Fugaku" was used to distribute forecasts up to approximately 25 minutes in advance to the website of the Institute of Physical and Chemical Research (RIKEN), as well as via smartphone applications.

< Implementing entities >
・NICT, RIKEN, National Research Institute for Earth Science and Disaster Resilience (NIED), The University of Osaka, Preferred Networks, Inc., MTI Ltd.

2. Future plans

　We plan to continue analyzing and verifying the observation and forecast data obtained through the demonstration experiments. Aiming to build a disaster-resilient society, we will collaborate with relevant organizations to advance observation and forecasting technologies for torrential rainfall and other extreme weather conditions using the next-generation weather radar, MP-PAWR.