The Japan Meteorological Agency made significant changes to its disaster prevention weather information at the end of May. The purpose of the improvements is to encourage residents to evacuate. Since this is crucial information for saving lives, the changes will be explained in several parts. The previous information was cluttered and difficult to understand. This time, the agency held repeated discussions with experts and organized the information to make it clearer. The new disaster prevention weather information is designed so that when a warning is issued, people can understand what evacuation actions they should take.

Figure 1 shows the new “disaster prevention weather information.” It is divided into five levels for “rivers,” “heavy rain,” “landslides,” and “storm surges” (warnings not listed in this table remain unchanged).

Each is linked to a “warning level that conveys evacuation actions,” and the name is preceded by “Level ○.”

Level 5 Special Warning: Emergency Safety Measures
Level 4 Danger Warning: Evacuation Order
Level 3 Warning: Evacuation for the Elderly, etc.
The level indicates the evacuation actions we must take.

Figure 2 shows the previous disaster prevention weather information. There was a “Flood Warning Information” corresponding to Level 3 of flood forecasts, and a “Landslide Warning Information” corresponding to Level 4 of landslide disasters.

Despite both being called “warning information,” they were at different levels. Additionally, there was no Level 4 equivalent warning for flood damage or heavy rain inundation damage. The inconsistencies and gaps in these names have been resolved, making the system clearer.

Consequently, a new “Level 4 Danger Warning” has been introduced between “Level 3 Warning” and “Level 5 Special Warning.” The types of warnings have also been reviewed. This will be explained in subsequent parts.

As can be seen from Figure 1, the information is now clearer and easier to understand.

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Disaster prevention knowledge and wisdom learned from covering disaster areas and working as an NPO researcher will be shared in a column format.

Japan Meteorological Agency

The Japan Meteorological Agency (JMA) is the government body responsible for collecting and reporting weather data, issuing forecasts, and monitoring seismic and volcanic activity across Japan. Established in 1875, it has a long history of advancing meteorological science, including the development of the country’s early warning systems for natural disasters like earthquakes and tsunamis. Today, the JMA is crucial for public safety and economic planning, providing essential information to mitigate the impacts of Japan’s frequent natural hazards.

Flood Warning Information

The “Flood Warning Information” system is not a single physical place but a network of monitoring stations, data centers, and communication channels used to alert communities about potential flooding. Its history traces back to early river gauges and telegraph systems in the 19th century, evolving with modern radar, satellite technology, and real-time data sharing to save lives and property. Today, it is a critical component of disaster preparedness, operated by agencies like the National Weather Service to provide timely warnings and updates.

Landslide Warning Information

“Landslide Warning Information” refers to systems and data that monitor ground movement, rainfall, and soil conditions to predict and alert communities about potential landslides. These warnings are crucial for public safety in mountainous or unstable terrains, often managed by geological surveys or meteorological agencies. Historically, such systems have evolved from basic observation to advanced sensor networks and real-time communication, especially after major landslide disasters.