Japan: Japan will switch to a revamped weather warning system Thursday, ahead of the country's rainy and typhoon seasons. The Japan Meteorological Agency and the land ministry will introduce the improved system featuring five alert levels for flooding, heavy rain, landslides, and storm surges.

According to Philippines News Agency, an emergency warning will be issued for a natural disaster that may have already occurred, prompting municipalities to declare a Level 5 situation and issue an order urging residents to take emergency action to protect themselves. A danger warning, a newly established category, will be announced for a Level 4 situation, prompting municipalities to instruct residents to evacuate. For a Level 3 situation, a regular warning will be issued, leading to an evacuation order for elderly and other vulnerable people.

The system will also issue an advisory for a Level 2 situation and early warning information for a Level 1 situation, covering potential disasters that may occur over the next five days. Flooding alerts will encompass 400 large rivers across Japan, with an urgent warning newly added to the list of warnings and alerts.

Heavy rain alerts will focus on flooding of smaller rivers, while landslide alerts will caution against landslides on steep slopes and debris flows. Storm surges, defined as rises in sea level caused by decreased atmospheric pressure and strong winds from typhoons, will be included in the warnings. These surges can lead to prolonged flooding in coastal areas, exacerbated by high tides.

The new system will initially implement wave run-up height evaluations in alerts for Kurobe, and the towns of Nyuzen and Asahi in the Toyama prefecture. These areas were significantly impacted by a 2008 tsunami. Over time, this feature will expand to cover other regions. To address disaster risks heightened by a linear precipitation zone, the agency will also offer two- to three-hour forecasts for smaller areas in addition to its 12-hour forecast.