Japanese weather officials have issued a heavy rain emergency warning for Niigata Prefecture in addition to neighboring Yamagata Prefecture. The level 5 alert is the highest. People are advised to exercise great caution.

Niigata is experiencing the heaviest rainfall in decades. It's highly likely serious disasters such as flooding and landslides have already occurred.

Heavy rain since Wednesday has already brought an emergency warning to Yamagata in northern Japan. Torrential rain is continuing in some areas.

The Meteorological Agency is calling on people to check their surroundings and do whatever necessary to protect their lives. That includes moving to a strong building nearby or the second floor or higher of a building opposite a cliff or slope if it's dangerous to go outside.

Kurora Ryuta of the Japan Meteorological Agency spoke at a news conference. He said, "It is necessary to exercise maximum caution even in places where disasters are not usually thought to occur. People are advised to follow evacuation information issued by local governments and secure their safety immediately to protect their lives and the lives of their loved ones."

Weather officials say warm and humid air is blowing toward a front over northern and central Japan, making the atmosphere extremely unstable.