An emergency typhoon warning is issued when a typhoon with extreme power approaches Japan. This is the first time for Japan's Meteorological Agency to issue the warning for a prefecture other than Okinawa.

When a typhoon is expected to approach to Japan, the following standards are used for issuing an emergency warning: Pressure at the storm's center is less than 930 hectopascals, or its maximum wind speed is over 180 kilometers per hour. The emergency warning applies to violent winds, storm surges and high waves.

Where typhoons often approach, such as the Okinawa, Amami and Ogasawara Island chains, the warning is issued when the pressure of the typhoon is less than 910 hectopascals, or the maximum wind speed is over 216 kilometers per hour.

An emergency heavy rain warning is issued for a region which has already experienced heavy downpours.

An emergency typhoon warning is announced for a region where the situation hasn't yet reached a critical stage, as the warning is issued 12 hours before the eye of the typhoon approaches.

In cases of record rainfall, a separate emergency heavy rain warning could be issued for a region where an emergency typhoon warning is already in effect.