Issuance criteria for weather advisories and warnings
| Advisories | Warnings | |
|---|---|---|
| Strong wind | Sustained winds of 14m/s or greater (or wind gusts of 20m/s or greater) are expected. - Mountain areas: Sustained winds of 17m/s or greater (or wind gusts of 25m/s or greater) are expected. |
Sustained winds of 21m/s or greater (or wind gusts of 26m/s or greater) are expected. - Mountain areas: Sustained winds of 24m/s or greater (or wind gusts of 30m/s or greater) are expected. |
| Wind wave | Sustained winds of 14m/s or higher are expected to persist for 3 or more hours at sea, or significant wave height is expected to reach 3 meters or higher. | Sustained winds of 21m/s or higher are expected to persist for 3 or more hours at sea, or significant wave height is expected to reach 5 meters or higher. |
| Heavy rain | 3-hour rainfall is expected to reach 60 mm or more, or 12-hour rainfall is expected to reach 110 mm or higher. | 3-hour rainfall is expected to reach 90 mm or more, or 12-hour rainfall is expected to reach 180 mm or higher. |
| Heavy Snowfall | 24-hour snowfall is expected to reach 5 cm or more. | 24-hour snowfall is expected to reach 20 cm or more. - Mountain areas: 24-hour snowfall is expected to reach 30 cm or more. |
| Dryness | Effective humidity is expected to remain at or below 35% for at least 2 consecutive days. | Effective humidity is expected to remain at or below 25% for at least 2 consecutive days. |
| Storm surge | The sea level is expected to rise and reach the locally-defined watch threshold or higher due to factors such as astronomical tides, storms, and low atmospheric pressure. | The sea level is expected to rise and reach the locally-defined warning threshold or higher due to factors such as astronomical tides, storms, and low atmospheric pressure. |
| Cold wave (Oct-Apr) |
Issued when any of the following conditions are expected: ① 1. The morning minimum temperature drops by 10℃ or more from the previous day to 3℃ or below, and is at least 3℃ below the seasonal average. ② Morning minimum temperature is –12℃ or lower for at least 2 consecutive days. ③ 1. Significant damage is expected due to a rapid drop in temperature. |
Issued when any of the following conditions are expected: ① Morning minimum temperature drops by 15℃ or more from the previous day to 3℃ or below, and is at least 3℃ below the seasonal average. ② Morning minimum temperature is –15℃ or lower for at least 2 consecutive days. ③ Widespread or severe damage is expected due to a rapid drop in temperature. |
| Typhoon | A typhoon is expected to cause conditions (winds, wind waves, rain, or storm surge) that meet their respective watch criteria. | Issued when a typhoon is expected to cause any of the following: ① 1. Strong winds, wind waves, or storm surge conditions that meet their respective warning criteria. ② 1. Total rainfall is expected to reach 200 mm or higher. |
| Asian dust | - | The hourly average PM10 concentration is expected to reach 800μg/m3 or higher and persist for at least 2 hours due to yellow dust. |
| Heatwave | The daily maximum “feels-like” temperature is expected to reach 33℃ or higher for at least 2 consecutive days. | The daily maximum “feels-like” temperature is expected to reach 35℃ or higher for at least 2 consecutive days. |