- Heavy Rain (yellow)
- Extremely Heavy Rain (orange)
- Torrential Rain (red)
- Extremely Torrential Rain (purple)
update: It's been pointed out that there is a "descriptions tab" on the page which says:
- Heavy Rain: 24-hour accumulated rainfall exceeds 80 millimeters, or 1-hour rainfall exceeds 40 millimeters.
- Extremely Heavy Rain: 24-hour accumulated rainfall exceeds 200 millimeters, or 3-hour accumulated rainfall exceeds 100 millimeters.
- Torrential Rain: 24-hour accumulated rainfall exceeds 350 millimeters, or 3-hour accumulated rainfall exceeds 200 millimeters.
- Extremely Torrential Rain: 24-hour accumulated rainfall exceeds 500 millimeters.
I'm curious if these four descriptions are standardized categories or are simply chosen here to give a sense of increasingness to the progression in color and severity of rainfall.
So I'd like to ask:
Are terms like "Extremely Torrential Rain" universal in meteorology? Are these standardized categories widely used in meteorology or are these ad hoc definitions for this weather service?
Screenshot from https://www.cwb.gov.tw/V8/E/P/Warning/W26.html circa
01:30 07-Aug-2021 UTC