Types of Precipitation?

今日又溫下書…到底有咩類型既precipitation?

首先， what’s precipitation?

根據FAA PHAK chapter 12 (天氣果課書）：

Precipitation refers to any type of water particles that form in the atmosphere and fall to the ground. 

睇返之前 收集既一個wmo網頁，天氣現象大致分為：水、光、電、塵相關

而同水有關既可以睇呢個網：

https://cloudatlas.wmo.int/en/hydrometeors.html

Precipitation 係指 11類 falling particles

(b) Falling particles (precipitation)

1. Rain : water droplets, but not drizzle

2. Supercooled rain : water droplets, but not drizzle, and below 0 °C

3. Drizzle : very fine drops of water (diameter of usually less than 0.5 mm) ; related to  Stratus and ground fog

4. Supercooled drizzle : very fine drops of water (diameter of usually less than 0.5 mm) , and below 0 °C

5. Snow : ice crystals ; usually temperatures warmer than about –5 °C

6. Snow grains : very small opaque white particles of ice  (diameter is generally less than 1 mm) ; temperature approximately 0 °C and –10 °C ; related to Stratus and ground fog

7. Snow pellets :  generally conical or rounded (diameter may be as large as 5 mm) ; related to  Cumulus or Cumulonimbus

8. Small hail : not easily crushable; when it falls on hard ground it bounces with an audible sound on impact ; intermediate stage between the snow pellet and the hailstone ; related to Cumulonimbus 

9.  Hail : “ice ball” (conical or irregular in form) ; generally 5−50 mm in diameter ; related to heavy thunderstorms

10. Ice pellets : not easily crushable ; diameter is less than 5 mm ; related to  Altostratus or Nimbostratus

11. Diamond dust : usually found in polar and alpine regions and continental interiors, especially in clear, calm and cold weather ;  where temperatures less than –10 °C in a rapidly cooling airmass ; diameters about 100 μm ; related to halo phenomena 

再簡單D，可以咁理解

1. Rain / Freezing rain
2. Drizzle / Freezing drizzle
3. Snow / Snow Grains / Snow Pellets
4. Hail / Small hail
5. Ice pellets
6. Diamond dust