BR Mist #1
PL Ice pellets
DS Duststorm
PO Dust/sand whirls (dust devils)
DU Dust (widespread)
RA Rain
DZ Drizzle
SA Sand
FC Funnel cloud (tornado or waterspout)
SG Snow grains
FG Fog #2
SN Snow
FU Smoke
SQ Squall
GR Hail (ø ≥5mm)
SS Sandstorm
GS Small hail and/or snow pellets
UP Unknown precipitation
HZ Haze
VA Volcanic ash
IC Ice crystals #3
#1 VIS at least 1000m but not more than 5000m
#2 VIS less than 1000m, except when qualified by MI, BC, PR or VC
#3 VIS 5000m or less
Characteristics of Weather Phenomena
BC Patches
MI Shallow
BL Blowing
PR Partial
DR Low drifting
SH Shower
FZ Freezing
TS Thunderstorm
Source: ICAO
See also:
Meteorological Aeronautical Report (METAR)
Terminal Aerodrome Forecast (TAF)
Types and Characteristics of Weather Phenomena