Background
In accordance with proposed changes to ICAO Annex 3, Amendment 74, the inclusion of additional METAR present weather groups needs to be allowed for, as of 0001 UTC on Wednesday 5th November 2008.
The new codes are:
SHUP (Showers of Unidentified Precipitation)
TSUP (Thunderstorm with Unidentified Precipitation)
FZUP (Freezing (or supercooled) Unidentified Precipitation
