6 3 2017-09-15T15:45:38.696Z Code Table 4678: Significant weather phenomena This register provides terms that may be used to describe significant [recent], present and forecast weather - enumerating the set of meteorologically valid options defined in WMO No. 306 Vol 1 code-table 4678. Each term comprises one or more of the elements from code-table 4678: 'intensity or proximity', 'descriptor', 'precipitation', 'obscuration' and 'other'. w'w' 306 306: Significant Weather 2024-03-27T15:06:26.267Z WMO No. 306 Manual on Codes: Significant Weather.