Table B-1. Descriptive terms for present weather (extracted from WMO Code 4677) 



Code figure 

 00 



if 01 



l| I 



I I 02 

 ^^°- 03 

 04 

 05 

 06 



07 



08 



09 



10 

 11 

 12 



13 

 14 

 15 



16 



17 



18 



19 



20 



21 



22 



23 



24 



25 



26 



27 



28 



29 



30] 



31 



32] 



33 



34 



35 



36 



37 



38 



39 



40 



41 

 42 

 43 

 44 

 45 

 46 

 47 

 48 

 49 



characteristic change of the state of slty during the 

 past hour 



Cloud development not observed or not ob- 

 servable 



Clouds generally dissolving or becoming less de- 

 veloped 



State of sky on the whole unchanged 



Clouds generally forming or developing 



Visibility reduced by smoke, e.g. veldt or forest fires, industrial smoke or volcanic ashes 



Haze 



Widespread dust in suspension in the air, not raised by wind at or near the station at the time of obser- 

 vation 



Dust or sand raised by wind at or near the station at the time of observation, but no well developed dust 

 whirl(s) or sand whirl(s), and no duststorm or sandstorm seen 



Well developed dust whirl(s) or sand whirl(s) seen at or near the station during preceding hour or at the 



time of observation, but no duststorm or sandstorm 

 Duststorm or sandstorm whithin sight at the time of observation or at the station during the preceding 

 hour 



Mist 



Patches of 1 shallow or ice fog at the station, whether on land 



More or less f o'" sea, not deeper than about 2 metres on land or 10 



continuous I metres at sea 



Lightning visible, no thunder heard 



Precipitation within sight, not reaching the ground or the surface of the sea 



Precipitation within sight, reaching the ground or the surface of the sea, but distant (i.e. estimated to be 

 more than 5 km) from the station 



Precipitation within sight, reaching the ground or the surface of the sea, near to, but not at the station 



Thunder storm, but no precipitation at the station 



Squalls 



Funnel cloud(s)*) 



Drizzle (not freezing) or snow grains 



Rain (not freezing) 



Snow 



Rain and snow or ice pellets, type (a) (sleet) 



Freezing drizzle or freezing rain 



Shower(s) or rain 



Shower(s) of snow, or of rain and snow 



Shower(s) of hail,** or of rain and hail** 



Fog or ice fog 



Thunderstorm (with or without precipitation) 



at or within sight of the station during the preceding 

 hour or at the time of observation 



not falling as shower(s) 



Slight or moderate duststorm or sandstorm 



Severe duststorm or sandstorm 



has decreased during the preceding hour 



no appreciable change during the preceding hour 



has begun or has increased during the preceding hour 



Ihas decreased during the preceding hour 

 no appreciable change during the preceding hour 

 has begun or has increased during the preceding hour 

 Slight or moderate drifting snow 

 Heavy drifting snow 

 Slight or moderate drifting snow 

 Heavy drifting snow 

 Fog or ice fog at a distance at the time of observation, but not at the station during the preceding hour, 



the fog or ice fog extending to a level above that of the observer 

 Fog or ice fog in patches 



has become thinner during the preceding hour 



generally low (below eye level) 

 generally high (above eye level) 



Fog or ice fog, sky visible 

 Fog or ice fog, sky invisible 

 Fog or ice fog, sky visible 

 Fog or ice fog, sky invisible 

 Fog or ice fog, sky visible 

 Fog or ice fog, sky invisible 

 Fog, depositing rime, sky visible 

 Fog, depositing rime, sky invisible 



no appreciable change during the preceding hour 

 has begun or has become thicker during the preceding 



B-2 



Change 1—1970 



