WMO Meteorological codes

This document gives details of the Meteorological codes for use at observing stations. Full WMO code documentation is available from the WMO website.


Indicator for source and units of wind speed.

WMO code 1855:Indicator for source and units of wind speed. 

0   Wind speed estimated (m/s).
1   Wind speed obtained from anemometer (m/s).
3   Wind speed estimated (knots).
4   Wind speed obtained from anemometer (knots).


Concentration or arrangement of sea ice (Ice Formation ID)

WMO code 0639:Concentration or arrangement of sea ice.           

0   No sea ice in sight
1   Ship in open lead more than 1.0 nautical mile wide, or ship in fast ice with boundary beyond limit of visibility
2   Sea ice present in concentrations less than 3/10 (3/8), open water or very open pack ice - Sea ice concentration is uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
3   4/10 to 6/10 (3/8 to less than 6/8), open pack ice - Sea ice concentration is uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
4   7/10 to 8/10 (6/8 to less than 7/8), close pack ice - Sea ice concentration is uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
5   9/10 or more, but not 10/10 (7/8 to less than 8/8), very close pack ice - Sea ice concentration is uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
6   Strips and patches of pack ice with open water between - Sea ice concentration is not uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
7   Strips and patches of close or very close pack ice with areas of lesser concentration between - Sea ice concentration is not uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
8   Fast ice with open water, very open or open pack ice to seaward of the ice boundary - Sea ice concentration is not uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
9   Fast ice with close or very close pack ice to seaward of the ice boundary - Sea ice concentration is not uniform in the observation area - Ship in ice or within 0.5 nautical mile of ice edge
/   Unable to report, because of darkness, lack of visibility, or because ship is more than 0.5 nautical mile away from ice edge


Stage of Ice development (Ice Age ID)

WMO code 3739:Stage of ice development.           

0   New ice only (frazil ice, grease ice, slush, shuga)
1   Nilas or ice rind, less than 10 cm thick
2   Young ice (grey ice, grey-white ice), 10-30 cm thick
3   Predominantly new and/or young ice with some first-year ice
4   Predominantly thin first-year ice with some new and/or young ice
5   All thin first-year ice (30 - 70 cm thick)
6   Predominantly medium first-year ice (70 - 120 cm thick) and thick first-year ice (>120 cm thick) with some thinner (younger) first-year ice
7   All medium and thick first-year ice
8   Predominantly medium and thick first-year ice with some old ice (usually more than 2 metres thick)
9   Predominantly old ice
/   Unable to report, because of darkness, lack of visibility or because only ice of land origin is visible or because ship is more than 0.5 nautical mile away 


Ice of Land Origin (Land Ice Type ID)

WMO code 0439:Ice of Land Origin.           

0   No ice of land origin
1   1-5 icebergs, no growlers or bergy bits
2   6-10 icebergs, no growlers or bergy bits
3   11-20 icebergs, no growlers or bergy bits
4   Up to and including 10 growlers and bergy bits - no icebergs
5   More than 10 growlers and bergy bits - no icebergs
6   1-5 icebergs, with growlers and bergy bits
7   6-10 icebergs, with growlers and bergy bits
8   11-20 icebergs, with growlers and bergy bits
9   More than 20 icebergs, with growlers and bergy bits - a major hazard to navigation
/   Unable to report, because of darkness, lack of visibility or because only sea ice is visible


True bearing of principal ice edge (Ice Edge ID)

WMO code 0739:True bearing of principal ice edge           

0   Ship in shore or flaw lead
1   Principal ice edge towards NE
2   Principal ice edge towards E
3   Principal ice edge towards SE
4   Principal ice edge towards S
5   Principal ice edge towards SW
6   Principal ice edge towards W
7   Principal ice edge towards NW
8   Principal ice edge towards N
9   Not determined (ship in ice)
/   Unable to report, because of darkness, lack of visibility or because only ice of land origin is visible


Present ice situation and trend of conditions over the preceding 3 hours (ice_cond_trnd)

WMO code 5239: Present ice situation and trend of conditions over the preceding 3 hours

0   Ship in open water with floating ice in sight
1   Ship in easily penetrable ice; conditions improving - Ship in ice
2   Ship in easily penetrable ice; conditions not changing - Ship in ice
3   Ship in easily penetrable ice; conditions worsening - Ship in ice
4   Ship in ice difficult to penetrate; conditions improving - Ship in ice
5   Ship in ice difficult to penetrate; conditions not changing - Ship in ice
6   Ice forming and floes freezing together - Ship in ice difficult to penetrate and conditions worsening - Ship in ice
7   Ice under slight pressure - Ship in ice difficult to penetrate and conditions worsening - Ship in ice
8   Ice under moderate or severe pressure - Ship in ice difficult to penetrate and conditions worsening - Ship in ice
9   Ship beset - Ship in ice difficult to penetrate and conditions worsening - Ship in ice
/   Unable to report, because of darkness or lack of visibility


Rate of ice accretion on ships (Ice accretion rate code)

WMO code 3551: Rate of ice accretion on ships

0   Ice not building up
1   Ice building up slowly
2   Ice building up rapidly
3   Ice melting or breaking up slowly
4   Ice melting or breaking up rapidly


Ice accretion on ships (Ice accretion type)

WMO code 1751: Ice accretion on ships

1   Icing from ocean spray
2   Icing from fog
3   Icing from spray and fog
4   Icing from rain
5   Icing from spray and rain


Type / Genus of cloud:

WMO code 0500: Genus of cloud         

/ - cloud not visible owing to darkness, fog, duststorm, sandstorm or other 
    analogous phenomena                                               
0 - cirrus  (CI)                                                            
1 - cirricumulus (CC)                                                       
2 - cirrostratus (CS)                                                       
3 - altocumulus (AC)                                                        
4 - altostratus (AS)                                                        
5 - nimbostratus (NS)                                                       
6 - stratocumulus (SC)                                                      
7 - stratus (ST)                                                            
8 - cumulus (CU)                                                            
9 - cumulonimbus (CB)                                                     


High cloud type:

WMO code 0509:Clouds of genera Cirrus, Cirrocumulus and Cirrostratus.           

/ - cirrus, cirrocumulus & cirrostratus invisible owing to darkness, fog, blowing 
    dust or sand, or other phenomena, or more often because of the presence of a 
    continuous layer of lower clouds           
0 - no cirrus, cirrocumulus or cirrostratus clouds                          
1 - cirrus in the form of filaments, strands or hooks, not progressively invading
    the sky.                                     
2 - dense cirrus, in patches or entangled sheaves, which usually do not increase 
    & sometimes seem to be the remains of the upper part of a cumulonimbus; or 
    cirrus with sproutings in the form of small turrets; or cirrus having the 
    appearance of cumuliform tufts            
3 - dense cirrus, often in the form of an anvil, being the remains of the upper 
    part of cumulonimbus                                          
4 - cirrus in the form of hooks, filaments, or both, progressively invading the 
    sky; they generally become denser as a whole.              
5 - cirrus (often in bands converging towards 1 point or 2 opposite points of 
    the horizon) and cirrostratus, or cirrostratus alone;in either case, they 
    are progressively invading the sky, and generally growing denser as a whole, 
    but the continuous veil does not reach 45 degrees above the horizon.                                 
6 - cirrus (often in bands converging towards 1 point or 2 opposite points of 
    the horizon) and cirrostratus, or cirrostratus alone;in either case, they 
    are progressively invading the sky, and generally growing denser as a whole; 
    the continuous veil extends more than 45 degrees above the horizon, without 
    the sky being totally covered.                                                        
7 - veil of cirrostratus covering the celestial dome                        
8 - cirrostratus not progressively invading the sky and not completely covering 
    the celestial dome.                                 
9 - cirrocumulus alone, or cirrocumulus accompanied by cirrus or cirrostratus, or 
    both, but cirrocumulus is predominant                


Low cloud type:

WMO code 0513: Clouds of genera Stratocumulus, Stratus, Cumulus, etc.         

/ - stratocumulus, stratus, cumulus and cumulonimbus invisible owing to darkness, 
    fog, blowing dust or sand, or other phenomena              
0 - no stratocumulus, stratus, cumulus or cumulonimbus                      
1 - cumulus with little vertical extent and seemingly flattened, or ragged 
    cumulus, other than of bad weather, or both                      
2 - cumulus of moderate or strong vertical extent, generally with protuberances 
    in the form of domes or towers, either accompanied or not by other cumulus 
    or stratocumulus, all having bases at the same level                                                       
3 - cumulonimbus, the summits of which, at least partially, lack sharp outlines 
    but are neither clearly fibrous (cirriform) nor in the form of an anvil; 
    cumulus, stratocumulus or stratus may also be present                                                              
4 - stratocumulus formed by the spreading out of cumulus; cumulus may also be 
    present                                                         
5 - stratocumulus not resulting from the spreading out of cumulus           
6 - stratus in a more or less continuous later, or in ragged shreds, or both but 
    no stratus fractus of bad weather                           
7 - stratus fractus of bad weather or cumulus fractus of bad weather, or both 
    (pannus), usually below altostratus or nimbostratus             
8 - cumulus and stratocumulus other than that formed from the spreading out of 
    cumulus; the base of the cumulus is at a different level from that of the 
    stratocumulus                          
9 - cumulonimbus, the upper part of which is clearly fibrous (cirriform) often in 
    the form of an anvil; either accompanied or not by cumulonimbus without anvil 
    or fibrous upper part, by cumulus, stratocumulus, stratus or pannus                          


Medium cloud type:

WMO code 0515: Clouds of the genera Altocumulus, Altostratus, etc.         

/ - altocumulus, altostratus and nimbostratus invisible owing to darkness, fog, 
    blowing dust, sand, or other phenomena; or because of the presence of a 
    continuous layer of lower clouds           
0 - no altocumulus, altostratus or nimbostratus                             
1 - altostratus, the greater part of which is semi-transparent; through this part 
    the sun or moon may be weakly visible, as through ground glass                                                 
2 - altostratus, the greater part of which is sufficiently dense to hide the sun 
    or moon, or nimbostratus                                   
3 - altocumulus, the greater part of which is semi-transparent; the various 
    elements of the cloud change only slowly and are all at a single level                                                            
4 - patches (often in the form of almonds or fish) of altocumulus, the greater 
    part of which is semi-transparent; the clouds occur at one or more levels 
    and the elements are continually changing in appearance                                                           
5 - semi-transparent altocumulus in bands, or altocumulus, in one or more 
    continuous layer (semi-transparent or opaque), progressively invading the 
    sky; these generally thicken as a whole                    
6 - altocumulus resulting from the spreading out of cumulus or cumulonimbus                                                            
7 - altocumulus in two or more layers, usually opaque in places, and not 
    progressively invading the sky; or opaque layer of altocumulus,not 
    progressively invading the sky; or altocumulus together with altostratus 
    or nimbostratus                               
8 - altocumulus with sproutings in the form of small towers or battlements, or 
    altocumulus having the appearance of cumuliform tufts                                                                   
9 - altocumulus of a chaotic sky, generally at several levels             


State of ground:

WMO code 0901: State of ground without snow or measurable ice cover.       

0 - ground dry (no cracks or appreciable amounts of dust/loose sand)        
1 - ground moist                                                            
2 - ground wet (standing water in small or large pools on surface)          
3 - flooded                                                                 
4 - ground frozen                                                           
5 - glaze on ground                                                         
6 - loose dry dust or sand not covering ground completely                   
7 - thin cover of loose dry dust or sand covering ground completely         
8 - mod/thick cover of loose dry dust/sand covering ground completely       
9 - extremely dry with cracks                                               


WMO code 0975: State of ground with snow or measurable ice cover.         

0 - ground predominantly covered by ice                                     
1 - compact/wet snow (with or without ice) covering less than 1/2 the ground                                                          
2 - compact/wet snow (with or without ice) covering at least 1/2 the ground                                                          
3 - even layer of compact or wet snow covering ground completely            
4 - uneven layer of compact or wet snow covering ground completely          
5 - loose dry snow covering less than 1/2 the ground                        
6 - loose dry snow covering at least 1/2 the ground (not completely)        
7 - even layer of loose dry snow covering ground completely                 
8 - uneven layer or loose dry snow covering ground completely               
9 - snow covering ground completely; deep drifts                          


Total cloud amount:


WMO code 2700: Cloud cover / amount         

/ - cloud is indiscernible for reasons other than fog or other meteorological 
    phenomena, or observation is not made.                   
0 - sky clear                                                               
1 - 1 okta : 1/10 - 2/10                                                    
2 - 2 oktas : 2/10 - 3/10                                                   
3 - 3 oktas : 4/10                                                          
4 - 4 oktas : 5/10                                                          
5 - 5 oktas : 6/10                                                          
6 - 6 oktas : 7/10 - 8/10                                                   
7 - 7 oktas or more, but not 8 oktas : 9/10 or more, but not 10/10          
8 - 8 oktas : 10/10                                                         
9 - sky obscured by fog or other meteorological phenomena                 


Past weather:

Past weather is defined as weather occurring in the past 6 hours at 00, 06, 12, 18 UTC, and the past 3 hours at 03, 09, 15, 21 UTC.

WMO code 4561: Past weather         

0 - cloud covering half or less of the sky throughout the period            
1 - cloud covering more than half the sky during part of the period & half or 
    less for the rest                                               
2 - cloud covering more than half the sky throughout the period             
3 - sandstorm, duststorm or blowing snow                                    
4 - fog or ice fog or thick haze                                            
5 - drizzle                                                                 
6 - rain1                                                                   
7 - snow, or rain and snow mixed                                            
8 - shower(s)                                                               
9 - thunderstorm(s) with or without precipitation                         


Present weather (from manned (code 4677) and automatic (4680) stations):

WMO code 4677: Present weather reported from a manned station.            

00 - Cloud development not observed or not observable                        
01 - Cloud generally dissolving or becoming less developed                   
02 - State of sky on the whole unchanged                                     
03 - Clouds generally forming or developing                                  
04 - Visibility reduced by smoke, e.g. veldt or forest fires, industrial smoke or 
     volcanic ashes                                      
05 - Haze                                                                    
06 - Widespread dust in suspension in the air, not raised by wind at or near the 
     station at the time of observation                          
07 - Dust or sand raised by wind at or near the station at the time of 
     observation, but not well-developed dust whirl(s) or sand whirl(s), 
     and no duststorm or sandstorm seen; or, in the case of ships, blowing 
     spray at the station                                     
08 - Well-developed dust or sand whirl(s) seen at or near the station during the 
     preceding hour or at the time of observation, but no dust storm or sandstorm                                                 
09 - Duststorm or sandstorm within sight at the time of observation, or at the 
     station during the preceding hour                             
10 - Mist                                                                    
11 - Patches of shallow fog or ice fog at the station, whether on land or sea not 
     deeper than about 2 metres on land or 10 metres at sea       
12 - More or less continuous shallow fog or ice fog at the station, whether on 
     land or sea, not deeper than about 2m/land or 10m/sea        
13 - Lightning visible, no thunder heard                                     
14 - Precipitation within sight, not reaching the ground or the surface of the 
     sea                                                  
15 - Precipitation within sight, reaching the ground or the surface of the sea, 
     but distant, i.e. > 5 km from the station                      
16 - Precipitation within sight, reaching the ground or the surface of the sea, 
     near to, but not at the station                                
17 - Thunderstorm, but no precipitation at the time of observation           
18 - Squalls at or within sight of the station during the preceding hour or at 
     the time of observation                                      
19 - Funnel clouds at or within sight of the station during the preceding hour or 
     at the time of observation                            
20 - Drizzle (not freezing) or snow grains, not falling as showers, during the 
     preceding hour but not at the time of observation            
21 - Rain (not freezing), not falling as showers, during the preceding hour but 
     not at the time of observation                                 
22 - Snow, not falling as showers, during the preceding hour but not at the 
     time of observation                                              
23 - Rain and snow or ice pellets, not falling as showers; during the preceding 
     hour but not at the time of observation                       
24 - Freezing drizzle or freezing rain; during the preceding hour but not at the 
     time of observation                                          
25 - Shower(s) of rain during the preceding hour but not at the time of 
     observation                                          
26 - Shower(s) of snow, or of rain and snow during the preceding hour but not at 
     the time of observation                                      
27 - Shower(s) of hail, or of rain and hail during the preceding hour but not at 
     the time of observation                                      
28 - Fog or ice fog during the preceding hour but not at the time of observation                                                             
29 - Thunderstorm (with or without precipitation) during the preceding hour but 
     not at the time of observation                                 
30 - Slight or moderate duststorm or sandstorm - has decreased during the 
     preceding hour                                                      
31 - Slight or moderate duststorm or sandstorm - no appreciable change during 
     the preceding hour                                               
32 - Slight or moderate duststorm or sandstorm - has begun or has increased 
     during the preceding hour                                     
33 - Severe duststorm or sandstorm - has decreased during the preceding hour                                                          
34 - Severe duststorm or sandstorm - no appreciable change during the preceding 
     hour                                                          
35 - Severe duststorm or sandstorm - has begun or has increased during the 
     preceding hour                                                      
36 - Slight/moderate drifting snow - generally low (below eye level)         
37 - Heavy drifting snow - generally low (below eye level)                   
38 - Slight/moderate blowing snow - generally high (above eye level)         
39 - Heavy blowing snow - generally high (above eye level)                   
40 - Fog or ice fog at a a distance at the time of observation, but not at 
     station during the preceding hour, the fog or ice fog extending to a 
     level above that of  the observer                        
41 - Fog or ice fog in patches                                               
42 - Fog/ice fog, sky visible, has become thinner during the preceding hour                                                                    
43 - Fog/ice fog, sky invisible, has become thinner during the preceding hour                                                          
44 - Fog or ice fog, sky visible, no appreciable change during the past hour                                                               
45 - Fog or ice fog, sky invisible, no appreciable change during the preceding 
     hour                                                          
46 - Fog or ice fog, sky visible, has begun or has become thicker during 
     preceding hour                                                   
47 - Fog or ice fog, sky invisible, has begun or has become thicker during the 
     preceding hour                                               
48 - Fog, depositing rime, sky visible                                       
49 - Fog, depositing rime, sky invisible                                     
50 - Drizzle, not freezing, intermittent, slight at time of ob.              
51 - Drizzle, not freezing, continuous, slight at time of ob.                
52 - Drizzle, not freezing, intermittent, moderate at time of ob.            
53 - Drizzle, not freezing, continuous, moderate at time of ob.              
54 - Drizzle, not freezing, intermittent, heavy at time of ob.               
55 - Drizzle, not freezing, continuous, heavy at time of ob.                 
56 - Drizzle, freezing, slight                                               
57 - Drizzle, freezing, moderate or heavy (dense)                            
58 - Rain and drizzle, slight                                                
59 - Rain and drizzle, moderate or heavy                                     
60 - Rain, not freezing, intermittent, slight at time of ob.                 
61 - Rain, not freezing, continuous, slight at time of ob.                   
62 - Rain, not freezing, intermittent, moderate at time of ob.               
63 - Rain, not freezing, continuous, moderate at time of ob.                 
64 - Rain, not freezing, intermittent, heavy at time of ob.                  
65 - Rain, not freezing, continuous, heavy at time of ob.                    
66 - Rain, freezing, slight                                                  
67 - Rain, freezing, moderate or heavy                                       
68 - Rain or drizzle and snow, slight                                        
69 - Rain or drizzle and snow, moderate or heavy                             
70 - Intermittent fall of snowflakes, slight at time of ob.                  
71 - Continuous fall of snowflakes, slight at time of ob.                    
72 - Intermittent fall of snowflakes, moderate at time of ob.                
73 - Continuous fall of snowflakes, moderate at time of ob.                  
74 - Intermittent fall of snowflakes, heavy at time of ob.                   
75 - Continuous fall of snowflakes, heavy at time of ob.                     
76 - Diamond dust (with or without fog)                                      
77 - Snow grains (with or without fog)                                       
78 - Isolated star-like snow crystals (with or without fog)                  
79 - Ice pellets                                                             
80 - Rain shower(s), slight                                                  
81 - Rain shower(s), moderate or heavy                                       
82 - Rain shower(s), violent                                                 
83 - Shower(s) of rain and snow, slight                                      
84 - Shower(s) of rain and snow, moderate or heavy                           
85 - Snow shower(s), slight                                                  
86 - Snow shower(s), moderate or heavy                                       
87 - Shower(s) of snow pellets or small hail, with or without rain or rain and 
     snow mixed - slight                                            
88 - Shower(s) of snow pellets or small hail, with or without rain or rain and 
     snow mixed - moderate or heavy                                 
89 - Shower(s) of hail, with or without rain or rain and snow mixed, not 
     associated with thunder - slight                                    
90 - Shower(s) of hail, with or without rain or rain and snow mixed, not 
     associated with thunder - moderate or heavy                         
91 - Slight rain at time of observation - Thunderstorm during the preceding hour 
     but not at time of observation                           
92 - Moderate or heavy rain at time of observation - Thunderstorm during the 
     preceding hour but not at time of observation                
93 - Slight snow, or rain and snow mixed or hail at time of observation - 
     Thunderstorm during the preceding hour but not at time of observation                                                     
94 - Moderate or heavy snow, or rain and snow mixed or hail at time of 
     observation - Thunderstorm during the preceding hour but not at 
     time of observation                                                  
95 - Thunderstorm, slight or moderate, without hail, but with rain and/or snow at 
     time of observation                                      
96 - Thunderstorm, slight or moderate, with hail at time of ob.              
97 - Thunderstorm, heavy, without hail, but with rain and/or snow at time of 
     observation                                                     
98 - Thunderstorm combined with dust/sandstorm at time of observation        
99 - Thunderstorm, heavy with hail at time of observation                    

WMO code 4680: Present weather reported from an automatic weather station.            

00 - No significant weather observed
01 - Clouds generally dissolving or becoming less developed during the past hour
02 - State of sky on the whole unchanged during the past hour
03 - Clouds generally forming or developing during the past hour
04 - Haze or smoke, or dust in suspension in the air, visibility equal to, or greater than, 1 km
05 - Haze or smoke, or dust in suspension in the air, visibility less than 1 km
06-09 - Reserved
10 - Mist
11 - Diamond dust
12 - Distant lightning
13-17 - Reserved
18 - Squalls
19 - Reserved

Code figures 20-26 are used to report precipitation, fog (or ice fog) or thunderstorm at the station 
during the preceding hour but not at the time of observation.

20 - Fog
21 - PRECIPITATION
22 - Drizzle (not freezing) or snow grains
23 - Rain (not freezing)
24 - Snow
25 - Freezing drizzle or freezing rain
26 - Thunderstorm (with or without precipitation)
27 - BLOWING OR DRIFTING SNOW OR SAND
28 - Blowing or drifting snow or sand, visibility equal to, or greater than, 1 km
29 - Blowing or drifting snow or sand, visibility less than 1 km
30 - FOG
31 - Fog or ice fog in patches
32 - Fog or ice fog, has become thinner during the past hour
33 - Fog or ice fog, no appreciable change during the past hour
34 - Fog or ice fog, has begun or become thicker during the past hour
35 - Fog, depositing rime
36-39 - Reserved
40 - PRECIPITATION
41 - Precipitation, slight or moderate
42 - Precipitation, heavy
43 - Liquid precipitation, slight or moderate
44 - Liquid precipitation, heavy
45 - Solid precipitation, slight or moderate
46 - Solid precipitation, heavy
47 - Freezing precipitation, slight or moderate
48 - Freezing precipitation, heavy
49 - Reserved
50 - DRIZZLE
51 - Drizzle, not freezing, slight
52 - Drizzle, not freezing, moderate
53 - Drizzle, not freezing, heavy
54 - Drizzle, freezing, slight
55 - Drizzle, freezing, moderate
56 - Drizzle, freezing, heavy
57 - Drizzle and rain, slight
58 - Drizzle and rain, moderate or heavy
59 - Reserved
60 - RAIN
61 - Rain, not freezing, slight
62 - Rain, not freezing, moderate
63 - Rain, not freezing, heavy
64 - Rain, freezing, slight
65 - Rain, freezing, moderate
66 - Rain, freezing, heavy
67 - Rain (or drizzle) and snow, slight
68 - Rain (or drizzle) and snow, moderate or heavy
69 - Reserved
70 - SNOW
71 - Snow, slight
72 - Snow, moderate
73 - Snow, heavy
74 - Ice pellets, slight
75 - Ice pellets, moderate
76 - Ice pellets, heavy
77 - Snow grains
78 - Ice crystals
79 - Reserved
80 - SHOWER(S) or INTERMITTENT PRECIPITATION
81 - Rain shower(s) or intermittent rain, slight
82 - Rain shower(s) or intermittent rain, moderate
83 - Rain shower(s) or intermittent rain, heavy
84 - Rain shower(s) or intermittent rain, violent
85 - Snow shower(s) or intermittent snow, slight
86 - Snow shower(s) or intermittent snow, moderate
87 - Snow shower(s) or intermittent snow, heavy
88 - Reserved
89 - Hail
90 - THUNDERSTORM
91 - Thunderstorm, slight or moderate, with no precipitation
92 - Thunderstorm, slight or moderate, with rain showers and/or snow showers
93 - Thunderstorm, slight or moderate, with hail
94 - Thunderstorm, heavy, with no precipitation
95 - Thunderstorm, heavy, with rain showers and/or snow showers
96 - Thunderstorm, heavy, with hail
97-98 - Reserved
99 - Tornado


Pressure characteristic over last 3 hours:

                    
WMO code 0200:Characteristic of pressure tendency.             

0 - Increasing, then decreasing : atmospheric pressure the same as or higher than 
    3 hrs ago                                                   
1 - Increasing, then steady : atmospheric pressure now higher than 3 hrs ago                                                          
2 - Increasing (steadily or unsteadily) : atmospheric pressure now higher than 
    3 hrs ago                                                   
3 - Decreasing or steady, then increasing; or increasing, then increasing more 
    rapidly : atmospheric pressure now higher than 3 hrs ago                                                               
4 - Steady : atmospheric pressure the same as 3 hrs ago                     
5 - Decreasing, then increasing : atmospheric pressure the same as or lower than 
    3 hrs ago                                                    
6 - Decreasing, then steady; or decreasing then decreasing more slowly : 
    atmospheric pressure now lower than 3 hrs ago                  
7 - Decreasing (steadily or unsteadily) : atmospheric pressure now lower than 
    3 hrs ago                                                    
8 - Steady or increasing, then decreasing; or decreasing, then decreasing more 
    rapidly : atmospheric pressure now lower than 3 hrs ago                                                             


Day of Thunder:

6000    NCM table 24

0 - no thunderstorm (0000-2400gmt)                                          
1 - thunderstorm with or without precipitation                              
9 - no thunderstorm (restricted period)                                   


Day of Hail:

6001    NCM table 23  

0 - no hail,ice,etc (0000-2400gmt)                                          
1 - diamond dust                                                            
2 - snow grains                                                             
3 - snow pellets                                                            
4 - ice pellets or small hail (less than 5mm diameter)                      
5 - hail ( diameter 5-9 mm)                                                 
6 - hail ( diameter 10-19 mm)                                               
7 - hail ( diameter 20mm or more )                                          
9 - no hail ,ice etc restricted period                                     


Day of snow or sleet:

6002    NCM table 27

0 - no snow or sleet(0000-2400gmt)                                          
1 - sleet                                                                   
5 - snow                                                                    
9 - no snow or sleet(restricted period)                                    


Day of fog:

6003    NCM table 25

0 - visibility 1000m or more at 0900 gmt(previous day)                      
1 - visibility less than 1000m at 0900 gmt                                 


Day of Gale:

6004    NCM table 26

0 - no gale(0000-2400 gmt)                                                  
1 - day on which wind speed has reached 34 knots (beaufort force 8) for a 
    period of at least 10 minutes                                     
9 - no gale (restricted period)                                            


State of concrete:

6005    NCM table 22  

/ - slab covered by snow or not adequately described by codes 0 to 3        
0 - slab dry                                                                
1 - slab moist                                                              
2 - slab wet                                                                
3 - slab icy                                                               


Snow lying at 0900GMT:

6006    CDB flag  

0 - no snow or less than half cover of snow lying                           
1 - more than half cover of snow at 0900z today                           


Snow depth:

001 - 1cm 
002 - 2cm
... - ...
996 - 996cm
997 - Less than 0.5cm
998 - Snow cover, not continuous
999 - Measurement impossible or inaccurate


020011 CLOUD AMOUNT 

0  0                                                                            
1  1 OKTA OR <1                                                                 
2  2 OKTAS                                                                      
3  3 OKTAS                                                                      
4  4 OKTAS                                                                      
5  5 OKTAS                                                                      
6  6 OKTAS                                                                      
7  7 OKTAS (<8)                                                                 
8  8 OKTAS                                                                      
9  SKY OBSCURED METEOROLOGICAL                                                  
10 SKY PARTLY  OBSCURED BY FOG AND/OR OTHER METEOROLOGICAL PHENOMENA            
11 SCATTERED                                                                    
12 BROKEN                                                                       
13 FEW                                                                          
 

020012 CLOUD TYPE 

0  CI                                                                           
1  CC                                                                           
2  CS                                                                           
3  AC                                                                           
4  AS                                                                           
5  NS                                                                           
6  SC                                                                           
7  ST                                                                           
8  CU                                                                           
9  CB                                                                           
10 NO CH CLOUDS                                                                 
11 CI FIB (UNC)                                                                 
12 CI SPI SHEAF                                                                 
13 CI SPI CUGEN                                                                 
14 CI UNC/FIB                                                                   
15 CI VEIL <45'                                                                 
16 CI VEIL >45'                                                                 
17 CS WHOLE SKY                                                                 
18 CS NOT COVER                                                                 
19 CH MOSTLY CC                                                                 
20 NO CM CLOUDS                                                                 
21 AS TR                                                                        
22 AS OP / NS                                                                   
23 AC TR LEVEL                                                                  
24 AC TR PATCHY                                                                 
25 AC TR BANDS                                                                  
26 AC CU(CB)GEN                                                                 
27 AC TR LAYERS                                                                 
28 AC CAS/FLO                                                                   
29 AC CHAOTIC                                                                   
30 NO CL CLOUDS                                                                 
31 CU HUM/FRA                                                                   
32 CU MED/CON                                                                   
33 CU CAL                                                                       
34 SC CUGEN                                                                     
35 SC NOT CUGEN                                                                 
36 SC NEB/FRA                                                                   
37 ST/CU FRA                                                                    
38 CU/SC LEVELS                                                                 
39 CB CAP                                                                       
40                                                                              
41                                                                              
42                                                                              
43                                                                              
44                                                                              
45                                                                              
46                                                                              
47                                                                              
48                                                                              
49                                                                              
50                                                                              
51                                                                              
52                                                                              
53                                                                              
54                                                                              
55                                                                              
56                                                                              
57                                                                              
58                                                                              
59 CLOUD INVIS                                                                  
60 CH INVISIBLE                                                                 
61 CM INVISIBLE                                                                 
62 CL INVISIBLE