34 Severe duststorm or sand- 

 storm. 



No appreciable 

 change during 

 preceding hour. 



35 Severe duststorm or sand- 

 storm . 



Has increased dur- 

 ing preceding 

 hour. 



36 



39 



Slight or moderate drifting 



snow. 

 Heavy drifting snow. 

 Slight or moderate drifting 



snow. 

 Heavy drifting snow. 



I. Fog at the time of observation. 



Fog at a distance at the time 

 of observation, but not at 

 the ship during the last 

 hour, the fog extending to a 

 level above that of the 

 observer. 



Generally low. 

 Generally high. 



41 Fog in patches. 



Fog, sky discernible. 

 Fog, sky not discernible. 



Has become thin- 

 ner during pre- 

 ceding hour. 



Fog, sky discernible. 

 Fog, sky not discernible. 



No appreciable 

 change during 

 preceding hour. 



Fog, sky discernible. 

 Fog, sky not discernible. 



Has begun or has 

 beco me thicker 

 during preceding 

 hour. 



48 Fog, depositing rime, sky dis- 



cernible. 



49 Fog, depositing rime, sky not 



discernible. 



50-99. Precipitation at the ship at the time of 

 observation. 



50-59. Drizzle at time of observation. 



50 Drizzle, not freezing, inter- Slight at time of 



mittent. observation. 



61 Drizzle, not freezing, continu- 

 ous. 



52 Drizzle, not freezing, inter- Moderate at time 



mittent. of observation. 



53 Drizzle, not freezing, continu- 



ous. 



64 Drizzle, not freezing, inter- Thick at time of 

 mittent. observation. 



55 Drizzle, not freezing, continu- 



ous. 



56 Drizzle, freezing, slight. 



57 Drizzle, freezing, moderate or 



thick. 

 68 Drizzle and rain, slight. 



59 Drizzle and rain, moderate or 



heavy. 



60-69. Rain at time of observation. 



60 Rain, not freezing, intermit- Slight at time of 



tent. observation. 



61 Rain, not freezing, continuous. 



62 Rain, not freezing, intermit- Moderate at time 



tent. of observation. 



63 Rain, not freezing, continuous. 



64 Rain, not freezing, intermit- 



tent. 



65 Rain, not freezing, continuous. 



Heavy at time of 

 observation. 



66 Rain, freezing, slight. 



67 Rain, freezing, moderate or 



heavy. 



68 Rain or drizzle and snow, 



slight. 



69 Rain or drizzle and snow, mod- 



erate or heavy. 



70-79. Solid precipitation not in showers at time of observation. 



70 Intermittent fall of snow flakes. Slight at time of 



71 Continuous fall of snow flakes. observation. 



Intermittent fall of snow flakes. 

 Continuous fall of snow flakes. 



Moderate at time 

 of observation. 



Intermittent fall of snow flakes. Heavy at time of 

 Continuous fall of snow flakes. observation. 



76 Ice needles (with or without 



fog). 



77 Granular snow (with or with- 



out fog). 



78 Isolated starlike snow crystals 



(with or without fog). 



79 Ice pellets. 

 precipitation with current or recent 



80 Rain shower(s), slight. 



81 Rain shower(s), moderate or 



heavy. 



82 Rain shower(s), violent. 



83 Shower (s) of rain and snow 



mixed, slight. 



84 Shower(s) of rain and snow 



mixed, moderate or heavy. 



85 Snow shower(s), slight. 



86 Snow shower(s), moderate or 



heavy. 



87 Shower (s) of soft or small hail 



with or without rain, or rain 

 and snow, slight. 



88 Shower (s) of soft or small hail 



with or without rain, or rain 

 and snow mixed, moderate 

 or heavy. 



89 Shower (s) of hail with or with- 



out rain, or rain and snow 

 mixed, not associated with 

 thunder, slight. 



90 Shower(s) of hail, with or with- 



out rain, or rain and snow 

 mixed, not associated with 

 thunder, moderate or heavy. 



Thunderstorm dur- 

 ing preceding 

 hour but not at 

 time of observa- 

 tion. 



Slight rain at time of observa- 

 tion. 



Moderate or heavy rain at 

 time of observation. 



Slight snow, or rain and snow 

 mixed, or hail* at time of 

 observation. 



Moderate or heavy snow, or 

 rain and snow mixed, or hail* 

 at time of observation. 



' Hail, small bail, soft bail. 



174 



H. O. 607 



