Table 114. 

 BEAUFORT WEATHER NOTATION. 



Especially intended for the use of mariners, but sometimes used at land stations. 

 The original notation was devised in 1805 by Admiral Sir F. Beaufort; it has since 

 been slightly altered and amplified by British and American meteorologists. The 

 following symbols are used by the marine observers of the U. S. Weather Bureau : 



Upper Atmosphere : 



b. — Blue sky. 



c. — Cloudy sky. 



o. — Overcast sky. 

 Lower Atmosphere : 



v. — Visibility (exceptionally clear). 



z. — Haze, 

 m. — Mist. 



f.— Fog. 

 Precipitation : 



d. — Drizzling. 



p. — Passing showers. 



r. — Rain. 



s. — Snow. 



h.— Hail. 

 Electric phenomena : 



1. — Lightning. 



t. — Thunder. 

 Wind: 



q. — Squally. 



The British Meteorological Office also uses the following : 



e. — Wet air without rain. 

 g. — Gloom. 



u. — Ugly or threatening appearance of the weather, 

 w. — Dew. 



tl. — Thunderstorm. 

 KQ. — Line squall, 

 rs. — Sleet (rain and snow together), 

 fe.— Wet fog. 



y. — Dry air (less than 60% relative humidity). 

 X. — Hoarfrost. 



According to instructions to the marine meteorological observers of the U. S. 

 Weather Bureau, the underscoring of a letter denotes great intensity and double 

 underscoring very great intensity. 



The following instructions appear in the Meteorological Observer's Handbook of 

 the British Meteorological Office (1926 edition) : 



" Capital letters are used to indicate occasions when the phenomenon to be noted 

 is of unusual intensity. At the other end of the scale, occasions of slight intensity 

 are distinguished by adding a small suffix „. Thus, 



R. — Heavy rain, 

 r. — Moderate. 

 To. — Slight rain. 



and similarly with other phenomena. 



" Continuity is indicated by repeating the letter ; thus, 



RR. — Continuous heavy rain, 

 rr. — Continuous moderate rain. 



" The prefix ' i ' is used to indicate ' occasional ' or ' intermittent ' ; thus, 



if. — Occasional fog. 

 iro. — Intermittent slight rain." 



Smithsonian Tables. 



245 



