WEATHER TYPES ON THE PACIFIC COAST. 83 



of intense cyclonic areas originating in the Gulf of Mexico 

 or Texas and moving northeastward along the Atlantic 

 coast, accompanied by the most severe cold Avave of the 

 year east of the Eocky Mountains. Plate II illustrates this 

 type. 



THE GENERAL CYCLONIC TYPE. 



This type is characterized by the most severe storms that 

 occur on this coast. The rain area overspreads all sections, 

 falling in torrents, and gales of the greatest violence with 

 frequent thunderstorms occur, rivers overflow, and wash- 

 outs impede travel. The barometer drops very low and 

 suffers rapid fluctuations, and remarkable gradients occur 

 between the coast and interior. Simultaneous with this type 

 is a series of exceedingly high pressure waves over the Eocky 

 Mountain plateau and states to the eastward, accompanied 

 by severe storms and intense cold. During the last sea- 

 son there were only two occurrences of this type, viz., from 

 November 15th to 25th, and January 15th to 26th. The 

 general feature is a cyclonic disturbance on the Pacific 

 coast line, which, apparently unable to cross over the Sierra 

 Nevada, seems to spread out over the entire length of our 

 region, until it gradually wastes away or finds escape be- 

 yond the limits of our field of observation. The occurrence 

 of this type in January last is especially worthy of careful 

 review. On the 15th another surge of high pressure fol- 

 lowed the north Pacific anti-cyclonic of the first ten 

 days of January, extending from British xlmerica over the 

 Kocky Mountain region. On this coast was developed a 

 series of storms among the severest in the history of the 

 country. The temperature ^as very low in Montana, and 

 spread its influence over portions of this coast, causing 

 frost, snow, ice and unusual cold in portions of the Pa- 

 cific States. Eains were heavy and almost continuous, 

 gales frequent and severe, needing no description to those 

 who were here at the time. The storm, as represented by 



