82 CALIFORNIA ACADEMY OF SCIENCES. 



NORTH PACIFIC ANTI-CYOLONIC TYPE. 



This type is very frequent, but sometimes of short dura- 

 tion. It prevailed from November lOtb to 15th; December 

 7th to 13th; December 31st to January 10th; February 

 12th to 21st; February 23d to 25th; March 10th to 12th; 

 March 23d to 28th; April 2d to 5th, and April 17th to 29th. 

 AYhile this type is prevalent the high, as is implied by its 

 name, rests over Oregon and Washington Territory, with a 

 permanent low over southern California. It is attended 

 with clear weather, only interrupted by an occasional 

 shower near Vancouver Island. During its prevalence in 

 its perfection and greatest intensity, and while the isobars 

 are perpendicular to the coast line, is the time when the 

 dreaded dessicating *' north wind" prevails in the Sacra- 

 mento and San Joaquin valleys. The temperature is high 

 during the day, especially after several days' continuance 

 of the type, while at night frosts often occur. The winds 

 are usually light and variable on the coast of Washington 

 Territory and Oregon, but on the coast of California high 

 with southerly gales. If in the spring during the preva- 

 lence of this type high winds and sandstorms occur in 

 southern California, they are almost sure to be followed by 

 rain. The proverb that a succession of frosts is liable to 

 be followed by rainy weather, obtains warrant from the fact 

 that the breaking up of this type is usually foretold by 

 frosts and most certainly followed by rain. The occurrence 

 of this type on the first ten days of January, 1886, appears to 

 bear a certain relation to the great surges of high pressure 

 from the Arctic regions moving well westward over British 

 Columbia. The isobar of 30.3 to 30.5 inches enclosed the 

 area. The weather on the coast was unusually cool and 

 clear; frosts extended into southern California. During 

 this period remarkably cold weather was prevailing in 

 the Eastern States. These surges of high pressure in their 

 movement covering almost the width of the continent dur- 

 ing the first ten days of January, caused the development 



